USAP-DC

{"dp_type": "Project", "free_text": "Photos"}

[{"awards": "2240780 Cohen, Natalie", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Mon, 13 Mar 2023 00:00:00 GMT", "description": "Mixotrophic microorganisms that are capable of both photosynthetic and heterotrophic forms of metabolism are key contributors to primary productivity and organic carbon remineralization in the Southern Ocean. However, uncertainties in their grazing behavior and physiology prevent an accurate understanding of microbial food web dynamics and biogeochemical cycling in the Antarctic ecosystem. Polar mixotrophs have evolved to withstand extreme seasonality, including variable light, sea ice, temperature, and micronutrient concentrations. In particular, the Southern Ocean appears to be the only region of the world\u2019s ocean where the bioessential trace metals iron (Fe) and manganese (Mn) are low enough to inhibit photosynthetic growth. The molecular physiology of mixotrophs experiencing Fe and Mn growth limitation has not yet been examined, and we lack an understanding of how seasonal changes in the availability of these micronutrients influence mixotrophic growth dynamics. We aim to examine whether grazing affords mixotrophs an ecological advantage in the Fe and Mn-deficient Southern Ocean, and to characterize the shifts in metabolic processes that occur during transitions in micronutrient conditions. Culture studies will directly measure growth responses, grazing behavior, and changes in elemental stoichiometry in response to Fe and Mn limitation. Transcriptomic analyses will reveal the metabolic underpinnings of trophic behavior and micronutrient stress responses, with implications for key biogeochemical processes such as carbon fixation, remineralization, and nutrient cycling. ", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "PLANKTON; Georgia; PHYTOPLANKTON", "locations": "Georgia", "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Cohen, Natalie; Millette, Nicole", "platforms": null, "repositories": null, "science_programs": null, "south": -90.0, "title": "ANT LIA: Collaborative Research: Mixotrophic Grazing as a Strategy to meet Nutritional Requirements in the Iron and Manganese Deficient Southern Ocean", "uid": "p0010411", "west": -180.0}, {"awards": "1744767 Sanders, Robert", "bounds_geometry": "POLYGON((-68 -64,-67.4 -64,-66.8 -64,-66.2 -64,-65.6 -64,-65 -64,-64.4 -64,-63.8 -64,-63.2 -64,-62.6 -64,-62 -64,-62 -64.5,-62 -65,-62 -65.5,-62 -66,-62 -66.5,-62 -67,-62 -67.5,-62 -68,-62 -68.5,-62 -69,-62.6 -69,-63.2 -69,-63.8 -69,-64.4 -69,-65 -69,-65.6 -69,-66.2 -69,-66.8 -69,-67.4 -69,-68 -69,-68 -68.5,-68 -68,-68 -67.5,-68 -67,-68 -66.5,-68 -66,-68 -65.5,-68 -65,-68 -64.5,-68 -64))", "dataset_titles": "Companion datasets to Diversity of microbial eukaryotes along the West Antarctic peninsula in austral spring.; Expedition Data of NBP1910; Expedition Data of NBP 2205; LMG1904 expedition data; NBP1910_protist_community_RNA Raw sequence reads; NBP2205_protist_community_RNA Raw sequence reads will be made available here after processing is completed", "datasets": [{"dataset_uid": "200366", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data of NBP 2205", "url": "https://www.rvdata.us/search/cruise/NBP2205"}, {"dataset_uid": "200320", "doi": "10.6084/m9.figshare.19514110.v3", "keywords": null, "people": null, "repository": "Figshare", "science_program": null, "title": "Companion datasets to Diversity of microbial eukaryotes along the West Antarctic peninsula in austral spring.", "url": "https://doi.org/10.6084/m9.figshare.19514110.v3"}, {"dataset_uid": "200325", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data of NBP1910", "url": "https://www.rvdata.us/search/cruise/NBP1910"}, {"dataset_uid": "200147", "doi": "10.7284/908260", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "LMG1904 expedition data", "url": "https://www.rvdata.us/search/cruise/LMG1904"}, {"dataset_uid": "200365", "doi": "", "keywords": null, "people": null, "repository": "NCBI", "science_program": null, "title": "NBP1910_protist_community_RNA Raw sequence reads; NBP2205_protist_community_RNA Raw sequence reads will be made available here after processing is completed", "url": "https://www.ncbi.nlm.nih.gov/search/all/?term=PRJNA807326"}], "date_created": "Wed, 27 Jul 2022 00:00:00 GMT", "description": "Traditional models of oceanic food chains have consisted of photosynthetic algae (phytoplankton) being ingested by small animals (zooplankton), which were ingested by larger animals (fish). These traditional models changed as new methods allowed recognition of the importance of bacteria and other non-photosynthetic protozoa in more complex food webs. More recently, the wide-spread existence of mixotrophs (organisms that can both photosynthesize and ingest food particles) and their importance as microbial predators has been recognized in many oceanographic areas. In the Southern Ocean, the only two surveys of mixotrophs have suggested that there may be seasonal differences in their importance as predators. During the long polar night (winter), the ability of mixotrophs to ingest particulate food may aid in their survival thus ensuring a sufficient population in spring to support a phytoplankton bloom once photosynthesis rates can increase. Thus mixotrophs may provide a critical early food source upon which zooplankton and larger animals depend on for growth and reproduction. This project will advance understanding of mixotroph diversity and their ecological impact within the Southern Ocean microbial food web. Specifically, efforts will be focused on mixotrophy in the western Antarctica peninsula region during the austral spring and autumn when there are likely to be changes in the relative importance of photosynthesis and ingestion to mixotrophs. The project will provide research opportunities for undergraduate and graduate students and a post-doctoral researcher. There will be real-time outreach from the Southern Ocean to the public via blogs and interviews, and to high school art students through an established program that blends science and art education. Despite traditional views of protists as either \"phototrophic\" or \"heterotrophic,\" there are many photosynthetic protists that consume prey (mixotrophy). Mixotrophy is a widespread phenomenon in aquatic systems and phytoplankton groups with known mixotrophic species, notably chrysophytes, cryptophytes, prymnesiophytes, prasinophytes and dinoflagellates, are present and often abundant in Antarctic waters. However, in the Southern Ocean, the presence of mixotrophic phytoflagellates has been surveyed only twice prior to this project: in the Ross Sea during Austral spring 2008 and summer 2011. The primary goals of the project are to gain better understanding of mixotroph diversity and their ecological impact with respect to the Southern Ocean microbial food web. The contribution of mixotrophs to primary production and bacterial consumption is likely linked to the taxonomic composition of the community and the abundance of particular species. Abundances of novel mixotrophic species will be evaluated via qPCR, which will be coupled with assessments of rates of feeding and photosynthesis with the goal of describing how active mixotrophs direct the movement of carbon through food webs. These experiments will help the determination of how viable and widespread mixotrophy is as a nutritional strategy in polar waters and give direct information on the currently unknown diversity of mixotrophic taxa under different environmental conditions occurring in austral spring and autumn. Furthermore, the methods will simultaneously yield information on the whole communities of protists - mixotrophic, phototrophic and heterotrophic. In addition, a method to examine aspects of the taxonomic and functional diversities of the bacterivorous/mixotrophic community will be employed. A thymidine analog (BrdU) will be used to label DNA of eukaryotes feeding on bacteria. The BrdU-labeled eukaryotic DNA will be isolated using immunoprecipitation. High-throughput sequencing of the labeled DNA (bacterivores) versus unlabeled community DNA will determine the diversity of bacterivorous mixotrophs relative to other microeukaryotes. Flow cytometric sorting based on chlorophyll to focus on mixotrophic species. These approaches will elucidate a gap in current knowledge of the influence of microbial interactions in the Southern Ocean under different conditions. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -62.0, "geometry": "POINT(-65 -66.5)", "instruments": null, "is_usap_dc": true, "keywords": "Antarctic Peninsula; PLANKTON; COASTAL", "locations": "Antarctic Peninsula", "north": -64.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Sanders, Robert; Gast, Rebecca; Jeffrey, Wade H.", "platforms": null, "repo": "R2R", "repositories": "Figshare; NCBI; R2R", "science_programs": null, "south": -69.0, "title": "Collaborative Research: Diversity and ecological impacts of Antarctic mixotrophic phytoplankton", "uid": "p0010357", "west": -68.0}, {"awards": "1745018 Fraser, William; 1745023 Hennon, Tyler; 1744884 Oliver, Matthew; 1745081 Bernard, Kim; 1745011 Klinck, John; 1745009 Kohut, Josh", "bounds_geometry": "POLYGON((-75 -60,-73 -60,-71 -60,-69 -60,-67 -60,-65 -60,-63 -60,-61 -60,-59 -60,-57 -60,-55 -60,-55 -61,-55 -62,-55 -63,-55 -64,-55 -65,-55 -66,-55 -67,-55 -68,-55 -69,-55 -70,-57 -70,-59 -70,-61 -70,-63 -70,-65 -70,-67 -70,-69 -70,-71 -70,-73 -70,-75 -70,-75 -69,-75 -68,-75 -67,-75 -66,-75 -65,-75 -64,-75 -63,-75 -62,-75 -61,-75 -60))", "dataset_titles": "Antarctic ACROBAT data; CTD Data from IFCB Sampling; Finite Time Lyapunov Exponent Results, Calculated from High Frequency Radar Observed Surface Currents; High Frequency Radar, Palmer Deep; IFCB Image Data; Relative Particle Density; SWARM AMLR moorings - acoustic data; SWARM Glider Data near Palmer Deep; WAP model float data; Winds from Joubin and Wauwerman Islands", "datasets": [{"dataset_uid": "200393", "doi": "10.26008/1912/bco-dmo.865002.1", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "IFCB Image Data", "url": "https://www.bco-dmo.org/dataset/865002"}, {"dataset_uid": "200396", "doi": "10.26008/1912/bco-dmo.867442.2", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "WAP model float data", "url": "https://www.bco-dmo.org/dataset/867442"}, {"dataset_uid": "200395", "doi": "10.26008/1912/bco-dmo.872729.1", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "SWARM AMLR moorings - acoustic data", "url": "https://www.bco-dmo.org/dataset/872729"}, {"dataset_uid": "200392", "doi": "10.26008/1912/bco-dmo.917884.1", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "High Frequency Radar, Palmer Deep", "url": "https://www.bco-dmo.org/dataset/917884"}, {"dataset_uid": "200398", "doi": "", "keywords": null, "people": null, "repository": "IOOS Glider DAAC", "science_program": null, "title": "SWARM Glider Data near Palmer Deep", "url": "https://gliders.ioos.us/erddap/search/index.html?page=1\u0026itemsPerPage=1000\u0026searchFor=swarm"}, {"dataset_uid": "200397", "doi": "10.26008/1912/bco-dmo.865098.1", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Winds from Joubin and Wauwerman Islands", "url": "https://www.bco-dmo.org/dataset/865098"}, {"dataset_uid": "200394", "doi": "10.26008/1912/bco-dmo.917926.1", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Relative Particle Density", "url": "https://www.bco-dmo.org/dataset/917926"}, {"dataset_uid": "200389", "doi": "", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Antarctic ACROBAT data", "url": "https://www.bco-dmo.org/dataset/916046"}, {"dataset_uid": "200390", "doi": "10.26008/1912/bco-dmo.865030.1", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "CTD Data from IFCB Sampling", "url": "https://www.bco-dmo.org/dataset/865030"}, {"dataset_uid": "200391", "doi": "10.26008/1912/bco-dmo.917914.1", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Finite Time Lyapunov Exponent Results, Calculated from High Frequency Radar Observed Surface Currents", "url": "https://www.bco-dmo.org/dataset/917914"}], "date_created": "Tue, 05 Jul 2022 00:00:00 GMT", "description": "Undersea canyons play disproportionately important roles as oceanic biological hotspots and are critical for our understanding of many coastal ecosystems. Canyon-associated biological hotspots have persisted for thousands of years Along the Western Antarctic Peninsula, despite significant climate variability. Observations of currents over Palmer Deep canyon, a representative hotspot along the Western Antarctic Peninsula, indicate that surface phytoplankton blooms enter and exit the local hotspot on scales of ~1-2 days. This time of residence is in conflict with the prevailing idea that canyon associated hotspots are primarily maintained by phytoplankton that are locally grown in association with these features by the upwelling of deep waters rich with nutrients that fuel the phytoplankton growth. Instead, the implication is that horizontal ocean circulation is likely more important to maintaining these biological hotspots than local upwelling through its physical concentrating effects. This project seeks to better resolve the factors that create and maintain focused areas of biological activity at canyons along the Western Antarctic Peninsula and create local foraging areas for marine mammals and birds. The project focus is in the analysis of the ocean transport and concentration mechanisms that sustain these biological hotspots, connecting oceanography to phytoplankton and krill, up through the food web to one of the resident predators, penguins. In addition, the research will engage with teachers from school districts serving underrepresented and underserved students by integrating the instructors and their students completely with the science team. Students will conduct their own research with the same data over the same time as researchers on the project. Revealing the fundamental mechanisms that sustain these known hotspots will significantly advance our understanding of the observed connection between submarine canyons and persistent penguin population hotspots over ecological time, and provide a new model for how Antarctic hotspots function.\u003cbr/\u003e \u003cbr/\u003e \u003cbr/\u003eTo understand the physical mechanisms that support persistent hotspots along the Western Antarctic Peninsula (WAP), this project will integrate a modeling and field program that will target the processes responsible for transporting and concentrating phytoplankton and krill biomass to known penguin foraging locations. Within the Palmer Deep canyon, a representative hotspot, the team will deploy a High Frequency Radar (HFR) coastal surface current mapping network, uniquely equipped to identify the eddies and frontal regions that concentrate phytoplankton and krill. The field program, centered on surface features identified by the HFR, will include (i) a coordinated fleet of gliders to survey hydrography, chlorophyll fluorescence, optical backscatter, and active acoustics at the scale of the targeted convergent features; (ii) precise penguin tracking with GPS-linked satellite telemetry and time-depth recorders (TDRs); (iii) and weekly small boat surveys that adaptively target and track convergent features to measure phytoplankton, krill, and hydrography. A high resolution physical model will generalize our field measurements to other known hotspots along the WAP through simulation and determine which physical mechanisms lead to the maintenance of these hotspots. The project will also engage educators, students, and members of the general public in Antarctic research and data analysis with an education program that will advance teaching and learning as well as broadening participation of under-represented groups. This engagement includes professional development workshops, live connections to the public and classrooms, student research symposia, and program evaluation. Together the integrated research and engagement will advance our understanding of the role regional transport pathways and local depth dependent concentrating physical mechanisms play in sustaining these biological hotspots.\u003cbr/\u003e\u003cbr/\u003eThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -55.0, "geometry": "POINT(-65 -65)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CONDUCTIVITY SENSORS \u003e CONDUCTIVITY METERS; IN SITU/LABORATORY INSTRUMENTS \u003e RADIATION SENSORS", "is_usap_dc": true, "keywords": "MOORED; WATER TEMPERATURE; CONDUCTIVITY; FLUORESCENCE; UNCREWED VEHICLES; Palmer Station; PHOTOSYNTHETICALLY ACTIVE RADIATION; PELAGIC; OCEAN MIXED LAYER; SURFACE; SALINITY; WATER PRESSURE; LIVING ORGANISM; MODELS; ACOUSTIC SCATTERING", "locations": "Palmer Station", "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Ocean and Atmospheric Sciences; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Integrated System Science; Antarctic Ocean and Atmospheric Sciences; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Instrumentation and Support", "paleo_time": "NOT APPLICABLE", "persons": "Bernard, Kim; Oliver, Matthew; Kohut, Josh; Fraser, William; Klinck, John M.; Statcewich, Hank", "platforms": "LIVING ORGANISM-BASED PLATFORMS \u003e LIVING ORGANISM; OTHER \u003e MODELS; WATER-BASED PLATFORMS \u003e BUOYS \u003e MOORED; WATER-BASED PLATFORMS \u003e UNCREWED VEHICLES; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE", "repo": "BCO-DMO", "repositories": "BCO-DMO; IOOS Glider DAAC", "science_programs": null, "south": -70.0, "title": "Collaborative Research: Physical Mechanisms Driving Food Web Focusing in Antarctic Biological Hotspots", "uid": "p0010346", "west": -75.0}, {"awards": "1951090 Stukel, Michael", "bounds_geometry": "POLYGON((-80 -63,-78.2 -63,-76.4 -63,-74.6 -63,-72.8 -63,-71 -63,-69.2 -63,-67.4 -63,-65.6 -63,-63.8 -63,-62 -63,-62 -63.7,-62 -64.4,-62 -65.1,-62 -65.8,-62 -66.5,-62 -67.2,-62 -67.9,-62 -68.6,-62 -69.3,-62 -70,-63.8 -70,-65.6 -70,-67.4 -70,-69.2 -70,-71 -70,-72.8 -70,-74.6 -70,-76.4 -70,-78.2 -70,-80 -70,-80 -69.3,-80 -68.6,-80 -67.9,-80 -67.2,-80 -66.5,-80 -65.8,-80 -65.1,-80 -64.4,-80 -63.7,-80 -63))", "dataset_titles": "BCO-DMO Project Page", "datasets": [{"dataset_uid": "200294", "doi": null, "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "BCO-DMO Project Page", "url": "https://www.bco-dmo.org/project/838048"}], "date_created": "Fri, 03 Jun 2022 00:00:00 GMT", "description": "Algae in the surface ocean convert carbon dioxide into organic carbon through photosynthesis. The biological carbon pump transports this organic carbon from the atmosphere to the deep ocean where it can be stored for tens to hundreds of years. Annually, the amount transported is similar to that humans are currently emitting by burning fossil fuels. However, at present we cannot predict how this important process will change with a warming ocean. These investigators plan to develop a 15+ year time-series of vertical carbon transfer for the Western Antarctic Peninsula; a highly productive Antarctic ecosystem. This region is also rapid transition to warmer temperatures leading to reduced sea ice coverage. This work will help researchers better understand how the carbon cycle in the Western Antarctic Peninsula will respond to climate change. The researchers will develop the first large-scale time-series of carbon flux anywhere in the ocean. This research will also support the education and training of a graduate student and support the integration of concepts in Antarctic research into two undergraduate courses designed for non-science majors and advanced earth science students. The researchers will also develop educational modules for introducing elementary and middle-school age students to important concepts such as gross and net primary productivity, feedbacks in the marine and atmospheric systems, and the differences between correlation and causation. Results from this proposal will also be incorporated into a children?s book, ?Plankton do the Strangest Things?, that is targeted at 5-7 year olds and is designed to introduce them to the incredible diversity and fascinating adaptations of microscopic marine organisms.\u003cbr/\u003e\u003cbr/\u003e This research seeks to leverage 6 years (2015-2020) of 234Th samples collected on Palmer LTER program, 5 years of prior measurements (2009-2010, 2012-2014), and upcoming cruises (2021-2023) to develop a time-series of summertime particle flux in the WAP that stretches for 15 years. The 238U-234Th disequilibrium approach utilizes changes in the activity of the particle-active radio-isotope 234Th relative to its parent nuclide 238U to quantify the flux of sinking carbon out of the surface ocean (over a time-scale of ~one month). This proposal will fund 234Th analyses from nine years? worth of cruises (2015-2023) and extensive analyses designed to investigate the processes driving inter-annual variability in the BCP. These include: 1) physical modeling to quantify the importance of advection and diffusion in the 234Th budget, 2) time-series analyses of particle flux, and 3) statistical modeling of the relationships between particle flux and multiple presumed drivers (biological, chemical, physical, and climate indices) measured by collaborators in the Palmer LTER program. This multi-faceted approach is critical for linking the measurements to models and for predicting responses to climate change. It will also test the hypothesis that export flux is decreasing in the northern WAP, increasing in the southern WAP, and increasing when integrated over the entire region as a result of earlier sea ice retreat and a larger ice-free zone. The project will also investigate relationships between carbon export and multiple potentially controlling factors including: primary productivity, algal biomass and taxonomic composition, biological oxygen saturation, zooplankton biomass and taxonomic composition, bacterial production, temperature, wintertime sea ice extent, date of sea ice retreat, and climate modes.\u003cbr/\u003e\u003cbr/\u003eThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -62.0, "geometry": "POINT(-71 -66.5)", "instruments": null, "is_usap_dc": true, "keywords": "Amd/Us; AMD; FIELD INVESTIGATION; Palmer Station; USAP-DC; BIOGEOCHEMICAL CYCLES; USA/NSF", "locations": "Palmer Station", "north": -63.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Stukel, Michael", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "BCO-DMO", "repositories": "BCO-DMO", "science_programs": null, "south": -70.0, "title": "Quantifying Processes Driving Interannual Variability in the Biological Carbon Pump in the Western Antarctic Peninsula", "uid": "p0010332", "west": -80.0}, {"awards": "2046240 Khan, Alia", "bounds_geometry": "POLYGON((-75 -62,-73.5 -62,-72 -62,-70.5 -62,-69 -62,-67.5 -62,-66 -62,-64.5 -62,-63 -62,-61.5 -62,-60 -62,-60 -62.85,-60 -63.7,-60 -64.55,-60 -65.4,-60 -66.25,-60 -67.1,-60 -67.95,-60 -68.8,-60 -69.65,-60 -70.5,-61.5 -70.5,-63 -70.5,-64.5 -70.5,-66 -70.5,-67.5 -70.5,-69 -70.5,-70.5 -70.5,-72 -70.5,-73.5 -70.5,-75 -70.5,-75 -69.65,-75 -68.8,-75 -67.95,-75 -67.1,-75 -66.25,-75 -65.4,-75 -64.55,-75 -63.7,-75 -62.85,-75 -62))", "dataset_titles": null, "datasets": null, "date_created": "Fri, 10 Sep 2021 00:00:00 GMT", "description": "Rapid and persistent climate warming in the Western Antarctic Peninsula is likely resulting in intensified snow-algae growth and an extended bloom season in coastal areas. Similarly, deposition of light absorbing particles (LAPs) onto Antarctica cryosphere surfaces, such as black carbon from intensifying Southern Hemisphere wildfire seasons, and dust from the expansion of ice-free regions in the Antarctic Peninsula, may be increasing. The presence of snow algae blooms and LAPs enhance the absorption of solar radiation by snow and ice surfaces. This positive feedback creates a measurable radiative forcing, which can have immediate local and long-term regional impacts on albedo, snow melt and downstream ecosystems. This project will investigate the spatial and temporal distribution of snow algae, black carbon and dust across the Western Antarctica Peninsula region, their response to climate warming, and their role in regional snow and ice melt. Data will be collected across multiple spatial scales from in situ field measurements and sample collection to imagery from ground-based photos and high resolution multi-spectral satellite sensors. Ground measurements will inform development and application of novel algorithms to map algal bloom extent through time using 0.5-3m spatial resolution multi-spectral satellite imagery. Results will be used to improve snow algae parameterization in a new version of the Snow Ice Aerosol Radiation model (SNICARv3) that includes bio-albedo feedbacks, eventually informing models of ice-free area expansion through incorporation of SNICARv3 in the Community Earth System Model. Citizen scientists will be mentored and engaged in the research through an active partnership with the International Association of Antarctic Tour Operators that frequently visits the region. The cruise ship association will facilitate sampling to develop a unique snow algae observing network to validate remote sensing algorithms that map snow algae with high-resolution multi-spectral satellite imagery from space. These time-series will inform instantaneous and interannual radiative forcing calculations to assess impacts of snow algae and LAPs on regional snow melt. Quantifying the spatio-temporal growing season of snow algae and impacts from black carbon and dust will increase our ability to model their impact on snow melt, regional climate warming and ice-free expansion in the Antarctic Peninsula region.", "east": -60.0, "geometry": "POINT(-67.5 -66.25)", "instruments": null, "is_usap_dc": true, "keywords": "FIELD SURVEYS; Antarctic Peninsula; Amd/Us; AMD; SNOW/ICE CHEMISTRY; USA/NSF; USAP-DC; SNOW", "locations": "Antarctic Peninsula", "north": -62.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Khan, Alia", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repositories": null, "science_programs": null, "south": -70.5, "title": "CAREER: Coastal Antarctic Snow Algae and Light Absorbing Particles: Snowmelt, Climate and Ecosystem Impacts", "uid": "p0010263", "west": -75.0}, {"awards": "1947562 van Gestel, Natasja; 1643871 van Gestel, Natasja", "bounds_geometry": "POLYGON((-65 -64.5,-64.8 -64.5,-64.6 -64.5,-64.4 -64.5,-64.2 -64.5,-64 -64.5,-63.8 -64.5,-63.6 -64.5,-63.4 -64.5,-63.2 -64.5,-63 -64.5,-63 -64.55,-63 -64.6,-63 -64.65,-63 -64.7,-63 -64.75,-63 -64.8,-63 -64.85,-63 -64.9,-63 -64.95,-63 -65,-63.2 -65,-63.4 -65,-63.6 -65,-63.8 -65,-64 -65,-64.2 -65,-64.4 -65,-64.6 -65,-64.8 -65,-65 -65,-65 -64.95,-65 -64.9,-65 -64.85,-65 -64.8,-65 -64.75,-65 -64.7,-65 -64.65,-65 -64.6,-65 -64.55,-65 -64.5))", "dataset_titles": null, "datasets": null, "date_created": "Sat, 21 Aug 2021 00:00:00 GMT", "description": "Responses of the carbon balance of terrestrial ecosystems to warming will feed back to the pace of climate change, but the size and direction of this feedback are poorly constrained. Least known are the effects of warming on carbon losses from soil, and clarifying the major microbial controls is an important research frontier. This study uses a series of experiments and observations to investigate microbial, including autotrophic taxa, and plant controls of net ecosystem productivity in response to warming in intact ecosystems. Field warming is achieved using open-top chambers paired with control plots, arrayed along a productivity gradient. Along this gradient incoming and outgoing carbon fluxes will be measured at the ecosystem-level. The goal is to tie warming-induced shifts in net ecosystem carbon balance to warming effects on soil microbes and plants. The field study will be supplemented with lab temperature incubations. Because soil microbes dominate biogeochemical cycles in Antarctica, a major focus of this study is to determine warming responses of bacteria, fungi and archaea. This is achieved using a cutting-edge stable isotope technique, quantitative stable isotope probing (qSIP) developed by the proposing research team, that can identify the taxa that are active and involved in processing new carbon. This technique can identify individual microbial taxa that are actively participating in biogeochemical cycling of nutrients (through combined use of 18O-water and 13C-bicarbonate) and thus can be distinguished from those that are simply present (cold-preserved). The study further assesses photosynthetic uptake of carbon by the vegetation and their sensitivity to warming. Results will advance research in climate change, plant and soil microbial ecology, and ecosystem modeling.", "east": -63.0, "geometry": "POINT(-64 -64.75)", "instruments": null, "is_usap_dc": true, "keywords": "Palmer Station; TERRESTRIAL ECOSYSTEMS; USA/NSF; AMD; Amd/Us; USAP-DC; FIELD SURVEYS", "locations": "Palmer Station", "north": -64.5, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Integrated System Science; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "van Gestel, Natasja", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repositories": null, "science_programs": null, "south": -65.0, "title": "Antarctica as a Model System for Responses of Terrestrial Carbon Balance to Warming", "uid": "p0010251", "west": -65.0}, {"awards": "1937748 Sumner, Dawn", "bounds_geometry": "POINT(163.183333 -77.616667)", "dataset_titles": null, "datasets": null, "date_created": "Wed, 30 Jun 2021 00:00:00 GMT", "description": "This project focuses on understanding annual changes in microbial life that grows on the bottom of Lake Fryxell, Antarctica. Because of its polar latitude, photosynthesis can only occur during the summer. During summer, photosynthetic bacteria supply communities with energy and oxygen. However, it is unknown how the microbes behave in the dark winter, when observations are not possible. This project will perform laboratory experiments with a cyanobacterial mat grown from Lake Fryxell samples. Once fieldwork is allowed, we will install environmental monitors and light-blocking shades over small parts of the communities in Lake Fryxell. The shades will extend winter conditions into the spring to allow researchers to characterize the winter behavior of the microbial communities. Researchers will measure changes in the water chemistry due to their activities when they first receive light as the shades are removed. Results are expected to provide insights into how organisms interact with and change their environments. \r\n\r\nThe project extends these scientific results to building a better-prepared, more diverse workforce to perform scientific fieldwork. Fieldwork, including diving, will be performed in part by graduate students under the mentorship of world experts in Antarctic field science. In addition, the project will help students and early career scientists learn field skills by building an online \u201cGuide to Thrive.\u201d This web site will compile field tips ranging from basic gear use to advanced environmental protection techniques. Group leaders ranging from undergraduate teaching assistants to Antarctic expedition leaders will be able to choose appropriate components to build tailored guides for their participants to help them thrive in difficult field conditions. \r\n\r\nThe researchers will measure laboratory-based and field-based seasonal metabolic and biogeochemical changes in benthic mats using differential gene expression and geochemical gradients. They will identify seasonal phenotypic differences and ecosystem effects induced by spring oxygen production. To do so, researchers will install environmental sensors and opaque shades over mats at three depths in the lake. The following spring, they will sample shaded and unshaded mats, remove the shades, track changes in pore water O2, H2S, pH, and redox with microelectrodes, and sample mats for transcriptomic analyses at intervals guided by geochemical changes. Pore water will be sampled for nutrient analyses. Field research will be supplemented with: laboratory experiments to refine field techniques (expanded effort due to COVID field restrictions); gene expression data analysis; and integration of results into a seasonal model of productivity and nitrogen cycling in Lake Fryxell. Results will provide insights into several key priorities for NSF, including how biotic, abiotic and environmental components of the benthic mats interact to affect the regional ecosystem.\r\n", "east": 163.183333, "geometry": "POINT(163.183333 -77.616667)", "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; Amd/Us; AMD; USA/NSF; FIELD SURVEYS; ECOSYSTEM FUNCTIONS; Lake Fryxell; USAP-DC; LAKE/POND", "locations": "Antarctica; Lake Fryxell", "north": -77.616667, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Integrated System Science", "paleo_time": null, "persons": "Sumner, Dawn; Mackey, Tyler", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repositories": null, "science_programs": null, "south": -77.616667, "title": "Seasonal Primary Productivity and Nitrogen Cycling in Photosynthetic Mats, Lake Fryxell, McMurdo Dry Valleys", "uid": "p0010219", "west": 163.183333}, {"awards": "1846837 Bowman, Jeff", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Fri, 25 Jun 2021 00:00:00 GMT", "description": "The coastal Antarctic is undergoing great environmental change. Physical changes in the environment, such as altered sea ice duration and extent, have a direct impact on the phytoplankton and bacteria species which form the base of the marine foodweb. Photosynthetic phytoplankton are the ocean\u0027s primary producers, transforming (fixing) CO2 into organic carbon molecules and providing a source of food for zooplankton and larger predators. When phytoplankton are consumed by zooplankton, or killed by viral attack, they release large amounts of organic carbon and nutrients into the environment. Heterotrophic bacteria must eat other things, and function as \"master recyclers\", consuming these materials and converting them to bacterial biomass which can feed larger organisms such as protists. Some protists are heterotrophs, but others are mixotrophs, able to grow by photosynthesis or heterotrophy. Previous work suggests that by killing and eating bacteria, protists and viruses may regulate bacterial populations, but how these processes are regulated in Antarctic waters is poorly understood. This project will use experiments to determine the rate at which Antarctic protists consume bacteria, and field studies to identify the major bacterial taxa involved in carbon uptake and recycling. In addition, this project will use new sequencing technology to obtain completed genomes for many Antarctic marine bacteria. To place this work in an ecosystem context this project will use microbial diversity data to inform rates associated with key microbial processes within the PALMER ecosystem model.\r\n\r\nThis project addresses critical unknowns regarding the ecological role of heterotrophic marine bacteria in the coastal Antarctic and the top-down controls on bacterial populations. Previous work suggests that at certain times of the year grazing by heterotrophic and mixotrophic protists may meet or exceed bacterial production rates. Similarly, in more temperate waters bacteriophages (viruses) are thought to contribute significantly to bacterial mortality during the spring and summer. These different top-down controls have implications for carbon flow through the marine foodweb, because protists are grazed more efficiently by higher trophic levels than are bacteria. This project uses a combination of grazing experiments and field observations to assess the temporal dynamics of mortality due to temperate bacteriophage and protists. Although many heterotrophic bacterial strains observed in the coastal Antarctic are taxonomically similar to strains from other regions, recent work suggest that they are phylogenetically and genetically distinct. To better understand the ecological function and evolutionary trajectories of key Antarctic marine bacteria, their genomes will be isolated and sequenced. Then, these genomes will be used to improve the predictions of the paprica metabolic inference pipeline, and our understanding of the relationship between heterotrophic bacteria and their major predators in the Antarctic marine environment. Finally, the research team will modify the Regional Test-Bed Model model to enable microbial diversity data to be used to optimize the starting conditions of key parameters, and to constrain the model\u0027s data assimilation methods.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Magmatic Volatiles; BACTERIA/ARCHAEA; VIRUSES; USA/NSF; Palmer Station; ECOSYSTEM FUNCTIONS; COMMUNITY DYNAMICS; LABORATORY; Amd/Us; PROTISTS; AMD; USAP-DC", "locations": "Palmer Station", "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Bowman, Jeff; Connors, Elizabeth", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": null, "title": "CAREER: Understanding microbial heterotrophic processes in coastal Antarctic waters", "uid": "p0010201", "west": null}, {"awards": "1246151 Bromirski, Peter; 1246416 Stephen, Ralph", "bounds_geometry": "POLYGON((-180 -77,-179.5 -77,-179 -77,-178.5 -77,-178 -77,-177.5 -77,-177 -77,-176.5 -77,-176 -77,-175.5 -77,-175 -77,-175 -77.4,-175 -77.8,-175 -78.2,-175 -78.6,-175 -79,-175 -79.4,-175 -79.8,-175 -80.2,-175 -80.6,-175 -81,-175.5 -81,-176 -81,-176.5 -81,-177 -81,-177.5 -81,-178 -81,-178.5 -81,-179 -81,-179.5 -81,180 -81,179 -81,178 -81,177 -81,176 -81,175 -81,174 -81,173 -81,172 -81,171 -81,170 -81,170 -80.6,170 -80.2,170 -79.8,170 -79.4,170 -79,170 -78.6,170 -78.2,170 -77.8,170 -77.4,170 -77,171 -77,172 -77,173 -77,174 -77,175 -77,176 -77,177 -77,178 -77,179 -77,-180 -77))", "dataset_titles": "Collaborative Research: Dynamic Response of the Ross Ice Shelf to Wave-Induced Vibrations and Collaborative Research: Mantle Structure and Dynamics of the Ross Sea from a Passive Seismic Deployment on the Ross Ice Shelf. International Federation of Digital Seismograph Networks. ; Dynamic Response of the Ross Ice Shelf to Wave-induced Vibrations 2015/2016, UNAVCO, Inc., GPS/GNSS Observations Dataset", "datasets": [{"dataset_uid": "200209", "doi": "10.7283/58E3-GA46", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "Dynamic Response of the Ross Ice Shelf to Wave-induced Vibrations 2015/2016, UNAVCO, Inc., GPS/GNSS Observations Dataset", "url": "https://doi.org/10.7283/58E3-GA46"}, {"dataset_uid": "200207", "doi": "10.7914/SN/XH_2014", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "Collaborative Research: Dynamic Response of the Ross Ice Shelf to Wave-Induced Vibrations and Collaborative Research: Mantle Structure and Dynamics of the Ross Sea from a Passive Seismic Deployment on the Ross Ice Shelf. International Federation of Digital Seismograph Networks. ", "url": "http://www.fdsn.org/networks/detail/XH_2014/"}], "date_created": "Thu, 15 Apr 2021 00:00:00 GMT", "description": "This award supports a project intended to discover, through field observations and numerical simulations, how ocean wave-induced vibrations on ice shelves in general, and the Ross Ice Shelf (RIS), in particular, can be used (1) to infer spatial and temporal variability of ice shelf mechanical properties, (2) to infer bulk elastic properties from signal propagation characteristics, and (3) to determine whether the RIS response to infragravity (IG) wave forcing observed distant from the front propagates as stress waves from the front or is \"locally\" generated by IG wave energy penetrating the RIS cavity. The intellectual merit of the work is that ocean gravity waves are dynamic elements of the global ocean environment, affected by ocean warming and changes in ocean and atmospheric circulation patterns. Their evolution may thus drive changes in ice-shelf stability by both mechanical interactions, and potentially increased basal melting, which in turn feed back on sea level rise. Gravity wave-induced signal propagation across ice shelves depends on ice shelf and sub-shelf water cavity geometry (e.g. structure, thickness, crevasse density and orientation), as well as ice shelf physical properties. Emphasis will be placed on observation and modeling of the RIS response to IG wave forcing at periods from 75 to 300 s. Because IG waves are not appreciably damped by sea ice, seasonal monitoring will give insights into the year-round RIS response to this oceanographic forcing. The 3-year project will involve a 24-month period of continuous data collection spanning two annual cycles on the RIS. RIS ice-front array coverage overlaps with a synergistic Ross Sea Mantle Structure (RSMS) study, giving an expanded array beneficial for IG wave localization. The ice-shelf deployment will consist of sixteen stations equipped with broadband seismometers and barometers. Three seismic stations near the RIS front will provide reference response/forcing functions, and measure the variability of the response across the front. A linear seismic array orthogonal to the front will consist of three stations in-line with three RSMS stations. Passive seismic array monitoring will be used to determine the spatial and temporal distribution of ocean wave-induced signal sources along the front of the RIS and estimate ice shelf structure, with the high-density array used to monitor and localize fracture (icequake) activity. The broader impacts include providing baseline measurements to enable detection of ice-shelf changes over coming decades which will help scientists and policy-makers respond to the socio-environmental challenges of climate change and sea-level rise. A postdoctoral scholar in interdisciplinary Earth science will be involved throughout the course of the research. Students at Cuyamaca Community College, San Diego County, will develop and manage a web site for the project to be used as a teaching tool for earth science and oceanography classes, with development of an associated web site on waves for middle school students.\n\r\nUnderstanding and being able to anticipate changes in the glaciological regime of the Ross Ice Shelf (RIS) and West Antarctic Ice Sheet (WAIS) are key to improving sea level rise projections due to ongoing ice mass loss in West Antarctica. The fate of the WAIS is a first-order climate change and global societal issue for this century and beyond that affects coastal communities and coastal infrastructure globally. \r\n\r\nIce shelf--ocean interactions include impacts from tsunami, ocean swell (10-30s period), and very long period ocean waves that impact ice shelves and produce vibrations that induce a variety of seismic signals detected by seismometers buried in the ice shelf surface layer, called firn. To study the wave-induced vibrations in the RIS, an extensive seismic array was deployed from Nov. 2014 to Nov. 2016. This unique seismometer array deployment on an ice shelf made continuous observations of the response of the RIS to ocean wave impacts from ocean swell and very long period waves. An extensive description of the project motivation and background (including photos and videos of the deployment operations), and list of published studies of analyses of the seismic data collected by this project, are available at the project website https://iceshelfvibes.ucsd.edu. \r\n\r\nTwo types of seismic signals detected by the seismic array are most prevalent: flexural gravity waves (plate waves) and icequakes (signals analogous to those from earthquakes but from fracturing of the ice). \r\nLong period ocean waves flex the ice shelf at the same period as the ocean waves, with wave energy at periods greater than ocean swell more efficient at coupling energy into flexing the ice shelf. Termed flexural gravity waves or plate waves (Chen et al., 2018), their wave-induced vibrations can reach 100\u2019s of km from the ice edge where they are excited, with long period wave energy propagating in the water layer below the shelf coupled with the ice shelf flexure. Flexural gravity waves at very long periods (\u003e 300 s period), such as from tsunami impacts (Bromirski et al., 2017), can readily reach grounding zones and may play a role in long-term grounding zone evolution. \r\nSwell-induced icequake activity was found to be most prevalent at the shelf front during the austral summer (January \u2013 March) when seasonal sea ice is absent and the associated damping of swell by sea ice is minimal (Chen et al., 2019). \r\n\r\nIn addition to the seismic array, a 14 station GPS (global positioning system) array was installed during seismic data retrieval and station servicing operations in October-November 2015. The GPS stations, co-located with seismic stations, extended from the shelf front southward to about 415 km at interior station RS18. Due to logistical constraints associated with battery weight during installation, only one station (at DR10) operated year-round. The GPS data collected give a detailed record of changes in iceflow velocity that are in close agreement with the increasing velocity estimates approaching the shelf front from satellite observations. Importantly, the year-round data at DR10 show an unprecedented seasonal cycle of changes in iceflow velocity, with a speed-up in northward (seaward) ice flow during Jan.-May and then a velocity decrease from June-Sep. (returning to the long-term mean flow velocity). This annual ice flow velocity change cycle has been attributed in part to seasonal changes in ice shelf mass (thinning, reducing buttressing) due to melting at the RIS basal (bottom) surface from intrusion of warmer ocean water (Klein et al., 2020). ", "east": 170.0, "geometry": "POINT(177.5 -79)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS", "is_usap_dc": true, "keywords": "FIELD INVESTIGATION; GLACIER MOTION/ICE SHEET MOTION; USAP-DC; Amd/Us; AMD; USA/NSF; Iris; Ross Ice Shelf", "locations": "Ross Ice Shelf", "north": -77.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Bromirski, Peter; Gerstoft, Peter; Stephen, Ralph", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "UNAVCO", "repositories": "IRIS; UNAVCO", "science_programs": null, "south": -81.0, "title": "Collaborative Research: Dynamic Response of the Ross Ice Shelf to Wave-induced Vibrations", "uid": "p0010169", "west": -175.0}, {"awards": "0732983 Vernet, Maria; 0732450 Van Dover, Cindy; 0732711 Smith, Craig; 0732917 McCormick, Michael", "bounds_geometry": "POLYGON((-60.5 -63.1,-59.99 -63.1,-59.48 -63.1,-58.97 -63.1,-58.46 -63.1,-57.95 -63.1,-57.44 -63.1,-56.93 -63.1,-56.42 -63.1,-55.91 -63.1,-55.4 -63.1,-55.4 -63.29,-55.4 -63.48,-55.4 -63.67,-55.4 -63.86,-55.4 -64.05,-55.4 -64.24,-55.4 -64.43,-55.4 -64.62,-55.4 -64.81,-55.4 -65,-55.91 -65,-56.42 -65,-56.93 -65,-57.44 -65,-57.95 -65,-58.46 -65,-58.97 -65,-59.48 -65,-59.99 -65,-60.5 -65,-60.5 -64.81,-60.5 -64.62,-60.5 -64.43,-60.5 -64.24,-60.5 -64.05,-60.5 -63.86,-60.5 -63.67,-60.5 -63.48,-60.5 -63.29,-60.5 -63.1))", "dataset_titles": "LARISSA: Impact of ice-shelf loss on geochemical profiles and microbial community composition in marine sediments of the Larsen A embayment, Antarctic Peninsula; NBP1001 cruise data; NBP1203 cruise data; Species Abundance Data from the Larsen Ice Shelf Ice acquired during R/V Nathaniel B. Palmer expedition NBP1203", "datasets": [{"dataset_uid": "000142", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP1001 cruise data", "url": "https://www.rvdata.us/search/cruise/NBP1001"}, {"dataset_uid": "000143", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP1203 cruise data", "url": "https://www.rvdata.us/search/cruise/NBP1203"}, {"dataset_uid": "601073", "doi": "10.15784/601073", "keywords": "Antarctica; Antarctic Peninsula; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; LARISSA; Microbiology", "people": "McCormick, Michael", "repository": "USAP-DC", "science_program": null, "title": "LARISSA: Impact of ice-shelf loss on geochemical profiles and microbial community composition in marine sediments of the Larsen A embayment, Antarctic Peninsula", "url": "https://www.usap-dc.org/view/dataset/601073"}, {"dataset_uid": "601304", "doi": null, "keywords": "Antarctica; Antarctic Peninsula; Biota; Box Corer; LARISSA; Larsen Ice Shelf; Macrofauna; Megafauna; NBP1203; Oceans; R/v Nathaniel B. Palmer; Seafloor Sampling; Species Abundance", "people": "Smith, Craig", "repository": "USAP-DC", "science_program": "LARISSA", "title": "Species Abundance Data from the Larsen Ice Shelf Ice acquired during R/V Nathaniel B. Palmer expedition NBP1203", "url": "https://www.usap-dc.org/view/dataset/601304"}], "date_created": "Fri, 09 Oct 2020 00:00:00 GMT", "description": "A profound transformation in ecosystem structure and function is occurring in coastal waters of the western Weddell Sea, with the collapse of the Larsen B ice shelf. This transformation appears to be yielding a redistribution of energy flow between chemoautotrophic and photosynthetic production, and to be causing the rapid demise of the extraordinary seep ecosystem discovered beneath the ice shelf. This event provides an ideal opportunity to examine fundamental aspects of ecosystem transition associated with climate change. We propose to test the following hypotheses to elucidate the transformations occurring in marine ecosystems as a consequence of the Larsen B collapse: (1) The biogeographic isolation and sub-ice shelf setting of the Larsen B seep has led to novel habitat characteristics, chemoautotrophically dependent taxa and functional adaptations. (2) Benthic communities beneath the former Larsen B ice shelf are fundamentally different from assemblages at similar depths in the Weddell sea-ice zone, and resemble oligotrophic deep-sea communities. Larsen B assemblages are undergoing rapid change. (3) The previously dark, oligotrophic waters of the Larsen B embayment now support a thriving phototrophic community, with production rates and phytoplankton composition similar to other productive areas of the Weddell Sea. To document rapid changes occurring in the Larsen B ecosystem, we will use a remotely operated vehicle, shipboard samplers, and moored sediment traps. We will characterize microbial, macrofaunal and megafaunal components of the seep community; evaluate patterns of surface productivity, export flux, and benthic faunal composition in areas previously covered by the ice shelf, and compare these areas to the open sea-ice zone. These changes will be placed within the geological, glaciological and climatological context that led to ice-shelf retreat, through companion research projects funded in concert with this effort. Together these projects will help predict the likely consequences of ice-shelf collapse to marine ecosystems in other regions of Antarctica vulnerable to climate change. The research features international collaborators from Argentina, Belgium, Canada, Germany, Spain and the United Kingdom. The broader impacts include participation of a science writer; broadcast of science segments by members of the Jim Lehrer News Hour (Public Broadcasting System); material for summer courses in environmental change; mentoring of graduate students and postdoctoral fellows; and showcasing scientific activities and findings to students and public through podcasts.", "east": -55.4, "geometry": "POINT(-57.95 -64.05)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NBP1203; USAP-DC; Amd/Us; LARISSA; Larsen Ice Shelf; Species Abundance Data; R/V NBP; Antarctic Peninsula; NBP1001; USA/NSF; AMD; Antarctica; MARINE ECOSYSTEMS", "locations": "Antarctica; Antarctic Peninsula; Larsen Ice Shelf", "north": -63.1, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Organisms and Ecosystems; Antarctic Integrated System Science; Antarctic Integrated System Science", "paleo_time": null, "persons": "McCormick, Michael; Vernet, Maria; Van Dover, Cindy; Smith, Craig", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R; USAP-DC", "science_programs": "LARISSA", "south": -65.0, "title": "Collaborative Research in IPY: Abrupt Environmental Change in the Larsen Ice Shelf System, a Multidisciplinary Approach - Marine Ecosystems.", "uid": "p0010135", "west": -60.5}, {"awards": "1745341 Sumner, Dawn", "bounds_geometry": "POLYGON((161.595 -77.527,161.5953 -77.527,161.5956 -77.527,161.5959 -77.527,161.5962 -77.527,161.5965 -77.527,161.5968 -77.527,161.5971 -77.527,161.5974 -77.527,161.5977 -77.527,161.598 -77.527,161.598 -77.5271,161.598 -77.5272,161.598 -77.5273,161.598 -77.5274,161.598 -77.5275,161.598 -77.5276,161.598 -77.5277,161.598 -77.5278,161.598 -77.5279,161.598 -77.528,161.5977 -77.528,161.5974 -77.528,161.5971 -77.528,161.5968 -77.528,161.5965 -77.528,161.5962 -77.528,161.5959 -77.528,161.5956 -77.528,161.5953 -77.528,161.595 -77.528,161.595 -77.5279,161.595 -77.5278,161.595 -77.5277,161.595 -77.5276,161.595 -77.5275,161.595 -77.5274,161.595 -77.5273,161.595 -77.5272,161.595 -77.5271,161.595 -77.527))", "dataset_titles": "GP0191362, Gp0191371; JAAXLU000000000, JAAXLT000000000", "datasets": [{"dataset_uid": "200152", "doi": "", "keywords": null, "people": null, "repository": "IMG Gold", "science_program": null, "title": "GP0191362, Gp0191371", "url": "https://gold.jgi.doe.gov/study?id=Gs0127369"}, {"dataset_uid": "200151", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "JAAXLU000000000, JAAXLT000000000", "url": "https://www.ncbi.nlm.nih.gov/nuccore/JAAXLU000000000"}], "date_created": "Mon, 22 Jun 2020 00:00:00 GMT", "description": "Atmospheric oxygen rose suddenly approximately 2.4 billion years ago after Cyanobacteria evolved the ability to produce oxygen through photosynthesis (oxygenic photosynthesis). This change permanently altered the future of life on Earth, yet little is known about the evolutionary processes leading to it. The Melainabacteria were first discovered in 2013 and are closely related non-photosynthetic relatives of the first group of organisms capable of oxygenic photosynthesis. This project will utilize existing data on metagenomes from microbial mats in Lake Vanda, an ice-covered lake in Antarctica where many sequences of Melainabacteria have been previously identified. \r\n\r\nFrom this genetic information, we identified a new cyanobacterium, named Aurora vandensis, that is sister to all other Cyanobacteria, providing evolutionary insights. In addition, we assessed the metabolic capabilities of the Melainabacteria with good genomic coverage to identify their potential ecological roles. None contain photosynthetic genes, and we are evaluating the evolutionary relationships among the Cyanobacteria and Melainabacteria, particularly with respect to metabolic genes that will allow an advancement in understanding of the evolutionary path that lead to oxygenic photosynthesis on Earth.\r\n\r\nThe project will focus on extracting evolutionary information from the genomic data of Melainabacteria and Sericytochromatia, recently-described groups closely related to but basal to the Cyanobacteria. The characterization of novel members of these groups in samples from Lake Vanda, Antarctica, provide insights into the path and processes involved in the evolution of oxygenic photosynthesis. The research identified a novel cyanobacterial genus that is sister to all other Cyanobacteria, is most closely related to Gloeobacter, and shares evolutionary differences with that genus. Results also show that characterized Melainabacteria lack photosynthesis genes, but their respiration genes provide insight into evolutionary relationships among Melainabacteria and Cyanobacteria. Results provide unexpected constraints. The project focuses on 12 metagenomes, from which Melainabacteria and novel Cyanobacteria bins are annotated and preliminary metabolic pathways will be constructed. The project utilizes full-length sequences of marker genes from across the bacterial domain with a particular focus on taxa that are oxygenic or anoxygenic phototrophs and use the marker genes, to build a rooted \"backbone\" tree. Incomplete or short sequences from the metagenomes are added to the tree using the Evolutionary Placement Algorithm. The researchers built a corresponding phylogenetic tree using a Bayesian framework and compare their topologies. By doing so, the project aims to improve the understanding of the evolution of oxygenic photosynthesis, which caused the most significant change in Earth\u0027s surface chemistry. Specifically, we document a novel and basal cyanobacterium, significantly broader metabolic diversity within the Melainabacteria than has been previously identified, gain significant insights into their metabolic evolution, their evolutionary relationships with the Cyanobacteria, and the evolutionary steps leading to the origin of oxygenic photosynthesis. This research is constraining key evolutionary processes in the origin of oxygenic photosynthesis. It provides the foundation for future studies by indicating where a genomic record of the evolution of oxygenic photosynthesis may be preserved. Results will are being shared with middle school children through the development of scientific lesson plans in collaboration with teachers.\r\n\r\nThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 161.598, "geometry": "POINT(161.5965 -77.5275)", "instruments": null, "is_usap_dc": true, "keywords": "USAP-DC; FIELD INVESTIGATION; CYANOBACTERIA (BLUE-GREEN ALGAE); Lake Vanda; LABORATORY; LAKE/POND; Genetic Analysis", "locations": "Lake Vanda", "north": -77.527, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Sumner, Dawn; Eisen, Jonathan; Tazi, Loubna", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "IMG Gold", "repositories": "IMG Gold; NCBI GenBank", "science_programs": null, "south": -77.528, "title": "Evolution of Oxygenic Photosynthesis as Preserved in Melainabacterial Genomes from Lake Vanda, Antarctica", "uid": "p0010112", "west": 161.595}, {"awards": "1443470 Aydin, Murat", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "South Pole ice core (SPC14) discrete methane data; SP19 Gas Chronology; SPC14 carbonyl sulfide, methyl chloride, and methyl bromide measurements from South Pole, Antarctica", "datasets": [{"dataset_uid": "601380", "doi": "10.15784/601380", "keywords": "Antarctica; Ch4; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Ice Core Stratigraphy; Methane; South Pole; SPICEcore", "people": "Epifanio, Jenna", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "SP19 Gas Chronology", "url": "https://www.usap-dc.org/view/dataset/601380"}, {"dataset_uid": "601381", "doi": "10.15784/601381", "keywords": "Antarctica; Ch4; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Data; Ice Core Records; Methane; South Pole; SPICEcore", "people": "Kahle, Emma; Sowers, Todd A.; Edwards, Jon S.; Kennedy, Joshua A.; Aydin, Murat; Kreutz, Karl; Buizert, Christo; Brook, Edward J.; Epifanio, Jenna; Fudge, T. J.; Osterberg, Erich; Winski, Dominic A.; Hood, Ekaterina; Kalk, Michael; Steig, Eric J.; Ferris, David G.; Severinghaus, Jeffrey P.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole ice core (SPC14) discrete methane data", "url": "https://www.usap-dc.org/view/dataset/601381"}, {"dataset_uid": "601270", "doi": "10.15784/601270", "keywords": "Antarctica", "people": "Aydin, Murat", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "SPC14 carbonyl sulfide, methyl chloride, and methyl bromide measurements from South Pole, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601270"}], "date_created": "Thu, 26 Mar 2020 00:00:00 GMT", "description": "In the past, Earth\u0027s climate underwent dramatic changes that influenced physical, chemical, geological, and biological processes on a global scale. Such changes left an imprint in Earth\u0027s atmosphere, as shown by the variability in abundances of trace gases like carbon dioxide and methane. In return, changes in the atmospheric trace gas composition affected Earth\u0027s climate. Studying compositional variations of the past atmosphere helps us understand the history of interactions between global biogeochemical cycles and Earth?s climate. The most reliable information on past atmospheric composition comes from analysis of air entrapped in polar ice cores. This project aims to generate ice-core records of relatively short-lived, very-low-abundance trace gases to determine the range of past variability in their atmospheric levels and investigate the changes in global biogeochemical cycles that caused this variability. This project measures three such gases: carbonyl sulfide, methyl chloride, and methyl bromide. Changes in carbonyl sulfide can indicate changes in primary productivity and photosynthetic update of carbon dioxide. Changes in methyl chloride and methyl bromide significantly impact natural variability in stratospheric ozone. In addition, the processes that control atmospheric levels of methyl chloride and methyl bromide are shared with those controlling levels of atmospheric methane. The measurements will be made in the new ice core from the South Pole, which is expected to provide a 40,000-year record.\u003cbr/\u003e\u003cbr/\u003eThe primary focus of this project is to develop high-quality trace gas records for the entire Holocene period (the past 11,000 years), with additional, more exploratory measurements from the last glacial period including the period from 29,000-36,000 years ago when there were large changes in atmospheric methane. Due to the cold temperatures of the South Pole ice, the proposed carbonyl sulfide measurements are expected to provide a direct measure of the past atmospheric variability of this gas without the large hydrolysis corrections that are necessary for interpretation of measurements from ice cores in warmer settings. Furthermore, we will test the expectation that contemporaneous measurements from the last glacial period in the deep West Antarctic Ice Sheet Divide ice core will not require hydrolysis loss corrections. With respect to methyl chloride, we aim to verify and improve the existing Holocene atmospheric history from the Taylor Dome ice core in Antarctica. The higher resolution of our measurements compared with those from Taylor Dome will allow us to derive a more statistically significant relationship between methyl chloride and methane. With respect to methyl bromide, we plan to extend the existing 2,000-year database to 11,000 years. Together, the methyl bromide and methyl chloride records will provide strong measurement-based constraints on the natural variability of stratospheric halogens during the Holocene period. In addition, the methyl bromide record will provide insight into the correlation between methyl chloride and methane during the Holocene period due to common sources and sinks.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; CARBONYL SULFIDE; HALOCARBONS AND HALOGENS; TRACE GASES/TRACE SPECIES; Antarctic; USAP-DC", "locations": "Antarctic", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Aydin, Murat", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Carbonyl Sulfide, Methyl Chloride, and Methyl Bromide Measurements in the New Intermediate-depth South Pole Ice Core", "uid": "p0010089", "west": -180.0}, {"awards": "1443371 Fountain, Andrew", "bounds_geometry": "POLYGON((160.2 -77.1,160.57 -77.1,160.94 -77.1,161.31 -77.1,161.68 -77.1,162.05 -77.1,162.42 -77.1,162.79 -77.1,163.16 -77.1,163.53 -77.1,163.9 -77.1,163.9 -77.196,163.9 -77.292,163.9 -77.388,163.9 -77.484,163.9 -77.58,163.9 -77.676,163.9 -77.772,163.9 -77.868,163.9 -77.964,163.9 -78.06,163.53 -78.06,163.16 -78.06,162.79 -78.06,162.42 -78.06,162.05 -78.06,161.68 -78.06,161.31 -78.06,160.94 -78.06,160.57 -78.06,160.2 -78.06,160.2 -77.964,160.2 -77.868,160.2 -77.772,160.2 -77.676,160.2 -77.58,160.2 -77.484,160.2 -77.388,160.2 -77.292,160.2 -77.196,160.2 -77.1))", "dataset_titles": "McMurdo Dry Valleys LTER: A digital archive of human activity in the McMurdo Dry Valleys, Antarctica from 1902 to present", "datasets": [{"dataset_uid": "200086", "doi": "10.6073/pasta/0725cbd31f2af4bca2c6ad145e38dd3a", "keywords": null, "people": null, "repository": "EDI", "science_program": null, "title": "McMurdo Dry Valleys LTER: A digital archive of human activity in the McMurdo Dry Valleys, Antarctica from 1902 to present", "url": "https://doi.org/10.6073/pasta/0725cbd31f2af4bca2c6ad145e38dd3a"}], "date_created": "Thu, 21 Nov 2019 00:00:00 GMT", "description": "Beginning with the discovery of a \"curious valley\" in 1903 by Captain Scott, the McMurdo Dry Valleys (MDV) in Antarctica have been impacted by humans, although there were only three brief visits prior to 1950. Since the late 1950\u0027s, human activity in the MDV has become commonplace in summer, putting pressure on the region\u0027s fragile ecosystems through camp construction and inhabitation, cross-valley transport on foot and via vehicles, and scientific research that involves sampling and deployment of instruments. Historical photographs, put alongside information from written documentation, offer an invaluable record of the changing patterns of human activity in the MDV. Photographic images often show the physical extent of field camps and research sites, the activities that were taking place, and the environmental protection measures that were being followed. Historical photographs of the MDV, however, are scattered in different places around the world, often in private collections, and there is a real danger that many of these photos may be lost, along with the information they contain. This project will collect and digitize historical photographs of sites of human activity in the MDV from archives and private collections in the United States, New Zealand, and organize them both chronologically and spatially in a GIS database. Sites of past human activities will be re-photographed to provide comparisons with the present, and re-photography will assist in providing spatial data for historical photographs without obvious location information. The results of this analysis will support effective environmental management into the future. The digital photo archive will be openly available through the McMurdo Dry Valleys Long Term Ecological Research (MCM LTER) website (www.mcmlter.org), where it can be used by scientists, environmental managers, and others interested in the region. \u003cbr/\u003e\u003cbr/\u003eThe central question of this project can be reformulated as a hypothesis: Despite an overall increase in human activities in the MDV, the spatial range of these activities has become more confined over time as a result of an increased awareness of ecosystem fragility and efforts to manage the region. To address this hypothesis, the project will define the spatial distribution and temporal frequency of human activity in the MDV. Photographs and reports will be collected from archives with polar collections such as the National Archives of New Zealand in Wellington and Christchurch and the Byrd Polar Research Center in Ohio. Private photograph collections will be accessed through personal connections, social media, advertisements in periodicals such as The Polar Times, and other means. Re-photography in the field will follow established techniques and will create benchmarks for future research projects. The spatial data will be stored in an ArcGIS database for analysis and quantification of the human footprint over time in the MDV. The improved understanding of changing patterns of human activity in the MDV provided by this historical photo archive will provide three major contributions: 1) a fundamentally important historic accounting of human activity to support current environmental management of the MDV; 2) defining the location and type of human activity will be of immediate benefit in two important ways: a) places to avoid for scientists interested in sampling pristine landscapes, and, b) targets of opportunity for scientists investigating the long-term environmental legacy of human activity; and 3) this research will make an innovative contribution to knowledge of the environmental history of the MDV.", "east": 163.9, "geometry": "POINT(162.05 -77.58)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "CONTAMINANT LEVELS/SPILLS; Antarctica; NOT APPLICABLE; USAP-DC", "locations": "Antarctica", "north": -77.1, "nsf_funding_programs": "Antarctic Integrated System Science", "paleo_time": null, "persons": "Fountain, Andrew; Howkins, Adrian", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "EDI", "repositories": "EDI", "science_programs": null, "south": -78.06, "title": "Collaborative Research: Assessing Changing Patterns of Human Activity in the McMurdo Dry Valleys using Digital Photo Archives", "uid": "p0010066", "west": 160.2}, {"awards": "1443578 Schmidt, Steven", "bounds_geometry": "POLYGON((161.5 -77.5,161.7 -77.5,161.9 -77.5,162.1 -77.5,162.3 -77.5,162.5 -77.5,162.7 -77.5,162.9 -77.5,163.1 -77.5,163.3 -77.5,163.5 -77.5,163.5 -77.53,163.5 -77.56,163.5 -77.59,163.5 -77.62,163.5 -77.65,163.5 -77.68,163.5 -77.71,163.5 -77.74,163.5 -77.77,163.5 -77.8,163.3 -77.8,163.1 -77.8,162.9 -77.8,162.7 -77.8,162.5 -77.8,162.3 -77.8,162.1 -77.8,161.9 -77.8,161.7 -77.8,161.5 -77.8,161.5 -77.77,161.5 -77.74,161.5 -77.71,161.5 -77.68,161.5 -77.65,161.5 -77.62,161.5 -77.59,161.5 -77.56,161.5 -77.53,161.5 -77.5))", "dataset_titles": "16S and 18S amplicon sequencing of Antarctic cryoconite holes; Genomes of Antarctic ssDNA viruses (GenBank accession numbers MN311489-MN311492 and MN328267-MN328291); Metadata from samples (in the process of submitting to EDI; will update with DOI once completed); Microbial species-area relationships in Antarctic cryoconite holes; Soil microbial communities of a mountain landscape, McMurdo Dry Valleys, Antarctica", "datasets": [{"dataset_uid": "200281", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Microbial species-area relationships in Antarctic cryoconite holes", "url": "https://www.ncbi.nlm.nih.gov/bioproject/PRJNA668398/"}, {"dataset_uid": "200084", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Genomes of Antarctic ssDNA viruses (GenBank accession numbers MN311489-MN311492 and MN328267-MN328291)", "url": ""}, {"dataset_uid": "200280", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Soil microbial communities of a mountain landscape, McMurdo Dry Valleys, Antarctica", "url": "https://www.ncbi.nlm.nih.gov/bioproject/PRJNA721735/"}, {"dataset_uid": "200279", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "Metadata from samples (in the process of submitting to EDI; will update with DOI once completed)", "url": "https://github.com/pacificasommers/Cryoconite-metadata"}, {"dataset_uid": "200081", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "16S and 18S amplicon sequencing of Antarctic cryoconite holes", "url": "https://www.ncbi.nlm.nih.gov/bioproject/PRJNA480849/"}], "date_created": "Fri, 01 Nov 2019 00:00:00 GMT", "description": "Cryoconite holes are pockets of life completely encased in otherwise barren glacial ice. These pockets of life form when dust blown onto the ice melts a small, largely isolated hole that can function as its own tiny ecosystem. This dust can contain microorganisms such as bacteria, algae, or microscopic animals. The microorganisms within the hole interact and carry out functions typical of a larger ecosystem, such as a forest. Cryoconite holes are especially important in extreme cold environments such as the Antarctic Dry Valleys, where they function as repositories of life. Because cryoconite holes are mostly enclosed and persist for years, they can be tracked over time to test fundamental scientific questions about how communities of interacting organisms develop to become fully functioning ecosystems. This project will sample existing and experimentally created cryoconite holes to understand how these ecosystems develop and to what degree random processes (such as which organisms get there first) affect the final community composition and functioning. The results will not only improve our understanding of how microbial communities assemble and affect the functioning of microecosystems such as cryoconite holes, but also how the processes of community assembly affect functioning of larger ecosystems, such as forests. A better understanding of community establishment, development, and response to abiotic factors are essential to forecasting ecological responses to environmental change.\u003cbr/\u003e\u003cbr/\u003eIt is essential to unravel the links between community assembly, biodiversity, and nutrient cycling across numerous ecosystems because these are critical factors determining ecological responses to environmental change. The unique, largely isolated nature of cryoconite holes provides an experimental system that will advance fundamental understanding of the processes (e.g., stochastic dynamics such as dispersal limitation, assembly order, and ecological drift) driving community assembly. This project will use a field sampling campaign and a number of manipulative experiments to test a hypothesis that unites theory in community and ecosystem ecology: the degree to which stochastic processes guide microbial community assembly and affects regional patterns in biodiversity and ecosystem processes. Cryoconite holes will be sampled to compare community composition, environmental factors, and ecosystem functioning between hydrologically connected and isolated holes. New cryoconite holes will also be constructed and monitored over the course of two growing seasons to specifically alter assembly order and community size, thereby pairing a unique manipulative experiment with field surveys to address questions with relevance to the Antarctic and beyond. Amplicon sequencing, metagenomics, microscopy, sensitive environmental chemistry methods, and photosynthesis and respiration measurements will be used to test a series of sub-hypotheses that relate stochasticity to patterns in regional biodiversity, heterogeneity in environmental factors, and ecosystem processes.", "east": 163.5, "geometry": "POINT(162.5 -77.65)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "GLACIERS; Antarctica; USAP-DC; FIELD INVESTIGATION", "locations": "Antarctica", "north": -77.5, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Schmidt, Steven; Cawley, Kaelin; Fountain, Andrew", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "NCBI GenBank", "repositories": "GitHub; NCBI GenBank", "science_programs": null, "south": -77.8, "title": "Collaborative Research: Stochasticity and Cryoconite Community Assembly and Function", "uid": "p0010063", "west": 161.5}, {"awards": "1744645 Young, Jodi", "bounds_geometry": "POLYGON((-64.4 -64.2,-64.38 -64.2,-64.36 -64.2,-64.34 -64.2,-64.32 -64.2,-64.3 -64.2,-64.28 -64.2,-64.26 -64.2,-64.24 -64.2,-64.22 -64.2,-64.2 -64.2,-64.2 -64.26,-64.2 -64.32,-64.2 -64.38,-64.2 -64.44,-64.2 -64.5,-64.2 -64.56,-64.2 -64.62,-64.2 -64.68,-64.2 -64.74,-64.2 -64.8,-64.22 -64.8,-64.24 -64.8,-64.26 -64.8,-64.28 -64.8,-64.3 -64.8,-64.32 -64.8,-64.34 -64.8,-64.36 -64.8,-64.38 -64.8,-64.4 -64.8,-64.4 -64.74,-64.4 -64.68,-64.4 -64.62,-64.4 -64.56,-64.4 -64.5,-64.4 -64.44,-64.4 -64.38,-64.4 -64.32,-64.4 -64.26,-64.4 -64.2))", "dataset_titles": "Dataset: Particulate Organic Carbon and Particulate Nitrogen; Dataset: Photosynthetic Pigments; Dataset: Physical Profiles of Temperature, Salinity, and Brine Volume; Sea-ice diatom compatible solute shifts", "datasets": [{"dataset_uid": "200378", "doi": "10.26008/1912/bco-dmo.913655.1", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Dataset: Physical Profiles of Temperature, Salinity, and Brine Volume", "url": "https://www.bco-dmo.org/dataset/913655"}, {"dataset_uid": "200376", "doi": "10.26008/1912/bco-dmo.913566.1", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Dataset: Particulate Organic Carbon and Particulate Nitrogen", "url": "https://www.bco-dmo.org/dataset/913566"}, {"dataset_uid": "200377", "doi": "10.26008/1912/bco-dmo.913222.1", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Dataset: Photosynthetic Pigments", "url": "https://www.bco-dmo.org/dataset/913222"}, {"dataset_uid": "200322", "doi": "10.21228/M84386", "keywords": null, "people": null, "repository": "Metabolomics workbench", "science_program": null, "title": "Sea-ice diatom compatible solute shifts", "url": "https://www.metabolomicsworkbench.org/data/DRCCMetadata.php?Mode=Study\u0026StudyID=ST001393"}], "date_created": "Tue, 23 Jul 2019 00:00:00 GMT", "description": "Rapid changes in the extent and thickness of sea ice during the austral spring subject microorganisms within or attached to the ice to large fluctuations in temperature, salinity, light and nutrients. This project aims to identify cellular responses in sea-ice algae to increasing temperature and decreasing salinity during the spring melt along the western Antarctic Peninsula and to determine how associated changes at the cellular level can potentially affect dynamic, biologically driven processes. Understanding how sea-ice algae cope with, and are adapted to, their environment will not only help predict how polar ecosystems may change as the extent and thickness of sea ice change, but will also provide a better understanding of the widespread success of photosynthetic life on Earth. The scientific context and resulting advances from the research will be communicated to the general public through outreach activities that includes work with Science Communication Fellows and the popular Polar Science Weekend at the Pacific Science Center in Seattle, Washington. The project will provide student training to college students as well as provide for educational experiences for K-12 school children. \u003cbr/\u003e\u003cbr/\u003e\u003cbr/\u003eThere is currently a poor understanding of feedback relationships that exist between the rapidly changing environment in the western Antarctic Peninsula region and sea-ice algal production. The large shifts in temperature and salinity that algae experience during the spring melt affect critical cellular processes, including rates of enzyme-catalyzed reactions involved in photosynthesis and respiration, and the production of stress-protective compounds. These changes in cellular processes are poorly constrained but can be large and may have impacts on local ecosystem productivity and biogeochemical cycles. In particular, this study will focus on the thermal sensitivity of enzymes and the cycling of compatible solutes and exopolymers used for halo- and cryo-protection, and how they influence primary production and the biogeochemical cycling of carbon and nitrogen. Approaches will include field sampling during spring melt, incubation experiments of natural sea-ice communities under variable temperature and salinity conditions, and controlled manipulation of sea-ice algal species in laboratory culture. Employment of a range of techniques, from fast repetition rate fluorometry and gross and net photosynthetic measurements to metabolomics and enzyme kinetics, will tease apart the mechanistic effects of temperature and salinity on cell metabolism and primary production with the goal of quantifying how these changes will impact biogeochemical processes along the western Antarctic Peninsula.\u003cbr/\u003e\u003cbr/\u003eThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -64.2, "geometry": "POINT(-64.3 -64.5)", "instruments": null, "is_usap_dc": true, "keywords": "USAP-DC; SHIPS; DIATOMS; Antarctic Peninsula", "locations": "Antarctic Peninsula", "north": -64.2, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Young, Jodi; Deming, Jody", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e SHIPS", "repo": "BCO-DMO", "repositories": "BCO-DMO; Metabolomics workbench", "science_programs": null, "south": -64.8, "title": "Spring Blooms of Sea Ice Algae Along the Western Antarctic Peninsula: Effects of Warming and Freshening on Cell Physiology and Biogeochemical Cycles.", "uid": "p0010039", "west": -64.4}, {"awards": "1745036 Marchetti, Adrian; 1744760 Hopkinson, Brian", "bounds_geometry": "POLYGON((-77 -61,-75.2 -61,-73.4 -61,-71.6 -61,-69.8 -61,-68 -61,-66.2 -61,-64.4 -61,-62.6 -61,-60.8 -61,-59 -61,-59 -62.1,-59 -63.2,-59 -64.3,-59 -65.4,-59 -66.5,-59 -67.6,-59 -68.7,-59 -69.8,-59 -70.9,-59 -72,-60.8 -72,-62.6 -72,-64.4 -72,-66.2 -72,-68 -72,-69.8 -72,-71.6 -72,-73.4 -72,-75.2 -72,-77 -72,-77 -70.9,-77 -69.8,-77 -68.7,-77 -67.6,-77 -66.5,-77 -65.4,-77 -64.3,-77 -63.2,-77 -62.1,-77 -61))", "dataset_titles": "Photosynthetic physiological data of Proteorhodopsin containing diatoms under differing iron availabilities", "datasets": [{"dataset_uid": "601530", "doi": "10.15784/601530", "keywords": "Antarctica; Diatom", "people": "Andrew, Sarah; Hopkinson, Brian; Plumb, Kaylie; Marchetti, Adrian", "repository": "USAP-DC", "science_program": null, "title": "Photosynthetic physiological data of Proteorhodopsin containing diatoms under differing iron availabilities", "url": "https://www.usap-dc.org/view/dataset/601530"}], "date_created": "Sun, 16 Jun 2019 00:00:00 GMT", "description": "Proteorhodopsins (PR) are retinal-binding membrane proteins that can act as light-driven proton pumps to generate energy that can be used for metabolism and growth. The discovery of PRs in many diverse marine prokaryotic microbes has initiated extensive investigations into their distributions and functional roles. Recently, a rhodopsin-like gene of the proton-pumping variety was identified in diatoms thus revealing their presence within obligate marine eukaryotic photoautotrophs. Since this time, PRs have been identified in a number of diatom isolates although there appears to be a much higher frequency of\r\nPR in diatoms residing in cold, iron-limited regions of the ocean, particularly in the Southern Ocean (SO). PR is especially suited for use in SO phytoplankton since unlike conventional photosynthesis, it uses no iron and its reaction rate is insensitive to temperature. The overall objective of our proposed project is to characterize Antarctic diatom-PR and determine its role in the adaptation of SO diatoms to the prevailing conditions of low iron concentrations and extremely low temperatures. Our research objectives will be achieved through a combination of molecular, biochemical and physiological measurements in diatom isolates recently obtained from the Western Antarctic Peninsula region. We will determine the proton-pumping characteristics and pumping rates of PR as a function of light intensity and wavelength, the resultant PR-linked intracellular ATP production rates, and the cellular localization of the protein. We will examine under which environmental conditions Antarctic diatom-PR is most highly expressed and construct a cellular energy budget that includes diatom-PR when grown under these different growth conditions. Estimates of the energy flux generated by PR in PR-containing diatoms will be compared to total energy generation by the photosynthetic light reactions and metabolically coupled respiration rates. Finally, we will compare the characteristics and gene expression of diatom-PR in Antarctic diatoms to PR-containing diatoms isolated from temperate regions in order to investigate if there is a preferential dependence on energy production through diatom-PR in diatoms residing in cold, iron-limited regions of the ocean.", "east": -59.0, "geometry": "POINT(-68 -66.5)", "instruments": null, "is_usap_dc": true, "keywords": "FIELD INVESTIGATION; NSF/USA; Southern Ocean; AMD; Amd/Us; LABORATORY; USAP-DC; BIOGEOCHEMICAL CYCLES", "locations": "Southern Ocean", "north": -61.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Marchetti, Adrian; Septer, Alecia; Hopkinson, Brian", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -72.0, "title": "Collaborative research: Antarctic diatom proteorhodopsins: Characterization and a potential role in the iron-limitation response", "uid": "p0010033", "west": -77.0}, {"awards": "1246292 Cary, Stephen", "bounds_geometry": "POLYGON((161.36062 -77.20215,161.610171 -77.20215,161.859722 -77.20215,162.109273 -77.20215,162.358824 -77.20215,162.608375 -77.20215,162.857926 -77.20215,163.107477 -77.20215,163.357028 -77.20215,163.606579 -77.20215,163.85613 -77.20215,163.85613 -77.291278,163.85613 -77.380406,163.85613 -77.469534,163.85613 -77.558662,163.85613 -77.64779,163.85613 -77.736918,163.85613 -77.826046,163.85613 -77.915174,163.85613 -78.004302,163.85613 -78.09343,163.606579 -78.09343,163.357028 -78.09343,163.107477 -78.09343,162.857926 -78.09343,162.608375 -78.09343,162.358824 -78.09343,162.109273 -78.09343,161.859722 -78.09343,161.610171 -78.09343,161.36062 -78.09343,161.36062 -78.004302,161.36062 -77.915174,161.36062 -77.826046,161.36062 -77.736918,161.36062 -77.64779,161.36062 -77.558662,161.36062 -77.469534,161.36062 -77.380406,161.36062 -77.291278,161.36062 -77.20215))", "dataset_titles": "Carbon-fixation rates and associated microbial communities; Carbon-fixation rates and associated microbial communities residing in arid and ephemerally wet Antarctic Dry Valley soils; Importance of Heterotrophic and Phototrophic N2 Fixation in the McMurdo Dry Valleys ; Microbial community composition of transiently wetted Antarctic Dry Valley soils.; Microbial population dynamics along a terrestrial Antarctic moisture gradient; Microbial population dynamics along a terrestrial wetted gradient", "datasets": [{"dataset_uid": "200015", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Microbial community composition of transiently wetted Antarctic Dry Valley soils.", "url": "https://www.ncbi.nlm.nih.gov/popset/?term=KP836071%20to%20KP836108"}, {"dataset_uid": "200014", "doi": "", "keywords": null, "people": null, "repository": "EMBL", "science_program": null, "title": "Microbial population dynamics along a terrestrial wetted gradient", "url": "https://www.ebi.ac.uk/ena/data/view/PRJEB7939"}, {"dataset_uid": "002737", "doi": "", "keywords": null, "people": null, "repository": "KNB", "science_program": null, "title": "Carbon-fixation rates and associated microbial communities residing in arid and ephemerally wet Antarctic Dry Valley soils", "url": "https://knb.ecoinformatics.org/view/knb.756.1"}, {"dataset_uid": "002738", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Carbon-fixation rates and associated microbial communities", "url": "https://www.ncbi.nlm.nih.gov/protein/?term=craig%20cary"}, {"dataset_uid": "200013", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Importance of Heterotrophic and Phototrophic N2 Fixation in the McMurdo Dry Valleys ", "url": "https://www.ncbi.nlm.nih.gov/bioproject/?term=PRJNA505820"}, {"dataset_uid": "002736", "doi": "", "keywords": null, "people": null, "repository": "EMBL", "science_program": null, "title": "Microbial population dynamics along a terrestrial Antarctic moisture gradient", "url": "https://www.ebi.ac.uk/ena/data/view/PRJEB27415"}], "date_created": "Wed, 14 Mar 2018 00:00:00 GMT", "description": "The McMurdo Dry Valleys in Antarctica are recognized as being the driest, coldest and probably one of the harshest environments on Earth. In addition to the lack of water, the biota in the valleys face a very limited supply of nutrients such as nitrogen compounds - necessary for protein synthesis. The glacial streams of the Dry Valleys have extensive cyanobacterial (blue green algae) mats that are a major source of carbon and nitrogen compounds to biota in this region. While cyanobacteria in streams are important as a source of these compounds, other non-photosynthetic bacteria also contribute a significant fraction (~50%) of fixed nitrogen compounds to valley biota. This research effort will involve an examination of exactly which non-phototrophic bacteria are involved in nitrogen fixation and what environmental factors are responsible for controlling nitrogen fixation by these microbes. This work will resolve the environmental factors that control the activity, abundance and diversity of nitrogen-fixing microbes across four of the McMurdo Dry Valleys. This will allow for comparisons among sites of differing latitude, temperature, elevation and exposure to water. These results will be integrated into a landscape wetness model that will help determine the impact of both cyanobacterial and non-photosynthetic nitrogen fixing microorganisms in this very harsh environment.\u003cbr/\u003e\u003cbr/\u003eThe Dry Valleys in many ways resemble the Martian environment, and understanding the primitive life and very simple nutrient cycling in the Dry Valleys has relevance for understanding how life might have once existed on other planets. Furthermore, the study of microbes from extreme environments has resulted in numerous biotechnological applications such as the polymerase chain reaction for amplifying DNA and mechanisms for freeze resistance in agricultural crops. Thus, this research should yield insights into how biota survive in extreme environments, and these insights could lead to other commercial applications.", "east": 163.85613, "geometry": "POINT(162.608375 -77.64779)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; Antarctica; USAP-DC; RIVERS/STREAM", "locations": "Antarctica", "north": -77.20215, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Cary, Stephen", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "NCBI GenBank", "repositories": "EMBL; KNB; NCBI GenBank", "science_programs": null, "south": -78.09343, "title": "Collaborative Research: Importance of Heterotrophic and Phototrophic N2 Fixation in the McMurdo Dry Valleys on Local, Regional and Landscape Scales", "uid": "p0000235", "west": 161.36062}, {"awards": "1056396 Morgan-Kiss, Rachael", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Genetic sequence identifier: Accession Numbers: GU132860-GU132939; JN091926-JN091960; JQ9243533-JQ924384; KJ848331-KJ848439; KU196097-KU196166; PRJNA396917", "datasets": [{"dataset_uid": "000241", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Genetic sequence identifier: Accession Numbers: GU132860-GU132939; JN091926-JN091960; JQ9243533-JQ924384; KJ848331-KJ848439; KU196097-KU196166; PRJNA396917", "url": "https://www.ncbi.nlm.nih.gov/genbank/"}], "date_created": "Mon, 26 Feb 2018 00:00:00 GMT", "description": "This CAREER proposal will support an early career female PI to establish an integrated research and education program in the fields of polar biology and environmental microbiology, focusing on single-celled eukaryotes (protists) in high latitude ice-covered Antarctic lakes systems. Protists play important roles in energy flow and material cycling, and act as both primary producers (fixing inorganic carbon by photosynthesis) and consumers (preying on bacteria by phagotrophic digestion). The McMurdo Dry Valleys (MDV) located in Victoria Land, Antarctica, harbor microbial communities which are isolated in the unique aquatic ecosystem of perennially ice-capped lakes. The lakes support exclusively microbial consortia in chemically stratified water columns that are not influenced by seasonal mixing, allochthonous inputs, or direct human impact. This project will exploit permanently stratified biogeochemistry that is unique across the water columns of several MDV lakes to address gaps in our understanding of protist trophic function in aquatic food webs. The proposed research will examine (1) the impact of permanent biogeochemical gradients on protist trophic strategy, (2) the effect of major abiotic drivers (light and nutrients) on the distribution of two key mixotrophic and photoautotrophic protist species, and (3) the effect of episodic nutrient pulses on mixotroph communities in high latitude (ultraoligotrophic) MDV lakes versus low latitude (eutrophic) watersheds. The project will impact the fields of microbial ecology and environmental microbiology by combining results from field, laboratory and in situ incubation studies to synthesize new models for the protist trophic roles in the aquatic food web. The research component of this proposed project will be tightly integrated with the development of two new education activities designed to exploit the inherent excitement associated with polar biological research. The educational objectives are: 1) to establish a teaching module in polar biology in a core undergraduate course for microbiology majors; 2) to develop an instructional module to engage middle school girls in STEM disciplines. Undergraduates and middle school girls will also work with a doctoral student on his experiments in local Ohio watersheds.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; USAP-DC", "locations": null, "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Morgan-Kiss, Rachael", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "NCBI GenBank", "repositories": "NCBI GenBank", "science_programs": null, "south": -90.0, "title": "CAREER:Protist Nutritional Strategies in Permanently Stratified Antarctic Lakes", "uid": "p0000310", "west": -180.0}, {"awards": "1341362 Gast, Rebecca", "bounds_geometry": "POLYGON((-180 -65,-176 -65,-172 -65,-168 -65,-164 -65,-160 -65,-156 -65,-152 -65,-148 -65,-144 -65,-140 -65,-140 -66.5,-140 -68,-140 -69.5,-140 -71,-140 -72.5,-140 -74,-140 -75.5,-140 -77,-140 -78.5,-140 -80,-144 -80,-148 -80,-152 -80,-156 -80,-160 -80,-164 -80,-168 -80,-172 -80,-176 -80,180 -80,178 -80,176 -80,174 -80,172 -80,170 -80,168 -80,166 -80,164 -80,162 -80,160 -80,160 -78.5,160 -77,160 -75.5,160 -74,160 -72.5,160 -71,160 -69.5,160 -68,160 -66.5,160 -65,162 -65,164 -65,166 -65,168 -65,170 -65,172 -65,174 -65,176 -65,178 -65,-180 -65))", "dataset_titles": "Dinoflagellate sequende data", "datasets": [{"dataset_uid": "000240", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Dinoflagellate sequende data", "url": "http://www.ncbi.nlm.nih.gov/bioproject/428208"}], "date_created": "Mon, 12 Feb 2018 00:00:00 GMT", "description": "Kleptoplasty, the temporary acquisition and use of functional chloroplasts derived from algal prey, is viewed as an important model for the early evolution of the permanent, endosymbiotically-derived chloroplasts found in all permanently photosynthetic eukaryotes. This project will study the evolutionary history and expression of plastid-targeted genes in an abundant Antarctic dinoflagellate that steals chloroplasts from an ecologically important alga, the haptophyte Phaeocystis. Algae play an important role in the fixation and export of CO2 in the Southern Ocean, and this project will explore the genetic basis for the function of these chimeric cells with regard to their functional adaptation to extreme environments and will study the evolutionary history and expression of plastid-targeted genes in both the host and recipient. The project seeks to determine whether the kleptoplastidic dinoflagellate utilizes ancestral plastid proteins to regulate its stolen plastid, and how their transcription is related to environmental factors that are relevant to the Southern Ocean environment (temperature and light). To accomplish these goals, the project will utilize high throughput transcriptome analysis and RNA-sequencing experiments with the dinoflagellate and Phaeocystis. \u003cbr/\u003e\u003cbr/\u003eThis work will help biologists understand the environmental success of this alternative nutritional strategy, and to assess the potential impact of anthropogenic climate change on the organism. The project will also contribute to the maintenance of a culture collection of heterotrophic, phototrophic and mixotrophic Antarctic protists that are available to the scientific community, and it will support the mentoring of a graduate student and a postdoctoral fellow. The work is being accomplished as an international collaboration between US and Canadian scientists, and in addition to publishing results in peer-reviewed journals, the investigators will incorporate aspects of this work into public outreach activities. These include field data analysis opportunities for middle school students and science-based art projects with local schools and museums.", "east": -140.0, "geometry": "POINT(-170 -72.5)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; USAP-DC", "locations": null, "north": -65.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Gast, Rebecca", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "NCBI GenBank", "repositories": "NCBI GenBank", "science_programs": null, "south": -80.0, "title": "You are what you eat: The Role of Kleptoplasty in an Antarctic Dinoflagellate", "uid": "p0000302", "west": 160.0}, {"awards": "1430550 Domack, Eugene; 1143834 Huber, Bruce; 1143833 Orsi, Alejandro; 1143836 Leventer, Amy", "bounds_geometry": "POLYGON((116 -65.2,116.5 -65.2,117 -65.2,117.5 -65.2,118 -65.2,118.5 -65.2,119 -65.2,119.5 -65.2,120 -65.2,120.5 -65.2,121 -65.2,121 -65.38,121 -65.56,121 -65.74,121 -65.92,121 -66.1,121 -66.28,121 -66.46,121 -66.64,121 -66.82,121 -67,120.5 -67,120 -67,119.5 -67,119 -67,118.5 -67,118 -67,117.5 -67,117 -67,116.5 -67,116 -67,116 -66.82,116 -66.64,116 -66.46,116 -66.28,116 -66.1,116 -65.92,116 -65.74,116 -65.56,116 -65.38,116 -65.2))", "dataset_titles": "AU1402 Final UCTD data; AU1402 mooring data; Bottom photos from the Southern Ocean acquired during R/V Nathaniel B. Palmer expedition NBP1402 ; NBP1402 diatom data; NBP1402 Final CTD data; NBP1402 Final UCTD data; NBP1402 JPC43 Diatom Data; NBP14-02 JPC-54 and JPC-55 Pollen Assemblage data; NBP14-02 JPC-55 Bulk Sediment Carbon and Nitrogen data; NBP14-02 JPC-55 foraminifer assemblage data; NBP1402 Lowered ADCP data; Near-bottom Videos from the Southern Ocean acquired during R/V Nathaniel B. Palmer expedition NBP1402; Sabrina Coast mooring data - sediment trap mooring 2014", "datasets": [{"dataset_uid": "601148", "doi": "10.15784/601148", "keywords": "Antarctica; Au1402; Mooring; NBP1402; Oceans; Ocean Temperature; Physical Oceanography; R/v Aurora Australis; R/v Nathaniel B. Palmer; Sabrina Coast; Salinity; Southern Ocean; Temperature", "people": "Orsi, Alejandro", "repository": "USAP-DC", "science_program": null, "title": "AU1402 mooring data", "url": "https://www.usap-dc.org/view/dataset/601148"}, {"dataset_uid": "601068", "doi": "10.15784/601068", "keywords": "ADCP Acoustic Doppler Current Profiler; Antarctica; NBP1402; Oceans; Physical Oceanography; Sabrina Coast; Sample/collection Description; Sample/Collection Description; Southern Ocean", "people": "Huber, Bruce", "repository": "USAP-DC", "science_program": null, "title": "NBP1402 Lowered ADCP data", "url": "https://www.usap-dc.org/view/dataset/601068"}, {"dataset_uid": "601067", "doi": "10.15784/601067", "keywords": "Antarctica; CTD Data; NBP1402; Oceans; Physical Oceanography; Sabrina Coast; Sample/collection Description; Sample/Collection Description; Southern Ocean", "people": "Huber, Bruce", "repository": "USAP-DC", "science_program": null, "title": "NBP1402 Final CTD data", "url": "https://www.usap-dc.org/view/dataset/601067"}, {"dataset_uid": "601046", "doi": "10.15784/601046", "keywords": "Antarctica; Biota; Marine Sediments; NBP1402; Oceans; Paleoclimate; Pollen; Sabrina Coast; Sediment Core; Southern Ocean; Totten Glacier", "people": "Domack, Eugene Walter; Shevenell, Amelia; Smith, Catherine", "repository": "USAP-DC", "science_program": null, "title": "NBP14-02 JPC-54 and JPC-55 Pollen Assemblage data", "url": "https://www.usap-dc.org/view/dataset/601046"}, {"dataset_uid": "601440", "doi": "10.15784/601440", "keywords": "Antarctica; Diatom; Holocene; Jumbo Piston Corer; NBP1402; R/v Nathaniel B. Palmer; Sabrina Coast; Sediment Core Data; Species Abundance; Totten Glacier", "people": "Leventer, Amy", "repository": "USAP-DC", "science_program": null, "title": "NBP1402 JPC43 Diatom Data", "url": "https://www.usap-dc.org/view/dataset/601440"}, {"dataset_uid": "601044", "doi": "10.15784/601044", "keywords": "Antarctica; Carbon; Chemistry:sediment; Chemistry:Sediment; Geochemistry; Marine Sediments; NBP1402; Nitrogen; Oceans; Sabrina Coast; Sediment Core; Southern Ocean; Totten Glacier", "people": "Shevenell, Amelia; Smith, Catherine; Domack, Eugene Walter", "repository": "USAP-DC", "science_program": null, "title": "NBP14-02 JPC-55 Bulk Sediment Carbon and Nitrogen data", "url": "https://www.usap-dc.org/view/dataset/601044"}, {"dataset_uid": "601312", "doi": null, "keywords": "Antarctica; Benthic Images; Camera; East Antarctica; Marine Geoscience; NBP1402; Photo/video; Photo/Video; R/v Nathaniel B. Palmer; Sabrina Coast; Totten Glacier; Video Data; Yoyo Camera", "people": "Shevenell, Amelia; Orsi, Alejandro; Huber, Bruce; Gulick, Sean; Domack, Eugene Walter; Blankenship, Donald D.; Post, Alexandra; Leventer, Amy", "repository": "USAP-DC", "science_program": null, "title": "Near-bottom Videos from the Southern Ocean acquired during R/V Nathaniel B. Palmer expedition NBP1402", "url": "https://www.usap-dc.org/view/dataset/601312"}, {"dataset_uid": "601310", "doi": null, "keywords": "Antarctica; Benthic Images; Benthos; East Antarctica; Marine Geoscience; NBP1402; Photo; Photo/video; Photo/Video; R/v Nathaniel B. Palmer; Totten Glacier; Yoyo Camera", "people": "Gulick, Sean; Domack, Eugene Walter; Post, Alexandra; Leventer, Amy; Shevenell, Amelia; Huber, Bruce; Orsi, Alejandro", "repository": "USAP-DC", "science_program": null, "title": "Bottom photos from the Southern Ocean acquired during R/V Nathaniel B. Palmer expedition NBP1402 ", "url": "https://www.usap-dc.org/view/dataset/601310"}, {"dataset_uid": "601258", "doi": "10.15784/601258", "keywords": "Antarctica; Diatom; NBP1402; Totten Glacier", "people": "NBP1402 science party; Leventer, Amy", "repository": "USAP-DC", "science_program": null, "title": "NBP1402 diatom data", "url": "https://www.usap-dc.org/view/dataset/601258"}, {"dataset_uid": "601146", "doi": "10.15784/601146", "keywords": "Antarctica; CTD Data; NBP1402; Oceans; Ocean Temperature; Physical Oceanography; R/v Nathaniel B. Palmer; Sabrina Coast; Salinity; Southern Ocean; Temperature", "people": "Orsi, Alejandro", "repository": "USAP-DC", "science_program": null, "title": "NBP1402 Final UCTD data", "url": "https://www.usap-dc.org/view/dataset/601146"}, {"dataset_uid": "601147", "doi": "10.15784/601147", "keywords": "Antarctica; CTD Data; NBP1402; Ocean Temperature; Physical Oceanography; Sabrina Coast; Salinity; Southern Ocean; Temperature; Underway CTD", "people": "Orsi, Alejandro", "repository": "USAP-DC", "science_program": null, "title": "AU1402 Final UCTD data", "url": "https://www.usap-dc.org/view/dataset/601147"}, {"dataset_uid": "601042", "doi": "10.15784/601042", "keywords": "Antarctica; Biota; Continental Margin; Foraminifera; NBP1402; Oceans; Paleoclimate; Sabrina Coast; Sample/collection Description; Sample/Collection Description; Southern Ocean; Totten Glacier", "people": "Shevenell, Amelia; Leventer, Amy", "repository": "USAP-DC", "science_program": null, "title": "NBP14-02 JPC-55 foraminifer assemblage data", "url": "https://www.usap-dc.org/view/dataset/601042"}, {"dataset_uid": "601069", "doi": "10.15784/601069", "keywords": "Antarctica; Mooring; NBP1402; Oceans; Physical Oceanography; Sabrina Coast; Sample/collection Description; Sample/Collection Description; Southern Ocean", "people": "Huber, Bruce", "repository": "USAP-DC", "science_program": null, "title": "Sabrina Coast mooring data - sediment trap mooring 2014", "url": "https://www.usap-dc.org/view/dataset/601069"}], "date_created": "Fri, 26 Jan 2018 00:00:00 GMT", "description": "This project will investigate the marine component of the Totten Glacier and Moscow University Ice Shelf, East Antarctica. This system is of critical importance because it drains one-eighth of the East Antarctic Ice Sheet and contains a volume equivalent to nearly 7 meters of potential sea level rise, greater than the entire West Antarctic Ice Sheet. This nearly completely unexplored region is the single largest and least understood marine glacial system that is potentially unstable. Despite intense scrutiny of marine based systems in the West Antarctic Ice Sheet, little is known about the Totten Glacier system. This study will add substantially to the meager oceanographic and marine geology and geophysics data available in this region, and will significantly advance understanding of this poorly understood glacial system and its potentially sensitive response to environmental change.\u003cbr/\u003e\u003cbr/\u003eIndependent, space-based platforms indicate accelerating mass loss of the Totten system. Recent aerogeophysical surveys of the Aurora Subglacial Basin, which contains the deepest ice in Antarctica and drains into the Totten system, have provided the subglacial context for measured surface changes and show that the Totten Glacier has been the most significant drainage pathway for at least two previous ice flow regimes. However, the offshore context is far less understood. Limited physical oceanographic data from the nearby shelf/slope break indicate the presence of Modified Circumpolar Deep Water within a thick bottom layer at the mouth of a trough with apparent access to Totten Glacier, suggesting the possibility of sub-glacial bottom inflow of relatively warm water, a process considered to be responsible for West Antarctic Ice Sheet grounding line retreat. This project will conduct a ship-based marine geologic and geophysical survey of the region, combined with a physical oceanographic study, in order to evaluate both the recent and longer-term behavior of the glacial system and its relationship to the adjacent oceanographic system. This endeavor will complement studies of other Antarctic ice shelves, oceanographic studies near the Antarctic Peninsula, and ongoing development of ice sheet and other ocean models.", "east": 121.0, "geometry": "POINT(118.5 -66.1)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD", "is_usap_dc": true, "keywords": "Totten Glacier; NBP1402; Sabrina Coast; LABORATORY; Diatom; R/V NBP; Amd/Us; Bottom Photos; R/V AA; Not provided; USAP-DC; AMD; USA/NSF", "locations": "Sabrina Coast; Totten Glacier", "north": -65.2, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science", "paleo_time": null, "persons": "Orsi, Alejandro; Huber, Bruce; Leventer, Amy; Domack, Eugene Walter", "platforms": "Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V AA; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -67.0, "title": "Collaborative Research: Totten Glacier System and the Marine Record of Cryosphere - Ocean Dynamics", "uid": "p0000008", "west": 116.0}, {"awards": "1443474 Jenkins, Bethany", "bounds_geometry": null, "dataset_titles": "Expedition data of NBP1608", "datasets": [{"dataset_uid": "002664", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP1608", "url": "https://www.rvdata.us/search/cruise/NBP1608"}], "date_created": "Fri, 29 Dec 2017 00:00:00 GMT", "description": "This project focuses on an important group of photosynthetic algae in the Southern Ocean (SO), diatoms, and the roles associated bacterial communities play in modulating their growth. Diatom growth fuels the SO food web and balances atmospheric carbon dioxide by sequestering the carbon used for growth to the deep ocean on long time scales as cells sink below the surface. The diatom growth is limited by the available iron in the seawater, most of which is not freely available to the diatoms but instead is tightly bound to other compounds. The nature of these compounds and how phytoplankton acquire iron from them is critical to understanding productivity in this region and globally. The investigators will conduct experiments to characterize the relationship between diatoms, their associated bacteria, and iron in open ocean and inshore waters. Experiments will involve supplying nutrients at varying nutrient ratios to natural phytoplankton assemblages to determine how diatoms and their associated bacteria respond to different conditions. This will provide valuable data that can be used by climate and food web modelers and it will help us better understand the relationship between iron, a key nutrient in the ocean, and the organisms at the base of the food web that use iron for photosynthetic growth and carbon uptake. The project will also further the NSF goals of training new generations of scientists and of making scientific discoveries available to the general public. The project supports early career senior investigators and the training of graduate and undergraduate students as well as outreach activities with middle school Girl Scouts in Rhode Island, inner city middle and high school age girls in Virginia, and middle school girls in Florida.\u003cbr/\u003e\u003cbr/\u003eThe project combines trace metal biogeochemistry, phytoplankton cultivation, and molecular biology to address questions regarding the production of iron-binding compounds and the role of diatom-bacterial interactions in this iron-limited region. Iron is an essential micronutrient for marine phytoplankton. Phytoplankton growth in the SO is limited by a lack of sufficient iron, with important consequences for carbon cycling and climate in this high latitude regime. Some of the major outstanding questions in iron biogeochemistry relate to the organic compounds that bind \u003e99.9% of dissolved iron in surface oceans. The investigators\u0027 prior research in this region suggests that production of strong iron-binding compounds in the SO is linked to diatom blooms in waters with high nitrate to iron ratios. The sources of these compounds are unknown but the investigators hypothesize that they may be from bacteria, which are known to produce such compounds for their own use. The project will test three hypotheses concerning the production of these iron-binding compounds, limitations on the biological availability of iron even if present in high concentrations, and the roles of diatom-associated bacteria in these processes. Results from this project will provide fundamental information about the biogeochemical trigger, and biological sources and function, of natural strong iron-binding compound production in the SO, where iron plays a critical role in phytoplankton productivity, carbon cycling, and climate regulation.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e FLUOROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e AWS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ECHO SOUNDERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MBES; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e THERMOSALINOGRAPHS", "is_usap_dc": false, "keywords": "R/V NBP; NBP1608", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Jenkins, Bethany", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": null, "title": "Collaborative Research: Investigating Iron-inding Ligands in Southern Ocean Diatom Communities: The Role of Diatom-Bacteria Associations", "uid": "p0000852", "west": null}, {"awards": "1103428 Thurber, Andrew", "bounds_geometry": "POLYGON((165 -77,165.5 -77,166 -77,166.5 -77,167 -77,167.5 -77,168 -77,168.5 -77,169 -77,169.5 -77,170 -77,170 -77.1,170 -77.2,170 -77.3,170 -77.4,170 -77.5,170 -77.6,170 -77.7,170 -77.8,170 -77.9,170 -78,169.5 -78,169 -78,168.5 -78,168 -78,167.5 -78,167 -78,166.5 -78,166 -78,165.5 -78,165 -78,165 -77.9,165 -77.8,165 -77.7,165 -77.6,165 -77.5,165 -77.4,165 -77.3,165 -77.2,165 -77.1,165 -77))", "dataset_titles": "McMurdo Spiophanes beds 16s V4 region community composition from sediment cores at McMurdo Station, Antarctia on Sept 9th, 2012 (McMurdo Benthos project); Stable isotopic composition of McMurdo Benthos", "datasets": [{"dataset_uid": "000201", "doi": "", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Stable isotopic composition of McMurdo Benthos", "url": "https://www.bco-dmo.org/dataset/716462"}, {"dataset_uid": "000202", "doi": "", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "McMurdo Spiophanes beds 16s V4 region community composition from sediment cores at McMurdo Station, Antarctia on Sept 9th, 2012 (McMurdo Benthos project)", "url": "https://www.bco-dmo.org/dataset/716443"}], "date_created": "Tue, 10 Oct 2017 00:00:00 GMT", "description": "The biota of the world\u0027s seafloor is fueled by bursts of seasonal primary production. For food-limited sediment communities to persist, a balance must exist between metazoan consumption of and competition with bacteria, a balance which likely changes through the seasons. Polar marine ecosystems are ideal places to study such complex interactions due to stark seasonal shifts between heterotrophic and autotrophic communities, and temperatures that may limit microbial processing of organic matter. The research will test the following hypotheses: 1) heterotrophic bacteria compete with macrofauna for food; 2) as phytoplankton populations decline macrofauna increasingly consume microbial biomass to sustain their populations; and 3) in the absence of seasonal photosynthetic inputs, macrofaunal biodiversity will decrease unless supplied with microbially derived nutrition. Observational and empirical studies will test these hypotheses at McMurdo Station, Antarctica, where a high-abundance macro-infaunal community is adapted to this boom-and-bust cycle of productivity. The investigator will mentor undergraduates from a predominantly minority-serving institution, in the fields of invertebrate taxonomy and biogeochemistry. The general public and young scientists will be engaged through lectures at local K-12 venues and launch of an interactive website. The results will better inform scientists and managers about the effects of climate change on polar ecosystems and the mechanisms of changing productivity patterns on global biodiversity.", "east": 170.0, "geometry": "POINT(167.5 -77.5)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -77.0, "nsf_funding_programs": null, "paleo_time": null, "persons": "Thurber, Andrew", "platforms": "Not provided", "repo": "BCO-DMO", "repositories": "BCO-DMO", "science_programs": null, "south": -78.0, "title": "PostDoctoral Research Fellowship", "uid": "p0000416", "west": 165.0}, {"awards": "0944686 Kieber, David; 0944659 Kiene, Ronald", "bounds_geometry": "POLYGON((-180 -68,-177 -68,-174 -68,-171 -68,-168 -68,-165 -68,-162 -68,-159 -68,-156 -68,-153 -68,-150 -68,-150 -69,-150 -70,-150 -71,-150 -72,-150 -73,-150 -74,-150 -75,-150 -76,-150 -77,-150 -78,-153 -78,-156 -78,-159 -78,-162 -78,-165 -78,-168 -78,-171 -78,-174 -78,-177 -78,180 -78,178 -78,176 -78,174 -78,172 -78,170 -78,168 -78,166 -78,164 -78,162 -78,160 -78,160 -77,160 -76,160 -75,160 -74,160 -73,160 -72,160 -71,160 -70,160 -69,160 -68,162 -68,164 -68,166 -68,168 -68,170 -68,172 -68,174 -68,176 -68,178 -68,-180 -68))", "dataset_titles": "Ecophysiology of DMSP and related compounds and their contributions to carbon and sulfur dynamics in Phaeocystis antarctica", "datasets": [{"dataset_uid": "600150", "doi": "10.15784/600150", "keywords": "Antarctica; Biota; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Oceans; Ross Sea", "people": "Kiene, Ronald", "repository": "USAP-DC", "science_program": null, "title": "Ecophysiology of DMSP and related compounds and their contributions to carbon and sulfur dynamics in Phaeocystis antarctica", "url": "https://www.usap-dc.org/view/dataset/600150"}, {"dataset_uid": "600117", "doi": "10.15784/600117", "keywords": "Biota; Ross Sea; Southern Ocean", "people": "Kieber, David John", "repository": "USAP-DC", "science_program": null, "title": "Ecophysiology of DMSP and related compounds and their contributions to carbon and sulfur dynamics in Phaeocystis antarctica", "url": "https://www.usap-dc.org/view/dataset/600117"}], "date_created": "Wed, 16 Dec 2015 00:00:00 GMT", "description": "Spectacular blooms of Phaeocystis antarctica in the Ross Sea, Antarctica are the source of some of the world\u0027s highest concentrations of dimethylsulfoniopropionate (DMSP) and its volatile degradation product, dimethylsulfide (DMS). The flux of DMS from the oceans to the atmosphere in this region and its subsequent gas phase oxidation generates aerosols that have a strong influence on cloud properties and possibly climate. In the oceans, DMS and DMSP are quantitatively significant components of the carbon, sulfur, and energy flows in marine food webs, especially in the Ross Sea. Despite its central role in carbon and sulfur biogeochemistry in the Ross Sea, surprisingly little is known about the physiological functions of DMSP in P. Antarctica. The research will isolate and characterize DMSP lyases from P. antarctica, with the goal of obtaining amino acid and gene sequence information on these important enzymes. The physiological studies will focus on the effects of varying intensities of photosynthetically active radiation, with and without ultraviolet radiation as these are factors that we have found to be important controls on DMSP and DMS dynamics. The research also will examine the effects of prolonged darkness on the dynamics of DMSP and related compounds in P. antarctica, as survival of this species during the dark Antarctic winter and at sub-euphotic depths appears to be an important part of the Phaeocystis? ecology. A unique aspect of this work is the focus on measurements of intracellular MSA, which if detected, would provide strong evidence for in vivo radical scavenging functions for methyl sulfur compounds. The study will advance understanding of what controls DMSP cycling and ultimately DMS emissions from the Ross Sea and also provide information on what makes P. antarctica so successful in this extreme environment. The research will directly benefit and build on several interrelated ocean-atmosphere programs including the International Surface Ocean Lower Atmosphere Study (SOLAS) program. The PIs will participate in several activities involving K-12 education, High School teacher training, public education and podcasting through the auspices of the Dauphin Island Sea Lab Discovery Hall program and SUNY ESF. Two graduate students will be employed full time, and six undergraduates (2 each summer) will be trained as part of this project.", "east": -150.0, "geometry": "POINT(-175 -73)", "instruments": null, "is_usap_dc": true, "keywords": "Amd/Us; Not provided; Ecophysiology; AMD; USAP-DC; FIELD SURVEYS", "locations": null, "north": -68.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Kiene, Ronald; Kieber, David John", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.0, "title": "Collaborative Research: Ecophysiology of DMSP and related compounds and their contributions to carbon and sulfur dynamics in Phaeocystis antarctica", "uid": "p0000085", "west": 160.0}, {"awards": "1043780 Aydin, Murat", "bounds_geometry": null, "dataset_titles": "Ice Core Air Carbonyl Sulfide Measurements - Taylor Dome M3C1 Ice Core; Ultra-trace Measurements in the WAIS Divide 06A Ice Core", "datasets": [{"dataset_uid": "609659", "doi": "10.7265/N5CV4FPK", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; WAIS Divide; WAIS Divide Ice Core", "people": "Aydin, Murat; Saltzman, Eric", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Ultra-trace Measurements in the WAIS Divide 06A Ice Core", "url": "https://www.usap-dc.org/view/dataset/609659"}, {"dataset_uid": "601361", "doi": "10.15784/601361", "keywords": "Antarctica; Carbonyl Sulfide; Trace Gases", "people": "Saltzman, Eric; Aydin, Murat", "repository": "USAP-DC", "science_program": null, "title": "Ice Core Air Carbonyl Sulfide Measurements - Taylor Dome M3C1 Ice Core", "url": "https://www.usap-dc.org/view/dataset/601361"}], "date_created": "Tue, 27 Oct 2015 00:00:00 GMT", "description": "Aydin/1043780\u003cbr/\u003eThis award supports the analysis of the trace gas carbonyl sulfide (COS) in a deep ice core from West Antarctic Ice Sheet Divide (WAIS-D), Antarctica. COS is the most abundant sulfur gas in the troposphere and a precursor of stratospheric sulfate. It has a large terrestrial COS sink that is tightly coupled to the photosynthetic uptake of atmospheric carbon dioxide (CO2). The primary goal of this project is to develop high a resolution Holocene record of COS from the WAIS-D 06A ice core. The main objectives are 1) to assess the natural variability of COS and the extent to which its atmospheric variability was influenced by climate variability, and 2) to examine the relationship between changes in atmospheric COS and CO2. This project also includes low-resolution sampling and analysis of COS from 10,000-30,000 yrs BP, covering the transition from the Last Glacial Maximum into the early Holocene. The goal of this work is to assess the stability of COS in ice core air over long time scales and to establish the COS levels during the last glacial maximum and the magnitude of the change between glacial and interglacial conditions. The results of this work will be disseminated via peer-review publications and will contribute to environmental assessments such as the WMO Stratospheric Ozone Assessment and IPCC Climate Assessment. This project will support a PhD student and undergraduate researcher in the Department of Earth System Science at the University of California, Irvine, and will create summer research opportunities for undergraduates from non-research active Universities.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GAS CHROMATOGRAPHS", "is_usap_dc": true, "keywords": "Ethane; LABORATORY; N-Butane; Carbonyl Sulfide; Propane; Methyl Bromide; Methyl Chloride; Carbon Disulfide", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Glaciology", "paleo_time": null, "persons": "Aydin, Murat; Saltzman, Eric", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": null, "title": "Carbonyl Sulfide Measurements in the Deep West Antarctic Ice Sheet Divide Ice Core", "uid": "p0000055", "west": null}, {"awards": "1043532 Grzymski, Joseph", "bounds_geometry": "POINT(-64 -64.7)", "dataset_titles": "NCBI GenBank Sequences# PRJNA244317, PRJNA242746", "datasets": [{"dataset_uid": "000168", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "NCBI GenBank Sequences# PRJNA244317, PRJNA242746", "url": "http://www.ncbi.nlm.nih.gov/genbank/"}], "date_created": "Mon, 08 Sep 2014 00:00:00 GMT", "description": "The proposed research will investigate the genomic basis of the physiological and ecological transition of Antarctic marine phytoplankton from a cold dark winter to a warmer, brighter spring. During a field season at Palmer Station, functional genomics (using next generation sequencing technology to identify expressed genes) and in situ fluorometry (FRRF) will be integrated with classical ecological methods to investigate photosynthetic adaptation during phytoplankton species succession from late winter into spring. Using large data sets, this project will test whether amino acid usages differ based on expression. The specific objectives are (1) To characterize phytoplankton succession from the winter to spring transition, and (2) To correlate community gene expression profiles to adaptational differences among taxa. Broader impacts include training of a post doctoral researcher and two undergraduate science majors, with efforts to attract students from underrepresented groups. The P.I.s also will prepare presentations for the public, regarding research experiences, research results, and the importance of climate change.", "east": -64.0, "geometry": "POINT(-64 -64.7)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -64.7, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Grzymski, Joseph", "platforms": "Not provided", "repo": "NCBI GenBank", "repositories": "NCBI GenBank", "science_programs": null, "south": -64.7, "title": "Collaborative Research: Functional Genomics and Physiological Ecology of Seasonal Succession in Antarctic Phytoplankton: Adaptations to Light and Temperature", "uid": "p0000462", "west": -64.0}, {"awards": "1019305 Grim, Jeffrey", "bounds_geometry": null, "dataset_titles": "Impact of Rising Oceanic Temperatures on the Embryonic Development of Antarctic Notothenioid Fishes", "datasets": [{"dataset_uid": "600119", "doi": "10.15784/600119", "keywords": "Biota; Fish Logs; LMG1203; LMG1204; LMG1205; Oceans; Pot; Southern Ocean; Trawl", "people": "Grim, Jeffrey", "repository": "USAP-DC", "science_program": null, "title": "Impact of Rising Oceanic Temperatures on the Embryonic Development of Antarctic Notothenioid Fishes", "url": "https://www.usap-dc.org/view/dataset/600119"}], "date_created": "Mon, 10 Feb 2014 00:00:00 GMT", "description": "Survival of Antarctic notothenioid fishes in the context of global climate change will depend upon the impact of rising oceanic temperatures on their embryonic development, yet little is known regarding the molecular mechanisms underlying this complex suite of processes. Many notothenioids are characterized by secondary pelagicism, which enables them to exploit food sources in the water column and is supported in part by skeletal pedomorphism. Here the PI proposes to examine the hypothesis that reactive oxygen species (ROS) regulate notothenioid skeletal pedomorphism. The PI proposes to examine the hypothesis that reactive oxygen species (ROS) regulate notothenioid skeletal pedomorphism. The research objectives are : 1) To quantify and localize ROS production and identify the point(s) of origin of ROS production in embryonic Antarctic fishes that differ in skeletal phenotypes 2) To determine whether the time course of embryogenesis and the extent of osteological development in embryonic Antarctic fishes can be altered by changing the oxidative status of the animal during embryogenesis 3) To evaluate whether transgenic alteration of oxidative status can induce skeletal pedomorphism in a fish model. Broader Impacts will include teaching undergraduate lectures, recruiting undergraduate students to help with lab analyses (and possibly field work), lectures and demonstrations to high school students, and allowing secondary educators access to personal photos and videos of research animals for curriculum development.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Grim, Jeffrey", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "PostDoctoral Research Fellowship", "uid": "p0000482", "west": null}, {"awards": "0739681 Murray, Alison; 0739698 Doran, Peter", "bounds_geometry": "POINT(161.931 -77.3885)", "dataset_titles": "Geochemistry and Microbiology of the Extreme Aquatic Environment in Lake Vida, East Antarctica", "datasets": [{"dataset_uid": "600080", "doi": "10.15784/600080", "keywords": "Antarctica; Biota; Carbon-14; Chemistry:fluid; Chemistry:Fluid; Chemistry:ice; Chemistry:Ice; Dry Valleys; Geochronology; Ice Core Records; Lake Vida; Microbiology", "people": "Murray, Alison", "repository": "USAP-DC", "science_program": null, "title": "Geochemistry and Microbiology of the Extreme Aquatic Environment in Lake Vida, East Antarctica", "url": "https://www.usap-dc.org/view/dataset/600080"}], "date_created": "Thu, 12 Dec 2013 00:00:00 GMT", "description": "Lake Vida is the largest lake of the McMurdo Dry Valleys, with an approximately 20 m ice cover overlaying a brine of unknown depth with at least 7 times seawater salinity and temperatures below -10 degrees C year-round. Samples of brine collected from ice above the main water body contain 1) the highest nitrous oxide levels of any natural water body on Earth, 2) unusual geochemistry including anomalously high ammonia and iron concentrations, 3) high microbial counts with an unusual proportion (99%) of ultramicrobacteria. The microbial community is unique even compared to other Dry Valley Lakes. The research proposes to enter, for the first time the main brine body below the thick ice of Lake Vida and perform in situ measurements, collect samples of the brine column, and collect sediment cores from the lake bottom for detailed geochemical and microbiological analyses. The results will allow the characterization of present and past life in the lake, assessment of modern and past sedimentary processes, and determination of the lake\u0027s history. The research will be conducted by a multidisciplinary team that will uncover the biogeochemical processes associated with a non-photosynthetic microbial community isolated for a significant period of time. This research will address diversity, adaptive mechanisms and evolutionary processes in the context of the physical evolution of the environment of Lake Vida. Results will be widely disseminated through publications, presentations at national and international meetings, through the Subglacial Antarctic Lake Exploration (SALE) web site and the McMurdo LTER web site. The research will support three graduate students and three undergraduate research assistants. The results will be incorporated into a new undergraduate biogeosciences course at the University of Illinois at Chicago which has an extremely diverse student body, dominated by minorities.", "east": 161.931, "geometry": "POINT(161.931 -77.3885)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -77.3885, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Murray, Alison; Doran, Peter", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.3885, "title": "Collaborative Research: Geochemistry and Microbiology of the Extreme Aquatic Environment in Lake Vida, East Antarctica", "uid": "p0000485", "west": 161.931}, {"awards": "0838955 Gast, Rebecca", "bounds_geometry": "POLYGON((71.504166 -76.159164,71.5142214 -76.159164,71.5242768 -76.159164,71.5343322 -76.159164,71.5443876 -76.159164,71.554443 -76.159164,71.5644984 -76.159164,71.5745538 -76.159164,71.5846092 -76.159164,71.5946646 -76.159164,71.60472 -76.159164,71.60472 -76.2018032,71.60472 -76.2444424,71.60472 -76.2870816,71.60472 -76.3297208,71.60472 -76.37236,71.60472 -76.4149992,71.60472 -76.4576384,71.60472 -76.5002776,71.60472 -76.5429168,71.60472 -76.585556,71.5946646 -76.585556,71.5846092 -76.585556,71.5745538 -76.585556,71.5644984 -76.585556,71.554443 -76.585556,71.5443876 -76.585556,71.5343322 -76.585556,71.5242768 -76.585556,71.5142214 -76.585556,71.504166 -76.585556,71.504166 -76.5429168,71.504166 -76.5002776,71.504166 -76.4576384,71.504166 -76.4149992,71.504166 -76.37236,71.504166 -76.3297208,71.504166 -76.2870816,71.504166 -76.2444424,71.504166 -76.2018032,71.504166 -76.159164))", "dataset_titles": "Alternative Nutritional Strategies in Antarctic Protists", "datasets": [{"dataset_uid": "600103", "doi": "10.15784/600103", "keywords": "Biota; Microbiology; NBP0305; NBP0405; NBP0508; NBP1101; Oceans; Southern Ocean", "people": "Gast, Rebecca", "repository": "USAP-DC", "science_program": null, "title": "Alternative Nutritional Strategies in Antarctic Protists", "url": "https://www.usap-dc.org/view/dataset/600103"}], "date_created": "Wed, 30 Oct 2013 00:00:00 GMT", "description": "This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). \u003cbr/\u003e\u003cbr/\u003eMost organisms meet their carbon and energy needs using photosynthesis (phototrophy) or ingestion/assimilation of organic substances (heterotrophy). However, a nutritional strategy that combines phototrophy and heterotrophy - mixotrophy - is geographically and taxonomically widespread in aquatic systems. While the presence of mixotrophs in the Southern Ocean is known only recently, preliminary evidence indicates a significant role in Southern Ocean food webs. Recent work on Southern Ocean dinoflagellate, Kleptodinium, suggests that it sequesters functional chloroplasts of the bloom-forming haptophyte, Phaeocystis antarctica. This dinoflagellate is abundant in the Ross Sea, has been reported elsewhere in the Southern Ocean, and may have a circumpolar distribution. By combining nutritional modes. mixotrophy may offer competitive advantages over pure autotrophs and heterotrophs. \u003cbr/\u003e\u003cbr/\u003eThe goals of this project are to understand the importance of alternative nutritional strategies for Antarctic species that combine phototrophic and phagotrophic processes in the same organism. The research will combine field investigations of plankton and ice communities in the Southern Ocean with laboratory experiments on Kleptodinium and recently identified mixotrophs from our Antarctic culture collections. The research will address: 1) the relative contributions of phototrophy and phagotrophy in Antarctic mixotrophs; 2) the nature of the relationship between Kleptodinium and its kleptoplastids; 3) the distributions and abundances of mixotrophs and Kleptodinium in the Southern Ocean during austral spring/summer; and 4) the impacts of mixotrophs and Kleptodinium on prey populations, the factors influencing these behaviors and the physiological conditions of these groups in their natural environment. The project will contribute to the maintenance of a culture collection of heterotrophic, phototrophic and mixotrophic Antarctic protists that are available to the scientific community, and it will train graduate and undergraduate students at Temple University. Research findings and activities will be summarized for non-scientific audiences through the PIs\u0027 websites and through other public forums, and will involve middle school teachers via collaboration with COSEE-New England.", "east": 71.60472, "geometry": "POINT(71.554443 -76.37236)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -76.159164, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Gast, Rebecca", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -76.585556, "title": "Collaborative Research: Alternative Nutritional Strategies in Antarctic Protists", "uid": "p0000490", "west": 71.504166}, {"awards": "1142963 Warren, Stephen; 0739779 Warren, Stephen", "bounds_geometry": "POLYGON((157 -76,158.1 -76,159.2 -76,160.3 -76,161.4 -76,162.5 -76,163.6 -76,164.7 -76,165.8 -76,166.9 -76,168 -76,168 -76.2,168 -76.4,168 -76.6,168 -76.8,168 -77,168 -77.2,168 -77.4,168 -77.6,168 -77.8,168 -78,166.9 -78,165.8 -78,164.7 -78,163.6 -78,162.5 -78,161.4 -78,160.3 -78,159.2 -78,158.1 -78,157 -78,157 -77.8,157 -77.6,157 -77.4,157 -77.2,157 -77,157 -76.8,157 -76.6,157 -76.4,157 -76.2,157 -76))", "dataset_titles": "Ice on the Oceans of Snowball Earth Project Data", "datasets": [{"dataset_uid": "000183", "doi": "", "keywords": null, "people": null, "repository": "PI website", "science_program": null, "title": "Ice on the Oceans of Snowball Earth Project Data", "url": "https://digital.lib.washington.edu/researchworks/handle/1773/37320"}], "date_created": "Wed, 10 Jul 2013 00:00:00 GMT", "description": "The climatic changes of late Precambrian time, 600-800 million years ago, included episodes of extreme glaciation, during which ice may have covered nearly the entire ocean for several million years, according to the Snowball Earth hypothesis. These episodes would hold an important place in Earth?s evolutionary history; they could have encouraged biodiversity by trapping life forms in small isolated ice-free areas, or they could have caused massive extinctions that cleared the path for new life forms to fill empty niches. What caused the Earth to become iced over, and what later caused the ice to melt? Scientific investigation of these questions will result in greater understanding of the climatic changes that the Earth can experience, and will enable better predictions of future climate. This project involves Antarctic field observations as well as laboratory studies and computer modeling.\u003cbr/\u003e\u003cbr/\u003eThe aim of this project is not to prove or disprove the Snowball Earth hypothesis but rather to quantify processes that are important for simulating snowball events in climate models. The principal goal is to identify the types of ice that would have been present on the frozen ocean, and to determine how much sunlight they would reflect back to space. Reflection of sunlight by bright surfaces of snow and ice is what would maintain the cold climate at low latitudes. The melting of the ocean required buildup of greenhouse gases, but it was probably aided by deposition of desert dust and volcanic ash darkening the snow and ice. With so much ice on the Earth?s surface, even small differences in the amount of light that the ice absorbed or reflected could cause significant changes in climate. The properties of the ice would also determine where, and in what circumstances, photosynthetic life could have survived. Some kinds of ice that are rare on the modern Earth may have been pivotal in allowing the tropical ocean to freeze. The ocean surfaces would have included some ice types that now exist only in Antarctica: bare cold sea ice with precipitated salts, and \"blue ice\" areas of the Transantarctic Mountains that were exposed by sublimation and have not experienced melting. Field expeditions were mounted to examine these ice types, and the data analysis is underway. A third ice type, sea ice with a salt crust, is being studied in a freezer laboratory. Modeling will show how sunlight would interact with ice containing light-absorbing dust and volcanic ash. Aside from its reflection of sunlight, ice on the Snowball ocean would have been thick enough to flow under its own weight, invading all parts of the ocean. Yet evidence for the survival of photosynthetic life indicates that some regions of liquid water were maintained at the ocean surface. One possible refuge for photosynthetic organisms is a bay at the far end of a nearly enclosed tropical sea, formed by continental rifting and surrounded by desert, such as the modern Red Sea. A model of glacier flow is being developed to determine the dimensions of the channel, connecting the sea to the ocean, necessary to prevent invasion by the flowing ice yet maintain a water supply to replenish evaporation.", "east": 168.0, "geometry": "POINT(162.5 -77)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -76.0, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Integrated System Science", "paleo_time": null, "persons": "Warren, Stephen; Light, Bonnie; Campbell, Adam; Carns, Regina; Dadic, Ruzica; Mullen, Peter; Brandt, Richard; Waddington, Edwin D.", "platforms": "Not provided", "repo": "PI website", "repositories": "PI website", "science_programs": null, "south": -78.0, "title": "Ocean Surfaces on Snowball Earth", "uid": "p0000402", "west": 157.0}, {"awards": "1043564 Karentz, Deneb", "bounds_geometry": null, "dataset_titles": "Expedition data of LMG1106A", "datasets": [{"dataset_uid": "002686", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG1106A", "url": "https://www.rvdata.us/search/cruise/LMG1106A"}], "date_created": "Tue, 17 Jan 2012 00:00:00 GMT", "description": "The proposed research will investigate the genomic basis of the physiological and ecological transition of Antarctic marine phytoplankton from a cold dark winter to a warmer, brighter spring. During a field season at Palmer Station, functional genomics (using next generation sequencing technology to identify expressed genes) and in situ fluorometry (FRRF) will be integrated with classical ecological methods to investigate photosynthetic adaptation during phytoplankton species succession from late winter into spring. Using large data sets, this project will test whether amino acid usages differ based on expression. The specific objectives are (1) To characterize phytoplankton succession from the winter to spring transition, and (2) To correlate community gene expression profiles to adaptational differences among taxa. Broader impacts include training of a post doctoral researcher and two undergraduate science majors, with efforts to attract students from underrepresented groups. The P.I.s also will prepare presentations for the public, regarding research experiences, research results, and the importance of climate change.", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS", "is_usap_dc": false, "keywords": "R/V LMG", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Karentz, Deneb", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": null, "title": "Collaborative Research: Functional Genomics and Physiological Ecology of Seasonal Succession in Antarctic Phytoplankton: Adaptations to Light and Temperature", "uid": "p0000861", "west": null}, {"awards": "0529087 Ross, Robin; 0529666 Fritsen, Christian; 0528728 Vernet, Maria", "bounds_geometry": "POLYGON((-69.08 -64.8,-68.632 -64.8,-68.184 -64.8,-67.736 -64.8,-67.288 -64.8,-66.84 -64.8,-66.392 -64.8,-65.944 -64.8,-65.496 -64.8,-65.048 -64.8,-64.6 -64.8,-64.6 -65.121,-64.6 -65.442,-64.6 -65.763,-64.6 -66.084,-64.6 -66.405,-64.6 -66.726,-64.6 -67.047,-64.6 -67.368,-64.6 -67.689,-64.6 -68.01,-65.048 -68.01,-65.496 -68.01,-65.944 -68.01,-66.392 -68.01,-66.84 -68.01,-67.288 -68.01,-67.736 -68.01,-68.184 -68.01,-68.632 -68.01,-69.08 -68.01,-69.08 -67.689,-69.08 -67.368,-69.08 -67.047,-69.08 -66.726,-69.08 -66.405,-69.08 -66.084,-69.08 -65.763,-69.08 -65.442,-69.08 -65.121,-69.08 -64.8))", "dataset_titles": "Expedition data of NBP0103; The Dynamic Coupling among Phytoplankton, Ice, Ice Algae and Krill (PIIAK)", "datasets": [{"dataset_uid": "600050", "doi": "10.15784/600050", "keywords": "Bellingshausen Sea; Cryosphere; Oceans; Photosynthetically Active Radiation (par); Sea Ice; Sea Surface; Southern Ocean; Total Integrated Exposure To PAR", "people": "Fritsen, Christian", "repository": "USAP-DC", "science_program": null, "title": "The Dynamic Coupling among Phytoplankton, Ice, Ice Algae and Krill (PIIAK)", "url": "https://www.usap-dc.org/view/dataset/600050"}, {"dataset_uid": "600049", "doi": "10.15784/600049", "keywords": "Bellingshausen Sea; Biota; Oceans; Southern Ocean", "people": "Quetin, Langdon B.; Ross, Robin Macurda", "repository": "USAP-DC", "science_program": null, "title": "The Dynamic Coupling among Phytoplankton, Ice, Ice Algae and Krill (PIIAK)", "url": "https://www.usap-dc.org/view/dataset/600049"}, {"dataset_uid": "002595", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0103", "url": "https://www.rvdata.us/search/cruise/NBP0103"}, {"dataset_uid": "600048", "doi": "10.15784/600048", "keywords": "Bellingshausen Sea; Biota; Oceans; Phytoplankton; Southern Ocean", "people": "Vernet, Maria", "repository": "USAP-DC", "science_program": null, "title": "The Dynamic Coupling among Phytoplankton, Ice, Ice Algae and Krill (PIIAK)", "url": "https://www.usap-dc.org/view/dataset/600048"}], "date_created": "Sat, 02 Apr 2011 00:00:00 GMT", "description": "This collaborative study between the Desert Research Institute, the University of California, Santa Barbara (0529087; Robin Ross), and the University of California, San Diego (0528728; Maria Vernet) will examine the relationship between sea ice extent along the Antarctic Peninsula and the life history of krill (Euphausia superba), by developing, refining, and linking diagnostic datasets and models of phytoplankton decreases in the fall, phytoplankton biomass incorporation into sea ice, sea ice growth dynamics, sea ice algal production and biomass accumulation, and larval krill energetics, condition, and survival. Krill is a key species in the food web of the Southern Ocean ecosystem, and one that is intricately involved with seasonal sea ice dynamics. Results from the Southern Ocean experiment of the Global Ocean Ecosystems Dynamics program (SO-Globec) field work as well as historical information on sea ice dynamics and krill recruitment suggest a shift in the paradigm that all pack ice is equally good krill habitat.\u003cbr/\u003e\u003cbr/\u003eSO-Globec is a multidisciplinary effort focused on understanding the physical and biological factors that influence growth, reproduction, recruitment and survival of Antarctic krill (Euphausia superba). The program uses a multi-trophic level approach that includes the predators and competitors of Antarctic krill, represented by other zooplankton, fish, penguins, seals, and cetaceans. It is currently in a synthesis and modeling phase. This collaborative project is concerned with the lower trophic levels, and will be integrated with other synthesis and modeling studies that deal with grazers, predators, and other higher trophic levels.", "east": -64.6, "geometry": "POINT(-66.84 -66.405)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS", "is_usap_dc": true, "keywords": "R/V NBP; Not provided", "locations": null, "north": -64.8, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences; Antarctic Ocean and Atmospheric Sciences; Antarctic Organisms and Ecosystems; Antarctic Ocean and Atmospheric Sciences; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Fritsen, Christian; Vernet, Maria; Ross, Robin Macurda; Quetin, Langdon B.", "platforms": "Not provided; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "USAP-DC", "repositories": "R2R; USAP-DC", "science_programs": null, "south": -68.01, "title": "Collaborative Research: U.S. SO GLOBEC Synthesis and Modeling: Timing is Everything: The Dynamic Coupling among Phytoplankton, Ice, Ice Algae and Krill (PIIAK)", "uid": "p0000522", "west": -69.08}, {"awards": "8917076 Smith, Raymond", "bounds_geometry": "POLYGON((-49.8233 -60.2167,-48.99564 -60.2167,-48.16798 -60.2167,-47.34032 -60.2167,-46.51266 -60.2167,-45.685 -60.2167,-44.85734 -60.2167,-44.02968 -60.2167,-43.20202 -60.2167,-42.37436 -60.2167,-41.5467 -60.2167,-41.5467 -60.35003,-41.5467 -60.48336,-41.5467 -60.61669,-41.5467 -60.75002,-41.5467 -60.88335,-41.5467 -61.01668,-41.5467 -61.15001,-41.5467 -61.28334,-41.5467 -61.41667,-41.5467 -61.55,-42.37436 -61.55,-43.20202 -61.55,-44.02968 -61.55,-44.85734 -61.55,-45.685 -61.55,-46.51266 -61.55,-47.34032 -61.55,-48.16798 -61.55,-48.99564 -61.55,-49.8233 -61.55,-49.8233 -61.41667,-49.8233 -61.28334,-49.8233 -61.15001,-49.8233 -61.01668,-49.8233 -60.88335,-49.8233 -60.75002,-49.8233 -60.61669,-49.8233 -60.48336,-49.8233 -60.35003,-49.8233 -60.2167))", "dataset_titles": "Expedition Data", "datasets": [{"dataset_uid": "002326", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP9206"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "The Antarctic is now experiencing large springtime losses of stratospheric ozone, resulting in an increase in ultraviolet B (UVB, 280-320nm) radiation. The magnitude of ultraviolet radiation reaching the surface now approaches that measured in tropical latitudes. Perhaps more importantly, UVB radiation has increased in the Antarctic while both UVA (320-400nm) and photosynthetically available radiation (PAR, 400-700nm) have remained unchanged. Recent improvements in atmospheric modeling and technology in oceanographic instrumentation will be used in a six week field study during the austral spring 1990. The prime objective will be to document the impact of UV radiation on the phytoplankton community during the ice-edge spring bloom. During this time, oceanographic processes create favorable conditions for increased UVB susceptibility. Biological and bio-optical information will be used to define and quantify linkages between ozone-dependent oscillations in UV to PAR ratios and phytoplankton productivity. Special emphasis will be placed on defining biological restraints imposed by enhanced UVB and altered UVB:UVA:PAR ratios on the balance of UVB photodamage to photorepair, photoprotective and photosynthetic mechanisms operating in the Southern Ocean. The overall aim is to test the hypothesis that phytoplankton in Antarctic waters are adversely influenced by ozone depletion.", "east": -41.5467, "geometry": "POINT(-45.685 -60.88335)", "instruments": null, "is_usap_dc": false, "keywords": "R/V NBP", "locations": null, "north": -60.2167, "nsf_funding_programs": null, "paleo_time": null, "persons": "Smith, Raymond", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": -61.55, "title": "Ozone Diminution, Ultraviolet Radiation and Photoplankton Biology in Antarctic Waters", "uid": "p0000650", "west": -49.8233}, {"awards": "9615342 Neale, Patrick", "bounds_geometry": null, "dataset_titles": "Expedition data of LMG9809", "datasets": [{"dataset_uid": "002720", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG9809", "url": "https://www.rvdata.us/search/cruise/LMG9809"}, {"dataset_uid": "002719", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG9809", "url": "https://www.rvdata.us/search/cruise/LMG9809"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "Increases in ultraviolet-B radiation (UV-B, 280-320) associated with the Antarctic ozone hole have been shown to inhibit the photosynthesis of phytoplankton, but the overall effect on water column production is still a matter of debate and continued investigation. Investigations have also revealed that even at \"normal\" levels of Antarctic stratospheric ozone, UV-B and UV-A (320-400 nm) appear to have strong effects on water column production. The role of UV in the ecology of phytoplankton primary production has probably been underappreciated in the past and could be particularly important to the estimation of primary production in the presence of vertical mixing. This research focuses on quantifying UV effects on photosynthesis of Antarctic phytoplankton by defining biological weighting functions for UV-inhibition. In the past, techniques were developed to describe photosynthesis as a function of UV and visible irradiance using laboratory cultures. Further experimentation with natural assemblages from McMurdo Station in Antarctica showed that biological weighting functions are strongly related to light history. Most recently, measurements in the open waters of the Southern Ocean confirmed that there is substantial variability in the susceptibility of phytoplankton assemblages to UV. It was also discovered that inhibition of photosynthesis in Antarctic phytoplankton got progressively worse on the time scale of hours, with no evidence of recovery. Even under benign conditions, losses of photosynthetic capability persisted unchanged for several hours. This was in contrast with laboratory cultures and some natural assemblages which quickly attained a steady- state rate of photosynthesis during exposure to UV, reflecting a balance between damage and recovery processes. Slow reversal of UV-induced damage has profound consequences for water-column photosynthesis, especially during vertical mixing. Results to date have been used to model th e influence of UV, ozone depletion and vertical mixing on photosynthesis in Antarctic waters. Data indicate that normal levels of UV can have a significant impact on natural phytoplankton and that the effects can be exacerbated by ozone depletion as well as vertical mixing. Critical questions remain poorly resolved, however, and these are the focus of the present proposal. New theoretical and experimental approaches will be used to investigate UV responses in both the open waters of the Weddell-Scotia confluence and coastal waters near Palmer Station. In particular, measurements will be made of the kinetics of UV inhibition and recovery on time scales ranging from minutes to days. Variability in biological weighting functions between will be calculated for pelagic and coastal phytoplankton in the Southern Ocean. The results will provide absolute estimates of photosynthesis under in situ, as well as under altered, UV irradiance; broaden the range of assemblages for which biological weighting functions have been determined; and clarify how kinetics of inhibition and recovery should be represented in mixed layer models.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "R/V LMG", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Mopper, Kenneth; Neale, Patrick", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": null, "title": "New Approaches to Measuring and Understanding the Effects of Ultraviolet Radiation on Photosynthesis by Antarctic Phytoplankton", "uid": "p0000871", "west": null}, {"awards": "0125818 Gargett, Ann", "bounds_geometry": null, "dataset_titles": "Expedition Data; Expedition data of NBP0508", "datasets": [{"dataset_uid": "001584", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0508"}, {"dataset_uid": "002610", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0508", "url": "https://www.rvdata.us/search/cruise/NBP0508"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "Ultraviolet radiation influences the dynamics of plankton processes in the near-surface waters of most aquatic ecosystems. In particular, the Southern Ocean is affected in the austral spring period when biologically damaging ultraviolet radiation is enhanced by ozone depletion. While progress has been made in estimating the quantitative impact of ultraviolet radiation on bacteria and phytoplankton in the Southern Ocean, some important issues remain to be resolved. Little is known about responses in systems dominated by the colonial haptophyte Phaeocystis antarctica, which dominates spring blooms in a polyna that develops in the southern Ross Sea. The Ross Sea is also of interest because of the occurrence of open water at a far southerly location in the spring, well within the ozone hole, and continuous daylight, with implications for the regulation of DNA repair. A number of studies suggest that vertical mixing can significant modify the impact of ultraviolet radiation in the Southern Ocean and elsewhere. However, there are limited measurements of turbulence intensity in the surface layer and measurements have not been integrated with parallel studies of ultraviolet radiation effects on phytoplankton and bacterioplankton. To address these issues, this collaborative study will focus on vertical mixing and the impact of ultraviolet radiation in the Ross Sea. The spectral and temporal responses of phytoplankton and bacterioplankton to ultraviolet radiation will be characterized in both laboratory and solar incubations. These will lead to the definition of biological weighting functions and response models capable of predicting the depth and time distribution of ultraviolet radiation impacts on photosynthesis, bacterial incorporation and DNA damage in the surface layer. Diel sampling will measure depth-dependent profiles of DNA damage, bacterial incorporation, photosynthesis and fluorescence parameters over a 24 h cycle. Sampling will include stations with contrasting wind-driven mixing and stratification as the polyna develops. The program of vertical mixing measurements is optimized for the typical springtime Ross Sea situation in which turbulence of intermediate intensity is insufficient to mix the upper layer thoroughly in the presence of stabilizing influences like solar heating and/or surface freshwater input from melting ice. Fine-scale vertical density profiles will be measured with a free-fall CTD unit and the profiles will be used to directly estimate large-eddy scales by determining Thorpe scales. Eddy scales and estimated turbulent diffusivities will be directly related to surface layer effects, and used to generate lagrangian depth-time trajectories in models of ultraviolet radiation responses in the surface mixed layer. The proposed research will be the first in-depth study of ultraviolet radiation effects in the Ross Sea and provide a valuable comparison with previous work in the Weddell-Scotia Confluence and Palmer Station regions. It will also enhance the understanding of vertical mixing processes, trophic interactions and biogeochemical cycling in the Ross Sea.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e PRESSURE/HEIGHT METERS \u003e PRESSURE SENSORS; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e TURBIDITY METERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ADCP", "is_usap_dc": false, "keywords": "R/V NBP; B-15J", "locations": "B-15J", "north": null, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Neale, Patrick", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": null, "title": "Collaborative Research: Interactive effects of UV and vertical mixing on phytoplankton and bacterioplankton in the Ross Sea", "uid": "p0000822", "west": null}, {"awards": "9317587 Smith, Walker", "bounds_geometry": null, "dataset_titles": "Expedition Data; Expedition data of NBP9406", "datasets": [{"dataset_uid": "002582", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP9406", "url": "https://www.rvdata.us/search/cruise/NBP9406"}, {"dataset_uid": "002252", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP9406"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "The growing season for phytoplankton in polar oceans is short, but intense. There is an increasing body of evidence that in many Antarctic habitats, the most active period may be very early in the season, a period that has not been emphasized in previous investigations. This project is part of an interdisciplinary program that focuses on the dynamics of the spring phytoplankton bloom in a highly productive subsystem of the Antarctic, the Ross Sea. The overall program will test hypotheses related to the initiation of the phytoplankton bloom shortly after the onset of ice melt, the mechanisms controlling phytoplankton growth and productivity in spring, the implications and short-term fate of high productivity in spring, and the transition from spring to midsummer conditions. This component will conduct a set of process-oriented experiments designed to elucidate the controls of phytoplankton productivity, growth and accumulation as well as the mechanisms which control bacterial abundance and productivity in Antarctic waters. Specifically, the relative photosynthetic and nutrient (nitrate, ammonium) characteristics of diatom- vs. Phaeocystis- dominated assemblages will be examined to test if Phaeocystis simply grows faster under spring conditions in the Ross Sea. Phytoplankton and bacterial biomass, productivity and their interactions will be measured to elucidate the complex physical-chemical-biological interactions which occur. Substantial understanding of the mechanisms controlling phytoplankton growth and productivity in spring, the implications and short-term fate of high productivity in spring, and the transition from spring to midsummer conditions will result from this research. Finally, because the Antarctic is the ocean\u0027s largest high-nutrient, low biomass system, and hence has the greatest potential for sequestering carbon dioxide, knowledge of the dynamics of the Ross Sea phytoplankton will also increase our understanding of the carbo n cycle of the Southern Ocean.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "R/V NBP", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Smith, Walker", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": null, "title": "Collaborative Research: Bloom Dynamics and Food Web Structure in the Ross Sea: Primary Productivity, New Production and Bacterial Growth", "uid": "p0000802", "west": null}, {"awards": "0632399 Jefferies, Stuart", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Tomographic Imaging of the Velocity and Magnetic Fields in the Sun\u0027s Atmosphere", "datasets": [{"dataset_uid": "600152", "doi": "10.15784/600152", "keywords": "Antarctica; Cosmos; Satellite Remote Sensing; Sun", "people": "Jefferies, Stuart M.", "repository": "USAP-DC", "science_program": null, "title": "Tomographic Imaging of the Velocity and Magnetic Fields in the Sun\u0027s Atmosphere", "url": "https://www.usap-dc.org/view/dataset/600152"}], "date_created": "Wed, 10 Mar 2010 00:00:00 GMT", "description": "The proposal is to develop an instrument that can simultaneously measure the sound speed and magnetic fields at three heights in the solar atmosphere. The instrument will use magneto-optical filters tuned to the solar absorption lines at 422 nm (Ca I), 589 nm (Na D2), and 770 nm (K) to make measurements of Doppler velocities and longitudinal magnetic field. These lines form in the mid- and low-chromosphere and photosphere, respectively. In addition, the instrument will also use a Fabry-Perot etalon as a narrowband filter to measure the intensity variations of the 1083 nm (He I) line that is formed high in the chromosphere and which shows the location of the \"foot points\" of coronal holes. Together, the four lines will allow studying wave motions throughout the solar atmosphere. The instrument will record images of the Sun every 10 seconds with a spatial resolution of 1 arc-second. Thus, the project will be fostering the development of existing magneto-optical filter technology to a new level. Upon construction, the telescope will be tested at South Pole for a long period of uninterrupted observations. Both the local and global helioseismic analysis procedures will be utilized to identify and to characterize different types of waves present in the solar atmosphere. These observations will allow determining the structure and dynamics of the Sun\u0027s atmosphere through seismic measurements and, thus, improve the atmosphere models, assess the role of waves in heating the chromosphere/corona and driving the solar wind, and better understand how the Sun\u0027s atmosphere couples to the interior. The broader impact of the proposed project is two fold. First, there is a potential benefit to the science and to the society because it is believed that the solar atmosphere is a \"home\" to many phenomena that can have a direct effect on the solar activity, including flares, coronal mass ejections, and the solar wind. Understanding the structure and dynamics of the solar atmosphere will therefore lead to a better understanding of the Sun-Earth connection. The collected data will be made available to other researchers at DVDs. The broader audience of general public will be reached through presentations at high schools, libraries, and community events, and news articles in the general press. Most of the research materials will also be placed in the Web.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -60.0, "nsf_funding_programs": "Antarctic Astrophysics and Geospace Sciences", "paleo_time": null, "persons": "Jefferies, Stuart M.", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Tomographic Imaging of the Velocity and Magnetic Fields in the Sun\u0027s Atmosphere", "uid": "p0000526", "west": -180.0}, {"awards": "9220373 Neale, Patrick", "bounds_geometry": null, "dataset_titles": "Expedition Data; Expedition data of NBP9306", "datasets": [{"dataset_uid": "002282", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP9306"}, {"dataset_uid": "002589", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP9306", "url": "https://www.rvdata.us/search/cruise/NBP9306"}], "date_created": "Fri, 19 Jun 2009 00:00:00 GMT", "description": "Increases in middle ultraviolet radiation associated with the Antarctic ozone hole have been shown to inhibit the photosynthesis of phytoplankton, and results have been extrapolated to estimate the effect of ozone depletion on primary productivity in the marginal ice zone. This research will refine the assessment by specifying detailed wavelength-dependent biological weighting functions for the inhibition of photosynthesis by ultraviolet radiation, and by considering the mitigating effects of vertical mixing. Biological weighting functions of phytoplankton in the marginal ice zone will be measured under controlled conditions and applied in a new model of photosynthesis to predict primary productivity in situ, as well as under altered ultraviolet irradiance. These predictions will be compared with observations on samples from the water column and with measurements during incubations of several hours under different irradiance regimes. Results of these comparisons will be used to test the model and to quantify the potential artifact of long incubations. Assumptions about the kinetics of photoinhibition and recovery, critical to modeling the effects of vertical mixing, will be examined with time-course experiments. Results will be incorporated into a model of photosynthesis and photoinhibition in the water column that will be used to predict the influence of ozone depletion on marine primary production, particularly in the marginal zone.", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS", "is_usap_dc": false, "keywords": "R/V NBP", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Neale, Patrick", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": null, "title": "Effects of Ultraviolet Radiation on the Photosynthesis of Phytoplankton in the Antarctic Marginal Ice Zone", "uid": "p0000808", "west": null}, {"awards": "0440478 Tang, Kam", "bounds_geometry": "POINT(166.66267 -77.85067)", "dataset_titles": "Environmental and Ecological Regulation of Differences and Interactions between Solitary and Colonial Forms of Phaeocystis Antarctica", "datasets": [{"dataset_uid": "600043", "doi": "10.15784/600043", "keywords": "Biota; Mcmurdo Sound; Oceans; Phytoplankton; Ross Sea; Southern Ocean; Zooplankton", "people": "Smith, Walker; Tang, Kam", "repository": "USAP-DC", "science_program": null, "title": "Environmental and Ecological Regulation of Differences and Interactions between Solitary and Colonial Forms of Phaeocystis Antarctica", "url": "https://www.usap-dc.org/view/dataset/600043"}], "date_created": "Mon, 04 May 2009 00:00:00 GMT", "description": "Phaeocystis Antarctica is a widely distributed phytoplankton that forms dense blooms and aggregates in the Southern Ocean. This phytoplankton and plays important roles in polar ecology and biogeochemistry, in part because it is a dominant primary producer, a main component of organic matter vertical fluxes, and the principal producer of volatile organic sulfur in the region. Yet P. Antarctica is also one of the lesser known species in terms of its physiology, life history and trophic relationships with other organisms; furthermore, information collected on other Phaeocystis species and from different locations may not be applicable to P. Antarctica in the Ross Sea. P. Antarctica occurs mainly as two morphotypes: solitary cells and mucilaginous colonies, which differ significantly in size, architecture and chemical composition. Relative dominance between solitary cells and colonies determines not only the size spectrum of the population, but also its carbon dynamics, nutrient uptake and utilization. Conventional thinking of the planktonic trophic processes is also challenged by the fact that colony formation could effectively alter the predator-prey interactions and interspecific competition. However, the factors that regulate the differences between solitary and colonial forms of P. Antarctica are not well-understood. The research objective of this proposal is therefore to address these over-arching questions:\u003cbr/\u003eo Do P. Antarctica solitary cells and colonies differ in growth, composition and\u003cbr/\u003ephotosynthetic rates?\u003cbr/\u003eo How do nutrients and grazers affect colony development and size distribution of P. \u003cbr/\u003eAntarctica?\u003cbr/\u003eo How do nutrients and grazers act synergistically to affect the long-term population\u003cbr/\u003edynamics of P. Antarctica? Experiments will be conducted in the McMurdo station with natural P. Antarctica assemblages and co-occurring grazers. Laboratory experiments will be conducted to study size-specific growth and photosynthetic rates of P. Antarctica, size-specific grazing mortality due to microzooplankton and mesozooplankton, the effects of macronutrients on the (nitrogen compounds) relative dominance of solitary cells and colonies, and the effects of micronutrient (Fe) and grazing related chemical signals on P. Antarctica colony development. Because this species is of critical importance in the Southern Ocean, and because this research will provide critical information on factors that regulate the role of P.Antarctica in food webs and biogeochemical cycles, a major gap in knowledge will be addressed. This project will train two marine science PhD students. The investigators will also collaborate with the School of Education and a marine science museum to communicate polar science to a broader audience.", "east": 166.66267, "geometry": "POINT(166.66267 -77.85067)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -77.85067, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Tang, Kam; Smith, Walker", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.85067, "title": "Environmental and Ecological Regulation of Differences and Interactions between Solitary and Colonial forms of Phaeocystis antarctica", "uid": "p0000214", "west": 166.66267}, {"awards": "0443403 Measures, Christopher; 0230445 Measures, Christopher; 0444040 Zhou, Meng", "bounds_geometry": "POLYGON((-63 -60.3,-62 -60.3,-61 -60.3,-60 -60.3,-59 -60.3,-58 -60.3,-57 -60.3,-56 -60.3,-55 -60.3,-54 -60.3,-53 -60.3,-53 -60.77,-53 -61.24,-53 -61.71,-53 -62.18,-53 -62.65,-53 -63.12,-53 -63.59,-53 -64.06,-53 -64.53,-53 -65,-54 -65,-55 -65,-56 -65,-57 -65,-58 -65,-59 -65,-60 -65,-61 -65,-62 -65,-63 -65,-63 -64.53,-63 -64.06,-63 -63.59,-63 -63.12,-63 -62.65,-63 -62.18,-63 -61.71,-63 -61.24,-63 -60.77,-63 -60.3))", "dataset_titles": "Expedition Data", "datasets": [{"dataset_uid": "001663", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG0402"}], "date_created": "Mon, 12 Jan 2009 00:00:00 GMT", "description": "The Shackleton Fracture Zone (SFZ) in the Drake Passage defines a boundary between low and high phytoplankton waters. West of Drake Passage, Southern Ocean waters south of the Polar Front and north of the Antarctic continent shelf have very low satellite-derived surface chlorophyll concentrations. Chlorophyll and mesoscale eddy kinetic energy are higher east of SFZ compared to values west of the ridge. In situ data from a 10-year survey of the region as part of the National Marine Fisheries Service\u0027s Antarctic Marine Living Resources program confirm the existence of a strong hydrographic and chlorophyll gradient in the region. An interdisciplinary team of scientists hypothesizes that bathymetry, including the 2000 m deep SFZ, influences mesoscale circulation and transport of iron leading to the observed phytoplankton patterns. To address this\u003cbr/\u003ehypothesis, the team proposes to examine phytoplankton and bacterial physiological states (including responses to iron enrichment) and structure of the plankton communities from virus to zooplankton, the concentration and distribution of Fe, Mn, and Al, and mesoscale flow patterns near the SFZ. Relationships between iron concentrations and phytoplankton characteristics will be examined in the context of the mesoscale transport of trace nutrients to determine how much of the observed variability in phytoplankton biomass can be attributed to iron supply, and to determine the most important sources of iron to pelagic waters east of the Drake Passage. The goal is to better understand how plankton productivity and community structure in the Southern Ocean are affected by the coupling between bathymetry, mesoscale circulation, and limiting nutrient distributions.\u003cbr/\u003e\u003cbr/\u003eThe research program includes rapid surface surveys of chemical, plankton, and hydrographic properties complemented by a mesoscale station grid for vertical profiles, water sampling, and bottle incubation enrichment experiments. Distributions of manganese and aluminum will be determined to help distinguish aeolian, continental shelf and upwelling sources of iron. The physiological state of the phytoplankton will be monitored by active fluorescence methods sensitive to the effects of iron limitation. Mass concentrations of pigment, carbon and nitrogen will be obtained by analysis of filtered samples, cell size distributions by flow cytometry, and species identification by microscopy. Primary production and photosynthesis parameters (absorption, quantum yields, variable fluorescence) will be measured on depth profiles, during surface surveys and on bulk samples from enrichment experiments. Viruses and bacteria will be examined for abundances, and bacterial production will be assessed in terms of whether it is limited by either iron or organic carbon sources. The proposed work will improve our understanding of processes controlling distributions of iron and the response of plankton communities in the Southern Ocean. This proposal also includes an outreach component comprised of Research Experiences for Undergraduates (REU), Teachers Experiencing the Antarctic and Arctic (TEA), and the creation of an educational website and K-12 curricular modules based on the project.", "east": -53.0, "geometry": "POINT(-58 -62.65)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e PRESSURE/HEIGHT METERS \u003e PRESSURE SENSORS; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e TURBIDITY METERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ADCP", "is_usap_dc": true, "keywords": "R/V LMG", "locations": null, "north": -60.3, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Measures, Christopher; Selph, Karen; Zhou, Meng", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": -65.0, "title": "Collaborative Research: Plankton Community Structure and Iron Distribution in the Southern Drake Passage", "uid": "p0000585", "west": -63.0}, {"awards": "0127022 Jeffrey, Wade", "bounds_geometry": "POLYGON((-177.639 -43.5676,-143.1091 -43.5676,-108.5792 -43.5676,-74.0493 -43.5676,-39.5194 -43.5676,-4.9895 -43.5676,29.5404 -43.5676,64.0703 -43.5676,98.6002 -43.5676,133.1301 -43.5676,167.66 -43.5676,167.66 -46.99877,167.66 -50.42994,167.66 -53.86111,167.66 -57.29228,167.66 -60.72345,167.66 -64.15462,167.66 -67.58579,167.66 -71.01696,167.66 -74.44813,167.66 -77.8793,133.1301 -77.8793,98.6002 -77.8793,64.0703 -77.8793,29.5404 -77.8793,-4.9895 -77.8793,-39.5194 -77.8793,-74.0493 -77.8793,-108.5792 -77.8793,-143.1091 -77.8793,-177.639 -77.8793,-177.639 -74.44813,-177.639 -71.01696,-177.639 -67.58579,-177.639 -64.15462,-177.639 -60.72345,-177.639 -57.29228,-177.639 -53.86111,-177.639 -50.42994,-177.639 -46.99877,-177.639 -43.5676))", "dataset_titles": "Expedition Data; Ross Sea microbial biomass and production", "datasets": [{"dataset_uid": "600029", "doi": "10.15784/600029", "keywords": "Biota; Chemistry:fluid; Chemistry:Fluid; CTD Data; Microbiology; Oceans; Phytoplankton; Ross Sea; Southern Ocean", "people": "Jeffrey, Wade H.", "repository": "USAP-DC", "science_program": null, "title": "Ross Sea microbial biomass and production", "url": "https://www.usap-dc.org/view/dataset/600029"}, {"dataset_uid": "001690", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0304B"}, {"dataset_uid": "001584", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0508"}], "date_created": "Thu, 12 Jun 2008 00:00:00 GMT", "description": "Ultraviolet radiation influences the dynamics of plankton processes in the near-surface waters of most aquatic ecosystems. In particular, the Southern Ocean is affected in the austral spring period when biologically damaging ultraviolet radiation is enhanced by ozone depletion. While progress has been made in estimating the quantitative impact of ultraviolet radiation on bacteria and phytoplankton in the Southern Ocean, some important issues remain to be resolved. Little is known about responses in systems dominated by the colonial haptophyte Phaeocystis antarctica, which dominates spring blooms in a polyna that develops in the southern Ross Sea. The Ross Sea is also of interest because of the occurrence of open water at a far southerly location in the spring, well within the ozone hole, and continuous daylight, with implications for the regulation of DNA repair. A number of studies suggest that vertical mixing can significant modify the impact of ultraviolet radiation in the Southern Ocean and elsewhere. However, there are limited measurements of turbulence intensity in the surface layer and measurements have not been integrated with parallel studies of ultraviolet radiation effects on phytoplankton and bacterioplankton. To address these issues, this collaborative study will focus on vertical mixing and the impact of ultraviolet radiation in the Ross Sea. The spectral and temporal responses of phytoplankton and bacterioplankton to ultraviolet radiation will be characterized in both laboratory and solar incubations. These will lead to the definition of biological weighting functions and response models capable of predicting the depth and time distribution of ultraviolet radiation impacts on photosynthesis, bacterial incorporation and DNA damage in the surface layer. Diel sampling will measure depth-dependent profiles of DNA damage, bacterial incorporation, photosynthesis and fluorescence parameters over a 24 h cycle. Sampling will include stations with contrasting wind-driven mixing and stratification as the polyna develops. The program of vertical mixing measurements is optimized for the typical springtime Ross Sea situation in which turbulence of intermediate intensity is insufficient to mix the upper layer thoroughly in the presence of stabilizing influences like solar heating and/or surface freshwater input from melting ice. Fine-scale vertical density profiles will be measured with a free-fall CTD unit and the profiles will be used to directly estimate large-eddy scales by determining Thorpe scales. Eddy scales and estimated turbulent diffusivities will be directly related to surface layer effects, and used to generate lagrangian depth-time trajectories in models of ultraviolet radiation responses in the surface mixed layer. The proposed research will be the first in-depth study of ultraviolet radiation effects in the Ross Sea and provide a valuable comparison with previous work in the Weddell-Scotia Confluence and Palmer Station regions. It will also enhance the understanding of vertical mixing processes, trophic interactions and biogeochemical cycling in the Ross Sea.", "east": 167.66, "geometry": "POINT(-4.9895 -60.72345)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e PRESSURE/HEIGHT METERS \u003e PRESSURE SENSORS; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e TURBIDITY METERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ADCP; IN SITU/LABORATORY INSTRUMENTS \u003e SAMPLERS \u003e BOTTLES/FLASKS/JARS \u003e WATER BOTTLES; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e FLUORESCENCE MICROSCOPY; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e MICROSCOPES; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e FLUOROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e SAMPLERS \u003e BOTTLES/FLASKS/JARS \u003e GO-FLO BOTTLES", "is_usap_dc": true, "keywords": "R/V NBP; B-15J", "locations": "B-15J", "north": -43.5676, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Jeffrey, Wade H.; Neale, Patrick", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "USAP-DC", "repositories": "R2R; USAP-DC", "science_programs": null, "south": -77.8793, "title": "Collaborative Proposal: Interactive Effects of UV Radiation and Vertical Mixing on Phytoplankton and Bacterial Productivity of Ross See Phaeocystis Blooms", "uid": "p0000578", "west": -177.639}]

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