USAP-DC

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

[{"awards": "1542723 Alexander, Becky", "bounds_geometry": "POINT(-112.05 -79.28)", "dataset_titles": "WAIS Divide ice core nitrate isotopes", "datasets": [{"dataset_uid": "601456", "doi": "10.15784/601456", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Chemistry; Ice Core Records; Nitrate; Nitrate Isotopes; WAIS Divide Ice Core; West Antarctic Ice Sheet", "people": "Alexander, Becky", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide ice core nitrate isotopes", "url": "https://www.usap-dc.org/view/dataset/601456"}], "date_created": "Mon, 13 Feb 2023 00:00:00 GMT", "description": "The Earth\u0027s atmosphere is a highly oxidizing medium. The abundance of oxidants such as ozone in the atmosphere strongly influences the concentrations of pollutants and greenhouse gases, with implications for human health and welfare. Because oxidants are not preserved in geological archives, knowledge of how oxidants have varied in the past under changing climate conditions is extremely limited. This award will measure a proxy for oxidant concentrations in a West Antarctic ice core over several major climate transitions over the past 50,000 years. These measurements will complement similar measurements from a Greenland ice core, which showed significant changes in atmospheric oxidants over major climate transitions covering this same time period. The addition of measurements from Antarctica will allow researchers to examine if the oxidant changes suggested by the Greenland ice core record are regional or global in scale. Knowledge of how oxidants vary naturally with climate will better inform predictions of the composition of the future atmosphere under a warming climate. This award will support measurements of the isotopic composition of nitrate in a West Antarctic ice core as a proxy for oxidant concentrations in the past atmosphere. The nitrogen isotopes of nitrate provide information on the degree of preservation of nitrate in the ice core record, and thus aid in the interpretation of the observed variability in the observed nitrate concentrations and oxygen isotopes in ice core records. By providing information about the spatial scale of oxidant changes over abrupt climate change events during the last glacial period, this project may also improve our understanding of mechanisms driving these abrupt events. Insight from this project will prove valuable for forecasting the response of stratospheric circulation to climate change, which has large implications for climate feedbacks and tropospheric composition. In addition, the information gleaned from this project on the mechanisms and feedbacks during abrupt climate change events will help determine the likelihood of such rapid events occurring in the future, which would have dramatic impacts on humankind. This award will provide training for one graduate and one undergraduate student, and will support the development of a hands-on activity related to rapid climate change to be used at the annual Polar Science Weekend at the Pacific Science Center in Seattle, WA.", "east": -112.05, "geometry": "POINT(-112.05 -79.28)", "instruments": null, "is_usap_dc": true, "keywords": "Nitrate Isotopes; ICE CORE RECORDS; WAIS Divide; LABORATORY", "locations": "WAIS Divide", "north": -79.28, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Alexander, Becky", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -79.28, "title": "Measuring an Ice-core Proxy for Relative Oxidant Abundances over Glacial-interglacial and Rapid Climate changes in a West Antarctic Ice Core", "uid": "p0010403", "west": -112.05}, {"awards": "2147045 Learman, Deric", "bounds_geometry": "POLYGON((-180 -60,-168 -60,-156 -60,-144 -60,-132 -60,-120 -60,-108 -60,-96 -60,-84 -60,-72 -60,-60 -60,-60 -62,-60 -64,-60 -66,-60 -68,-60 -70,-60 -72,-60 -74,-60 -76,-60 -78,-60 -80,-72 -80,-84 -80,-96 -80,-108 -80,-120 -80,-132 -80,-144 -80,-156 -80,-168 -80,180 -80,171 -80,162 -80,153 -80,144 -80,135 -80,126 -80,117 -80,108 -80,99 -80,90 -80,90 -78,90 -76,90 -74,90 -72,90 -70,90 -68,90 -66,90 -64,90 -62,90 -60,99 -60,108 -60,117 -60,126 -60,135 -60,144 -60,153 -60,162 -60,171 -60,-180 -60))", "dataset_titles": "Physical and geochemical data from shelf sediments eastern Antarctica", "datasets": [{"dataset_uid": "601876", "doi": "10.15784/601876", "keywords": "Antarctica; Cryosphere", "people": "Learman, Deric", "repository": "USAP-DC", "science_program": null, "title": "Physical and geochemical data from shelf sediments eastern Antarctica", "url": "https://www.usap-dc.org/view/dataset/601876"}], "date_created": "Tue, 30 Aug 2022 00:00:00 GMT", "description": "Microbes in Antarctic surface marine sediments have an important role in degrading organic matter and releasing nutrients to the ocean. Organic matter degradation is at the center of the carbon cycle in the ocean, providing valuable information on nutrient recycling, food availability to animals and carbon dioxide release to the atmosphere. The functionality of these microbes has been inferred by their genomics, however these methods only address the possible function, not their actual rates. In this project the PIs plan to combine genomics methods with cellular estimates of enzyme abundance and activity as a way to determine the rates of carbon degradation. This project aims to sample in several regions of Antarctica to provide a large-scale picture of the processes under study and understand the importance of microbial community composition and environmental factors, such as primary productivity, have on microbial activity. The proposed work will combine research tools such as metagenomics, meta-transcriptomics, and metabolomics coupled with chemical data and enzyme assays to establish degradation of organic matter in Antarctic sediments. This project benefits NSFs goals of understanding the adaptation of Antarctic organisms to the cold and isolated environment, critical to predict effects of climate change to polar organisms, as well as contribute to our knowledge of how Antarctic organisms have adapted to this environment. Society will benefit from this project by education of 2 graduate students, undergraduates and K-12 students as well as increase public literacy through short videos production shared in YouTube. The PIs propose to advance understanding of polar microbial community function, by measuring enzyme and gene function of complex organic matter degradation in several ocean regions, providing a circum-Antarctic description of sediment processes. Two hypotheses are proposed. The first hypothesis states that many genes for the degradation of complex organic matter will be shared in sediments throughout a sampling transect and that where variations in gene content occur, it will reflect differences in the quantity and quality of organic matter, not regional variability. The second hypothesis states that a fraction of gene transcripts for organic matter degradation will not result in measurable enzyme activity due to post-translational modification or rapid degradation of the enzymes. The PIs will analyze sediment cores already collected in a 2020 cruise to the western Antarctic Peninsula with the additional request of participating in a cruise in 2023 to East Antarctica. The PIs will analyze sediments for metagenomics, meta-transcriptomics, and metabolomics coupled with geochemical data and enzyme assays to establish microbial degradation of complex organic matter in Antarctic sediments. Organic carbon concentrations and content in sediments will be measured with \u03b413C, \u03b415N, TOC porewater fluorescence in bulk organic carbon. Combined with determination of geographical variability as well as dependence on carbon sources, results from this study could provide the basis for new hypotheses on how climate variability, with increased water temperature, affects geochemistry in the Southern Ocean. 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": 90.0, "geometry": "POINT(-165 -70)", "instruments": null, "is_usap_dc": true, "keywords": "BENTHIC; ECOSYSTEM FUNCTIONS; Weddell Sea; Antarctic Peninsula; SEDIMENT CHEMISTRY; R/V NBP", "locations": "Antarctic Peninsula; Weddell Sea", "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Learman, Deric", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -80.0, "title": "Collaborative Research: ANT LIA: Connecting Metagenome Potential to Microbial Function: Investigating Microbial Degradation of Complex Organic Matter Antarctic Benthic Sediments", "uid": "p0010373", "west": -60.0}, {"awards": "1745064 Perez-Huerta, Alberto; 1745057 Walker, Sally; 1745080 Gillikin, David", "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": "Analysis of striae groups and interstrial increments from Adamussium colbecki valves from Explorers Cove and Bay of Sails; Annual growth of Adamussium colbecki from Explorers Cove and Bay of Sails; Linking Modern Benthic Communities and Taphonomic Processes to the Stratigraphic Record of Antarctic Cores; Nitrogen, carbon, and oxygen isotopes in the shell of the Antarctic scallop Adamussium colbecki as a proxy for sea ice cover in Antarctica.; Stable isotopes of Oxygen and Carbon in Adamissium colbecki from Explorers Cove and Bay of Sails", "datasets": [{"dataset_uid": "601764", "doi": "10.15784/601764", "keywords": "Adamussium Colbecki; Antarctica; Biota; Carbon Isotopes; Explorers Cove; Nitrogen Isotopes; Oxygen Isotope; Scallop", "people": "Gillikin, David; Puhalski, Emma; Camarra, Steve; Cronin, Kelly; Verheyden, Anouk; Walker, Sally", "repository": "USAP-DC", "science_program": null, "title": "Nitrogen, carbon, and oxygen isotopes in the shell of the Antarctic scallop Adamussium colbecki as a proxy for sea ice cover in Antarctica.", "url": "https://www.usap-dc.org/view/dataset/601764"}, {"dataset_uid": "601468", "doi": "10.15784/601468", "keywords": "Adamussium Colbecki; Antarctica; Growth; McMurdo Sound; Shell Fish", "people": "Walker, Sally; Cronin, Kelly", "repository": "USAP-DC", "science_program": null, "title": "Annual growth of Adamussium colbecki from Explorers Cove and Bay of Sails", "url": "https://www.usap-dc.org/view/dataset/601468"}, {"dataset_uid": "601469", "doi": "10.15784/601469", "keywords": "Adamussium Colbecki; Antarctica; McMurdo", "people": "Walker, Sally; Cronin, Kelly", "repository": "USAP-DC", "science_program": null, "title": "Analysis of striae groups and interstrial increments from Adamussium colbecki valves from Explorers Cove and Bay of Sails", "url": "https://www.usap-dc.org/view/dataset/601469"}, {"dataset_uid": "601761", "doi": "10.15784/601761", "keywords": "Adamussium Colbecki; Antarctica; Bay Of Sails; Carbon; Explorers Cove; McMurdo Sound; Oxygen; Stable Isotopes", "people": "Walker, Sally; Cronin, Kelly; Puhalski, Emma; Perez-Huerta, Alberto; Bowser, Samuel S.; Verheyden, Anouk; Gillikin, David; Camarra, Steve; Andrus, Fred", "repository": "USAP-DC", "science_program": null, "title": "Stable isotopes of Oxygen and Carbon in Adamissium colbecki from Explorers Cove and Bay of Sails", "url": "https://www.usap-dc.org/view/dataset/601761"}, {"dataset_uid": "600077", "doi": "10.15784/600077", "keywords": "Antarctica; Biota; Glaciers/ice Sheet; Glaciers/Ice Sheet; McMurdo Sound; Oceans; Sample/collection Description; Sample/Collection Description", "people": "Walker, Sally", "repository": "USAP-DC", "science_program": null, "title": "Linking Modern Benthic Communities and Taphonomic Processes to the Stratigraphic Record of Antarctic Cores", "url": "https://www.usap-dc.org/view/dataset/600077"}], "date_created": "Fri, 06 Aug 2021 00:00:00 GMT", "description": "The goal of this project is to discover whether the Antarctic scallop, Adamussium colbecki, provides a guide to sea-ice conditions in nearshore Antarctica today and in the past. Scallops may grow slower and live longer in habitats where sea ice persists for many years, limited by food, compared to habitats where sea ice melts out annually. Also, the chemicals retained in the shell during growth may provide crucial habitat information related to not only changing sea-ice conditions but also the type of food, whether it is recycled from the seafloor or produced by algae blooming when sea ice has melted. Unlocking the ecological imprint captured within the shell of the Antarctic Scallop will increase our understanding of changing sea-ice conditions in Antarctica. Further, because the Antarctic scallop had relatives living at the time when the Antarctic ice sheet first appeared, the scallop shell record may contain information on the stability of the ice sheet and the history of Antarctic shallow seas. Funding will also be integral for training a new generation of geoscientists in fossil and chemical forensics related to shallow sea habitats in Antarctica. Scallops are worldwide in distribution, are integral for structuring marine communities have an extensive fossil record dating to the late Devonian, and are increasingly recognized as important paleoenvironmental proxies because they are generally well preserved in the sediment and rock record. The primary goal of this project is to assess the differences in growth, lifespan, and chemistry (stable isotopes, trace elements) archived in the shell of the Antarctic scallop that may be indicative of two ice states: persistent (multiannual) sea ice at Explorers Cove (EC) and annual sea ice (that melts out every year) at Bay of Sails (BOS), western McMurdo Sound, Antarctica. This project will investigate growth and lifespan proxies (physical and geochemical) and will use high-resolution records of stable oxygen isotopes to determine if a melt-water signal is archived in A. colbecki shells and whether that signal captures the differing ice behavior at two sites (EC versus BOS). Stable isotopes of carbon and nitrogen in association with trace elements will be used to examine subannual productivity spikes indicative of phytoplankton blooms, which are predicted to be more pronounced during open ocean conditions. Small growth increments in the outer calcite layer will be assessed to determine if they represent fortnightly growth, if so, they could provide a high-resolution proxy for monthly environmental processes. Unlocking the environmental archive preserved in A. colbecki shells may prove to be an important proxy for understanding changing sea-ice conditions in Antarctica\u0027s past. Funding will support a Ph.D. student and undergraduates from multiple institutions working on independent research projects. Web content focused on Antarctic marine communities will be designed for museum outreach, reaching thousands of middle-school children each year. 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": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Amd/Us; PALEOCLIMATE RECONSTRUCTIONS; AMD; Dry Valleys; USAP-DC; LABORATORY; USA/NSF", "locations": "Dry Valleys", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Walker, Sally; Gillikin, David; Perez-Huerta, Alberto; Andrus, Fred", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative research: The Antarctic Scallop as Key to Paleoenvironments and Sea Ice Conditions: Understanding the Modern to Predict the Past", "uid": "p0010238", "west": -180.0}, {"awards": "1744871 Robinson, Rebecca", "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": "Diatom assemblage from IODP Site U1357; Diatom-bound and bulk sedimentary N isotopes from ODP Site 1098, Western Antarctic Peninsula; Diatom-bound and bulk sedimentary nitrogen isotopes from IODP Site U1357; Dissolved nutrients, cell counts, and nitrogen isotope measurements from Chaetoceros socialis culture experiments; ODP Site 1098 deglacial diatom assemblage; Sediment chemistry of ODP Site 1098", "datasets": [{"dataset_uid": "601816", "doi": "10.15784/601816", "keywords": "Antarctica; Antarctic Peninsula; Cryosphere; Geochemistry; Sediment", "people": "Robinson, Rebecca; Kelly, Roger; Jones, Colin; Dove, Isabel", "repository": "USAP-DC", "science_program": null, "title": "Diatom-bound and bulk sedimentary N isotopes from ODP Site 1098, Western Antarctic Peninsula", "url": "https://www.usap-dc.org/view/dataset/601816"}, {"dataset_uid": "601818", "doi": "10.15784/601818", "keywords": "Antarctica; Cryosphere; Geochemistry; Sediment; Wilkes Land", "people": "Dove, Isabel", "repository": "USAP-DC", "science_program": null, "title": "Diatom assemblage from IODP Site U1357", "url": "https://www.usap-dc.org/view/dataset/601818"}, {"dataset_uid": "601727", "doi": "10.15784/601727", "keywords": "Antarctica", "people": "Dove, Isabel", "repository": "USAP-DC", "science_program": null, "title": "Dissolved nutrients, cell counts, and nitrogen isotope measurements from Chaetoceros socialis culture experiments", "url": "https://www.usap-dc.org/view/dataset/601727"}, {"dataset_uid": "601777", "doi": "10.15784/601777", "keywords": "Antarctica; Antarctic Peninsula; Cryosphere; Sediment Core Data", "people": "Dove, Isabel", "repository": "USAP-DC", "science_program": null, "title": "ODP Site 1098 deglacial diatom assemblage", "url": "https://www.usap-dc.org/view/dataset/601777"}, {"dataset_uid": "601778", "doi": "10.15784/601778", "keywords": "Antarctica; Antarctic Peninsula; Cryosphere", "people": "Dove, Isabel", "repository": "USAP-DC", "science_program": null, "title": "Sediment chemistry of ODP Site 1098", "url": "https://www.usap-dc.org/view/dataset/601778"}, {"dataset_uid": "601817", "doi": "10.15784/601817", "keywords": "Antarctica; Cryosphere; Wilkes Land", "people": "Kelly, Roger; Dove, Isabel; Robinson, Rebecca", "repository": "USAP-DC", "science_program": null, "title": "Diatom-bound and bulk sedimentary nitrogen isotopes from IODP Site U1357", "url": "https://www.usap-dc.org/view/dataset/601817"}], "date_created": "Wed, 28 Jul 2021 00:00:00 GMT", "description": "The chemical composition of diatom fossils in the Southern Ocean provides information about the environmental history of Antarctica, including sea ice extent, biological production, and ocean nutrient distribution. The sea ice zone is an important habitat for a group of diatoms, largely from the genus Chaetoceros, that have a unique life cycle stage under environmental stress, when they produce a structure called a resting spore. Resting spores are meant to reseed the surface ocean when conditions are more favorable. The production of these heavy resting spores tends to remove significant amounts of carbon and silicon, essential nutrients, out of the surface ocean. As a result, this group has the potential to remove carbon from the surface ocean and can impact the sedimentary record scientists use to reconstruct environmental change. This project explores the role of resting spores in the sedimentary record using the nitrogen isotopic signature of these fossils and how those measurements are used to estimate carbon cycle changes. The work will include laboratory incubations of these organisms to answer if and how the chemistry of the resting spores differs from that of a typical diatom cell. The incubation results will be used to evaluate nutrient drawdown in sea ice environments during two contrasting intervals in earth history, the last ice age and the warm Pliocene. This work should have significant impact on how the scientific community considers the impact of seasonal sea ice cover in the Southern Ocean in terms of how it responds to and regulates global climate. The project provides training and research opportunities for undergraduate and graduate students. Ongoing research efforts in Antarctic earth sciences will be disseminated through an interactive display at the home institution. The work proposed here will address uncertainties in how Chaetoceros resting spores record surface nutrient conditions in their nitrogen stable isotopic composition, the relative impact of their specific signal with respect to the full sedimentary assemblage, and their potential to bias or enhance environmental reconstructions in the sea ice zone. Measurements of nitrogen stable isotopes of nitrate, biomass, and diatom-bound nitrogen and silicon-to-nitrogen ratios of individual species grown in the laboratory will be used to quantify how resting spores record nutrient drawdown in the water column and to what degree their signature is biased toward low nutrient conditions. These relationships will be used to inform diatom-bound nitrogen isotope reconstructions of nutrient drawdown from a Pliocene coastal polyna and an open ocean core that spans the last glacial maximum. This proposal capitalizes on the availability of Southern Ocean isolates of Chaetoceros spp. collected in 2017 for the proposed culture work and archived sediment cores and/or existing data. 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": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Amd/Us; USAP-DC; Antarctica; ISOTOPES; MARINE SEDIMENTS; LABORATORY; USA/NSF; NITROGEN; AMD", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Robinson, Rebecca", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "The nitrogen isotopic composition of diatom resting spores in Southern Ocean sediments: A source of bias and/or paleoenvironmental information?", "uid": "p0010234", "west": -180.0}, {"awards": "2031442 Learman, Deric", "bounds_geometry": "POLYGON((-180 -60,-167.5 -60,-155 -60,-142.5 -60,-130 -60,-117.5 -60,-105 -60,-92.5 -60,-80 -60,-67.5 -60,-55 -60,-55 -62,-55 -64,-55 -66,-55 -68,-55 -70,-55 -72,-55 -74,-55 -76,-55 -78,-55 -80,-67.5 -80,-80 -80,-92.5 -80,-105 -80,-117.5 -80,-130 -80,-142.5 -80,-155 -80,-167.5 -80,180 -80,178 -80,176 -80,174 -80,172 -80,170 -80,168 -80,166 -80,164 -80,162 -80,160 -80,160 -78,160 -76,160 -74,160 -72,160 -70,160 -68,160 -66,160 -64,160 -62,160 -60,162 -60,164 -60,166 -60,168 -60,170 -60,172 -60,174 -60,176 -60,178 -60,-180 -60))", "dataset_titles": "Physical and geochemical data from shelf sediments near the Antartic Pennisula", "datasets": [{"dataset_uid": "601607", "doi": "10.15784/601607", "keywords": "Antarctica; Antarctic Peninsula; Grain Size; Grain Size Analysis; Marine Geoscience; Marine Sediments; Organic Matter Geochemistry; Sediment Core Data; Shelf Sediments; Weddell Sea", "people": "Learman, Deric", "repository": "USAP-DC", "science_program": null, "title": "Physical and geochemical data from shelf sediments near the Antartic Pennisula", "url": "https://www.usap-dc.org/view/dataset/601607"}], "date_created": "Wed, 28 Jul 2021 00:00:00 GMT", "description": "Western Antarctica is one of the fastest warming locations on Earth. Its changing climate will lead to an increase in sea-level and will also alter regional water temperature and chemistry. These changes will directly alter the microbes that inhabit the ecosystem. Microbes are the smallest forms of life on Earth, but they are also the most abundant. They drive cycling of essential nutrients, such as carbon and nitrogen that are found in ocean sediments. In this way they form the foundation of the food chain that supports larger and more complex life. However, we do not know much about how different communities of microbes break down sediments in Antarctica and this will influence the chemistry of those waters. This research will determine how communities of microbes on the coastal shelf of Antarctica degrade complex organic sediments using genetic and chemical data. This data will identify the species in the community, what enzymes they are producing and what chemical reactions they are driving. This research will create broader impacts as the data will be used to create in-class activities that improve a student\u2019s data analysis and critical thinking skills. The data will be used in graduate, undergraduate and K-12 classrooms. This research will provide genetic and enzymatic insight into how microbial communities in benthic sediments on the coastal shelf of Antarctica degrade complex organic matter. The current understanding of how benthic microbial communities respond to and then degrade complex organic matter in Antarctica is fragmented. Recent work suggests benthic microbial communities are shaped by organic matter availability. However, those studies were observational and did not directly examine community function. A preliminary study of metagenomic data from western Antarctic marine sediments, indicates a genetic potential for organic matter degradation but functional data was not been collected. Other studies have examined either enzyme activity or metagenomic potential, but few have been able to directly connect the two. To address this gap in knowledge, this study will utilize metagenomics and metatranscriptomics, coupled with microcosm experiments, enzyme assays, and geochemical data. It will examine Antarctic microbial communities from the Ross Sea, the Bransfield Strait and Weddell Sea to document how the relationship between a communities\u2019 enzymatic activity and the genes used to degrade complex organic matter is related to sediment breakdown. The data will expand our current knowledge of microbial genetic potential and provide a solid understanding of enzyme function as it relates to degradation of complex organic matter in those marine sediments. It will thereby improve our understanding of temperature change on the chemistry of Antarctic seawater. 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": 160.0, "geometry": "POINT(-127.5 -70)", "instruments": null, "is_usap_dc": true, "keywords": "ECOSYSTEM FUNCTIONS; USAP-DC; Antarctic Peninsula; BENTHIC; SHIPS; SEDIMENT CHEMISTRY; Amd/Us; AMD; USA/NSF; Weddell Sea", "locations": "Antarctic Peninsula; Weddell Sea", "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Learman, Deric", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e SHIPS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -80.0, "title": "RAPID: Meta-genomic and Transcriptomic Investigation of Complex Organic Matter Degradation in Antarctic Benthic Sediments", "uid": "p0010235", "west": -55.0}, {"awards": "1643345 Popp, Brian; 1643466 Hollibaugh, James", "bounds_geometry": "POLYGON((-78.20206667 -64.03195833,-76.785055836 -64.03195833,-75.368045002 -64.03195833,-73.951034168 -64.03195833,-72.534023334 -64.03195833,-71.1170125 -64.03195833,-69.700001666 -64.03195833,-68.282990832 -64.03195833,-66.865979998 -64.03195833,-65.448969164 -64.03195833,-64.03195833 -64.03195833,-64.03195833 -64.554377497,-64.03195833 -65.076796664,-64.03195833 -65.599215831,-64.03195833 -66.121634998,-64.03195833 -66.644054165,-64.03195833 -67.166473332,-64.03195833 -67.688892499,-64.03195833 -68.211311666,-64.03195833 -68.733730833,-64.03195833 -69.25615,-65.448969164 -69.25615,-66.865979998 -69.25615,-68.282990832 -69.25615,-69.700001666 -69.25615,-71.1170125 -69.25615,-72.534023334 -69.25615,-73.951034168 -69.25615,-75.368045002 -69.25615,-76.785055836 -69.25615,-78.20206667 -69.25615,-78.20206667 -68.733730833,-78.20206667 -68.211311666,-78.20206667 -67.688892499,-78.20206667 -67.166473332,-78.20206667 -66.644054165,-78.20206667 -66.121634998,-78.20206667 -65.599215831,-78.20206667 -65.076796664,-78.20206667 -64.554377497,-78.20206667 -64.03195833))", "dataset_titles": "\"Collaborative research: Chemoautotrophy in Antarctic bacterioplankton communities supported by the oxidation of urea-derived nitrogen\"; Expedition data of LMG1801", "datasets": [{"dataset_uid": "200193", "doi": "Not yet assigned", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "\"Collaborative research: Chemoautotrophy in Antarctic bacterioplankton communities supported by the oxidation of urea-derived nitrogen\"", "url": "https://www.bco-dmo.org/project/775717"}, {"dataset_uid": "200124", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG1801", "url": "https://www.rvdata.us/search/cruise/LMG1801"}], "date_created": "Fri, 18 Dec 2020 00:00:00 GMT", "description": "Part 1: Nitrification is the conversion of ammonium to nitrate by a two-step process involving two different guilds of microorganisms: ammonia- and nitrite-oxidizers. The process is central to the global nitrogen cycle, affecting everything from retention of fertilizer on croplands to removal of excess nitrogen from coastal waters before it can cause blooms of harmful algae. It also produces nitrous oxide, an ozone-destroying, greenhouse gas. The energy derived from both steps of nitrification is used to convert inorganic carbon into microbial biomass. The biomass produced contributes to the overall food web production of the Southern Ocean and may be a particularly important subsidy during winter when low light levels restrict the other major source of biomass, primary production by single-celled plants. This project addresses three fundamental questions about the biology and geochemistry of polar oceans, with a focus on the process of nitrification. The first question the project will address concerns the contribution of chemoautotrophy (based on nitrification) to the overall supply of organic carbon to the food web of the Southern Ocean. Previous measurements indicate that it contributes about 9% to the Antarctic food web on an annual basis, but those measurements did not include the additional production associated with nitrite oxidation. The second question to be addressed is related to the first and concerns the coupling between the steps of the process. The third seeks to determine the significance of the contribution of other sources of nitrogen, (specifically organic nitrogen and urea released by other organisms) to nitrification because these contributions may not be assessed by standard protocols. Measurements made by others suggest that urea in particular might be as important as ammonium to nitrification in polar regions. This project will result in training a postdoctoral researcher and provide undergraduate students opportunities to gain hand-on experience with research on microbial geochemistry. The Palmer LTER (PAL) activities have focused largely on the interaction between ocean climate and the marine food web affecting top predators. Relatively little effort has been devoted to studying processes related to the microbial geochemistry of nitrogen cycling as part of the Palmer Long Term Ecological Research (LTER) program, yet these are a major themes at other sites. This work will contribute substantially to understanding an important aspect of nitrogen cycling and bacterioplankton production in the PAL-LTER study area. The team will be working synergistically and be participating fully in the education and outreach efforts of the Palmer LTER, including making highlights of the findings available for posting to their project web site and participating in any special efforts they have in the area of outreach. Part 2: The proposed work will quantify oxidation rates of 15N supplied as ammonium, urea and nitrite, allowing us to estimate the contribution of urea-derived N and complete nitrification (ammonia to nitrate) to chemoautotrophy and bacterioplankton production in Antarctic coastal waters. The project will compare these estimates to direct measurements of the incorporation of 14C into organic matter the dark for an independent estimate of chemoautotrophy. The team aims to collect samples spanning the water column: from surface water (~10 m), winter water (50-100 m) and circumpolar deep water (\u003e150 m); on a cruise surveying the continental shelf and slope west of the Antarctic Peninsula in the austral summer of 2018. Other samples will be taken to measure the concentrations of nitrate, nitrite, ammonia and urea, for qPCR analysis of the abundance of relevant microorganisms, and for studies of related processes. The project will rely on collaboration with the existing Palmer LTER to ensure that ancillary data (bacterioplankton abundance and production, chlorophyll, physical and chemical variables) will be available. The synergistic activities of this project along with the LTER activities will provide a unique opportunity to assess chemoautotrophy in context of the overall ecosystem?s dynamics- including both primary and secondary production processes.", "east": -64.03195833, "geometry": "POINT(-71.1170125 -66.644054165)", "instruments": null, "is_usap_dc": true, "keywords": "Pal-Lter; NITROGEN; SHIPS; USAP-DC; MARINE ECOSYSTEMS; BACTERIA/ARCHAEA; BIOGEOCHEMICAL CYCLES; Amd/Us; West Antarctic Shelf; USA/NSF; AMD", "locations": "West Antarctic Shelf; Pal-Lter", "north": -64.03195833, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Hollibaugh, James T.; Popp, Brian", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e SHIPS", "repo": "BCO-DMO", "repositories": "BCO-DMO; R2R", "science_programs": null, "south": -69.25615, "title": "Collaborative Research: Chemoautotrophy in Antarctic Bacterioplankton Communities Supported by the Oxidation of Urea-derived Nitrogen", "uid": "p0010150", "west": -78.20206667}, {"awards": "1341736 Adams, Byron", "bounds_geometry": "POLYGON((-177.4099 -84.4661,-177.08229 -84.4661,-176.75468 -84.4661,-176.42707 -84.4661,-176.09946 -84.4661,-175.77185 -84.4661,-175.44424 -84.4661,-175.11663000000001 -84.4661,-174.78902 -84.4661,-174.46141 -84.4661,-174.1338 -84.4661,-174.1338 -84.56828,-174.1338 -84.67045999999999,-174.1338 -84.77264,-174.1338 -84.87482,-174.1338 -84.977,-174.1338 -85.07918,-174.1338 -85.18136,-174.1338 -85.28354,-174.1338 -85.38571999999999,-174.1338 -85.4879,-174.46141 -85.4879,-174.78902 -85.4879,-175.11663000000001 -85.4879,-175.44424 -85.4879,-175.77185 -85.4879,-176.09946 -85.4879,-176.42707 -85.4879,-176.75468 -85.4879,-177.08229 -85.4879,-177.4099 -85.4879,-177.4099 -85.38571999999999,-177.4099 -85.28354,-177.4099 -85.18136,-177.4099 -85.07918,-177.4099 -84.977,-177.4099 -84.87482,-177.4099 -84.77264,-177.4099 -84.67045999999999,-177.4099 -84.56828,-177.4099 -84.4661))", "dataset_titles": "Dataset DS-TAMS: Genetic diversity of Collembola from the Transantarctic Mountains; GenBank accession numbers MN619477 to MN619610; Meteoric 10Be data of soils from the Shackleton Glacier region; Shackleton Glacier region soil water-soluble geochemical data; Shackleton Glacier region water-soluble salt isotopes; Soil invertebrate surveys from the Shackleton Glacier region of Antarctica during the 2017-2018 austral summer", "datasets": [{"dataset_uid": "200258", "doi": "doi:10.6073/pasta/7959821e5f6f8d56d94bb6a26873b3ae", "keywords": null, "people": null, "repository": "EDI", "science_program": null, "title": "Soil invertebrate surveys from the Shackleton Glacier region of Antarctica during the 2017-2018 austral summer", "url": "https://doi.org/10.6073/pasta/7959821e5f6f8d56d94bb6a26873b3ae"}, {"dataset_uid": "200174", "doi": "10.5883/DS-TAMS", "keywords": null, "people": null, "repository": "Barcode of Life Datasystems (BOLD)", "science_program": null, "title": "Dataset DS-TAMS: Genetic diversity of Collembola from the Transantarctic Mountains", "url": "http://dx.doi.org/10.5883/DS-TAMS"}, {"dataset_uid": "200175", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "GenBank accession numbers MN619477 to MN619610", "url": "https://www.ncbi.nlm.nih.gov/nuccore/MN619477"}, {"dataset_uid": "601418", "doi": "10.15784/601418", "keywords": "Antarctica; Geochemistry; Shackleton Glacier", "people": "Gardner, Christopher B.; Lyons, W. Berry; Diaz, Melisa A.", "repository": "USAP-DC", "science_program": null, "title": "Shackleton Glacier region soil water-soluble geochemical data", "url": "https://www.usap-dc.org/view/dataset/601418"}, {"dataset_uid": "601419", "doi": "10.15784/601419", "keywords": "Antarctica; Geochemistry; Nitrate; Shackleton Glacier; Stable Isotopes; Sulfate; Transantarctic Mountains", "people": "Lyons, W. Berry; Gardner, Christopher B.; Diaz, Melisa A.", "repository": "USAP-DC", "science_program": null, "title": "Shackleton Glacier region water-soluble salt isotopes", "url": "https://www.usap-dc.org/view/dataset/601419"}, {"dataset_uid": "601421", "doi": "10.15784/601421", "keywords": "Antarctica; Be-10; Beryllium-10; Cosmogenic Radionuclides; Geochemistry; Geomorphology; Shackleton Glacier; Surface Exposure Dates", "people": "Diaz, Melisa A.", "repository": "USAP-DC", "science_program": null, "title": "Meteoric 10Be data of soils from the Shackleton Glacier region", "url": "https://www.usap-dc.org/view/dataset/601421"}], "date_created": "Mon, 02 Nov 2020 00:00:00 GMT", "description": "The project will characterize the functional, taxonomic, biotic and abiotic drivers of soil ecosystems in the Trans Antarctic Mountains (one of the most remote and harsh terrestrial landscapes on the planet). The work will utilize new high-throughput DNA and RNA sequencing technologies to identify members of the microbial communities and determine if the microbial community structures are independent of local environmental heterogeneities. In addition the project will determine if microbial diversity and function are correlated with time since the last glacial maximum (LGM). The expected results will greatly contribute to our knowledge regarding rates of microbial succession and help define the some of the limits to life and life-maintaining processes on Earth. The project will analyze genomes and RNA derived from these genomes to describe the relationships between biodiversity and ecosystem functioning from soils above and below LGM elevations and to correlate these with the environmental drivers associated with their development during the last ~18,000 years. The team will identify the taxonomic diversity and the functional genetic composition within a broad suite of soil biota and examine their patterns of assembly and distribution within the framework of their geological legacies. The project will mentor participants from undergraduate students to postdoctoral researchers and prepare them to effectively engage in research to meet their career aspirations. The project will contribute to ongoing public education efforts through relationships with K-12 teachers and administrators- to include University-Public School partnerships. Less formal activities include public lecture series and weblogs aimed at providing information on Antarctic polar desert ecosystems to the general public. Targeted classrooms near each PI\u0027s institution will participate in online, real-time discussions about current topics in Antarctic ecosystems research.", "east": -174.1338, "geometry": "POINT(-175.77185 -84.977)", "instruments": null, "is_usap_dc": true, "keywords": "FIELD INVESTIGATION; LABORATORY; AMD; Amd/Us; USA/NSF; TERRESTRIAL ECOSYSTEMS; Transantarctic Mountains; USAP-DC", "locations": "Transantarctic Mountains", "north": -84.4661, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Earth Sciences", "paleo_time": null, "persons": "Adams, Byron; Fierer, Noah; Wall, Diana; Diaz, Melisa A.; Gardner, Christopher B.; Lyons, W. Berry", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "EDI", "repositories": "Barcode of Life Datasystems (BOLD); EDI; NCBI GenBank; USAP-DC", "science_programs": null, "south": -85.4879, "title": "Collaborative Research: The Role of Glacial History on the Structure and Functioning of Ecological Communities in the Shackleton Glacier Region of the Transantarctic Mountains", "uid": "p0010140", "west": -177.4099}, {"awards": "0732711 Smith, Craig; 0732917 McCormick, Michael; 0732450 Van Dover, Cindy; 0732983 Vernet, Maria", "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": "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": "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": "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 Integrated System Science; Antarctic Organisms and Ecosystems; 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": "USAP-DC", "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": "1543450 Countway, Peter", "bounds_geometry": "POLYGON((-66 -63,-65.7 -63,-65.4 -63,-65.1 -63,-64.8 -63,-64.5 -63,-64.2 -63,-63.9 -63,-63.6 -63,-63.3 -63,-63 -63,-63 -63.3,-63 -63.6,-63 -63.9,-63 -64.2,-63 -64.5,-63 -64.8,-63 -65.1,-63 -65.4,-63 -65.7,-63 -66,-63.3 -66,-63.6 -66,-63.9 -66,-64.2 -66,-64.5 -66,-64.8 -66,-65.1 -66,-65.4 -66,-65.7 -66,-66 -66,-66 -65.7,-66 -65.4,-66 -65.1,-66 -64.8,-66 -64.5,-66 -64.2,-66 -63.9,-66 -63.6,-66 -63.3,-66 -63))", "dataset_titles": "Biogenic Sulfur Samples from Station E (Palmer Station, Antarctica) and Associated Incubation Experiments; Dissolved Inorganic Nutrient Samples from Station E (Palmer Station, Antarctica) and Associated Incubation Experiments ; Dissolved Organic Carbon (DOC) and Total Dissolved Nitrogen (TDN) Samples from Station E (Palmer Station, Antarctica) and Associated Incubation Experiments; Flow Cytometry Samples from Station E (Palmer Station, Antarctica) and Associated Incubation Experiments; Heterotrophic Bacterial Production Samples from Station E (Palmer Station, Antarctica) and Associated Incubation Experiments; Western Antarctic Peninsula plankton raw sequence reads", "datasets": [{"dataset_uid": "200337", "doi": "", "keywords": null, "people": null, "repository": "GenBank", "science_program": null, "title": "Western Antarctic Peninsula plankton raw sequence reads", "url": "https://dataview.ncbi.nlm.nih.gov/object/PRJNA870587?reviewer=bmud2tbbrqbus79i2n2hb83uio"}, {"dataset_uid": "601645", "doi": "10.15784/601645", "keywords": "Antarctica; Nitrate; Nitrite; Palmer Station; Phosphate", "people": "Countway, Peter; Matrai, Patricia", "repository": "USAP-DC", "science_program": null, "title": "Dissolved Inorganic Nutrient Samples from Station E (Palmer Station, Antarctica) and Associated Incubation Experiments ", "url": "https://www.usap-dc.org/view/dataset/601645"}, {"dataset_uid": "601647", "doi": "10.15784/601647", "keywords": "Antarctica; Palmer Station; Phytoplankton", "people": "Countway, Peter; Matrai, Patricia", "repository": "USAP-DC", "science_program": null, "title": "Flow Cytometry Samples from Station E (Palmer Station, Antarctica) and Associated Incubation Experiments", "url": "https://www.usap-dc.org/view/dataset/601647"}, {"dataset_uid": "601646", "doi": "10.15784/601646", "keywords": "Antarctica; Carbon; Dissolved Organic Carbon; Nitrogen; Palmer Station; TDN; Total Dissolved Nitrogen", "people": "Matrai, Patricia; Countway, Peter", "repository": "USAP-DC", "science_program": null, "title": "Dissolved Organic Carbon (DOC) and Total Dissolved Nitrogen (TDN) Samples from Station E (Palmer Station, Antarctica) and Associated Incubation Experiments", "url": "https://www.usap-dc.org/view/dataset/601646"}, {"dataset_uid": "601648", "doi": "10.15784/601648", "keywords": "Antarctica; Biota; Dimethyl Sulfide; Dimethylsulfoniopropionate; Dimethylsulfoxide; DMSP; DMSP Lyase; Palmer Station", "people": "Matrai, Patricia; Countway, Peter", "repository": "USAP-DC", "science_program": null, "title": "Biogenic Sulfur Samples from Station E (Palmer Station, Antarctica) and Associated Incubation Experiments", "url": "https://www.usap-dc.org/view/dataset/601648"}, {"dataset_uid": "601644", "doi": "10.15784/601644", "keywords": "3H-Leu; Antarctica; Bacteria; Biota; DMSP; Heterotrophic Bacterial Production; Palmer Station", "people": "Matrai, Patricia; Countway, Peter", "repository": "USAP-DC", "science_program": null, "title": "Heterotrophic Bacterial Production Samples from Station E (Palmer Station, Antarctica) and Associated Incubation Experiments", "url": "https://www.usap-dc.org/view/dataset/601644"}], "date_created": "Sat, 01 Aug 2020 00:00:00 GMT", "description": "The Southern Ocean in the vicinity of Antarctica is a region characterized by seasonally-driven marine phytoplankton blooms that are often dominated by microalgal species which produce large amounts of dimethylsulfoniopropionate (DMSP). DMSP can be converted to the compound dimethylsulfide (DMS) which is a molecule that can escape into the atmosphere where it is known to have strong condensation properties that are involved in regional cloud formation. Production of DMSP can influence the diversity and composition of microbial assemblages in seawater and the types and activities of microbes in the seawater will likely affect the magnitude of DMSP\\DMS production. The proposal aims to examine the role of DMSP in structuring the microbial communities in Antarctic waters and how this structuring may influence DMSP cycling. The project will leverage the Antarctic research to introduce concepts and data linking microbial diversity and biogeochemistry to a range of audiences (including high school and undergraduate students in Maine). The project will also engage teacher and students in rural K-8 schools and will allow a collaboration with a science writer and illustrator who will join the team in the field. The writer will use the southern ocean experience as the setting for a poster and a book about the proposed research and the scientists studying extreme environments. The project will examine (1) the extent to which the cycling of DMSP in southern ocean waters influences the composition and diversity of bacterial and protistan assemblages; (2) conversely, whether the composition and diversity of southern ocean protistan and bacterial assemblages influence the magnitude and rates of DMSP cycling; (3) the expression of DMSP degradation genes by marine bacteria seasonally and in response to additions of DMSP; and, to synthesize these results by quantifying (4) the microbial networks resulting from the presence of DMSP-producers and DMSP-consumers along with their predators, all involved in the cycling of DMSP in southern ocean waters. The work will be accomplished by conducting continuous growth experiments with DMSP-amended natural samples during field sampling of different microbial communities present in summer and fall. Data from the molecular (such as 16S/ 18S tag sequences, DMSP-cycle gene transcripts) and biogeochemical (such as biogenic sulfur cycling, bacterial production, microbial biomass) investigations will be integrated via network analysis.", "east": -63.0, "geometry": "POINT(-64.5 -64.5)", "instruments": null, "is_usap_dc": true, "keywords": "USAP-DC; COMMUNITY DYNAMICS; FIELD INVESTIGATION; AMD; PLANKTON; Amd/Us; BIOGEOCHEMICAL CYCLES; Palmer Station; USA/NSF", "locations": "Palmer Station", "north": -63.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Countway, Peter", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "GenBank", "repositories": "GenBank; USAP-DC", "science_programs": null, "south": -66.0, "title": "Microbial Community Structure and Expression of Functional Genes Involved in the Seasonal Cycling of DMSP in the Southern Ocean", "uid": "p0010120", "west": -66.0}, {"awards": "1543396 Christner, Brent; 1543453 Lyons, W. Berry; 1543537 Priscu, John; 1543441 Fricker, Helen; 1543347 Rosenheim, Brad; 1543405 Leventer, Amy", "bounds_geometry": "POLYGON((-163.611 -84.33543,-162.200034 -84.33543,-160.789068 -84.33543,-159.378102 -84.33543,-157.967136 -84.33543,-156.55617 -84.33543,-155.145204 -84.33543,-153.734238 -84.33543,-152.323272 -84.33543,-150.912306 -84.33543,-149.50134 -84.33543,-149.50134 -84.3659157,-149.50134 -84.3964014,-149.50134 -84.4268871,-149.50134 -84.4573728,-149.50134 -84.4878585,-149.50134 -84.5183442,-149.50134 -84.5488299,-149.50134 -84.5793156,-149.50134 -84.6098013,-149.50134 -84.640287,-150.912306 -84.640287,-152.323272 -84.640287,-153.734238 -84.640287,-155.145204 -84.640287,-156.55617 -84.640287,-157.967136 -84.640287,-159.378102 -84.640287,-160.789068 -84.640287,-162.200034 -84.640287,-163.611 -84.640287,-163.611 -84.6098013,-163.611 -84.5793156,-163.611 -84.5488299,-163.611 -84.5183442,-163.611 -84.4878585,-163.611 -84.4573728,-163.611 -84.4268871,-163.611 -84.3964014,-163.611 -84.3659157,-163.611 -84.33543))", "dataset_titles": "Antarctica - PI Continuous - GZ01-WIS_GroundingZone_01 P.S. - GPS/GNSS Observations Dataset; Antarctica - PI Continuous - GZ13-WIS_GroundingZone_13 P.S. - GPS/GNSS Observations Dataset; Antarctica - PI Continuous - LA02-WIS_LAKES_02 P.S. - GPS/GNSS Observations Dataset; Antarctica - PI Continuous - LA06-WIS_LAKES_06 P.S. - GPS/GNSS Observations Dataset; Antarctica - PI Continuous - LA07-WIS_LAKES_07 P.S. - GPS/GNSS Observations Dataset; Antarctica - PI Continuous - LA09-WIS_LAKES_09 P.S. - GPS/GNSS Observations Dataset; Bistatic Radar Sounding of Whillans Ice Stream, Antarctica and Store Glacier, Greenland; CTD data from Mercer Subglacial Lake and access borehole; Discrete bulk sediment properties data from Mercer Subglacial Lake; Isotopic data from Whillans Ice Stream grounding zone, West Antarctica; Mercer Subglacial Lake radiocarbon and stable isotope data ; Mercer Subglacial Lake (SLM) microbial composition: 16S rRNA genes (Sequence Read Archive; BioProject: PRJNA790995); Mercer Subglacial Lake (SLM) noble gas and isotopic data; Mercer Subglacial Lake water column viral metagenomic sequencing; Salsa sediment cores; Sediment porewater properties data from Mercer Subglacial Lake; Water column biogeochemical data from Mercer Subglacial Lake", "datasets": [{"dataset_uid": "200215", "doi": "10.7283/C503-KS23", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "Antarctica - PI Continuous - LA06-WIS_LAKES_06 P.S. - GPS/GNSS Observations Dataset", "url": "https://www.unavco.org/data/doi/10.7283/C503-KS23"}, {"dataset_uid": "200212", "doi": "10.7283/PT0Q-JB95", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "Antarctica - PI Continuous - GZ01-WIS_GroundingZone_01 P.S. - GPS/GNSS Observations Dataset", "url": "https://www.unavco.org/data/doi/10.7283/PT0Q-JB95"}, {"dataset_uid": "200213", "doi": "10.7283/F7BB-JH05", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "Antarctica - PI Continuous - GZ13-WIS_GroundingZone_13 P.S. - GPS/GNSS Observations Dataset", "url": "https://www.unavco.org/data/doi/10.7283/F7BB-JH05"}, {"dataset_uid": "200214", "doi": "10.7283/YW8Z-TK03", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "Antarctica - PI Continuous - LA02-WIS_LAKES_02 P.S. - GPS/GNSS Observations Dataset", "url": "https://www.unavco.org/data/doi/10.7283/YW8Z-TK03"}, {"dataset_uid": "200216", "doi": "10.7283/F8NH-CV04", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "Antarctica - PI Continuous - LA07-WIS_LAKES_07 P.S. - GPS/GNSS Observations Dataset", "url": "https://www.unavco.org/data/doi/10.7283/F8NH-CV04"}, {"dataset_uid": "601498", "doi": "10.15784/601498", "keywords": "Antarctica; Mercer Subglacial Lake; Noble Gas", "people": "Lyons, W. Berry; Gardner, Christopher B.", "repository": "USAP-DC", "science_program": null, "title": "Mercer Subglacial Lake (SLM) noble gas and isotopic data", "url": "https://www.usap-dc.org/view/dataset/601498"}, {"dataset_uid": "200282", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Mercer Subglacial Lake (SLM) microbial composition: 16S rRNA genes (Sequence Read Archive; BioProject: PRJNA790995)", "url": "https://www.ncbi.nlm.nih.gov/bioproject/?term=PRJNA790995"}, {"dataset_uid": "601657", "doi": "10.15784/601657", "keywords": "Antarctica; Conductivity; CTD; Depth; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Hot Water Drill; Mercer Subglacial Lake; Physical Properties; SALSA; Subglacial Lake; Temperature", "people": "Priscu, John; Rosenheim, Brad; Leventer, Amy; Dore, John", "repository": "USAP-DC", "science_program": null, "title": "CTD data from Mercer Subglacial Lake and access borehole", "url": "https://www.usap-dc.org/view/dataset/601657"}, {"dataset_uid": "200246", "doi": "", "keywords": null, "people": null, "repository": "OSU-MGR", "science_program": null, "title": "Salsa sediment cores", "url": "https://osu-mgr.org"}, {"dataset_uid": "601360", "doi": "10.15784/601360", "keywords": "Antarctica; Radiocarbon; Sediment; Whillans Ice Stream", "people": "Venturelli, Ryan A", "repository": "USAP-DC", "science_program": "WISSARD", "title": "Isotopic data from Whillans Ice Stream grounding zone, West Antarctica", "url": "https://www.usap-dc.org/view/dataset/601360"}, {"dataset_uid": "601672", "doi": "10.15784/601672", "keywords": "Antarctica; Isotope; Mercer Subglacial Lake; Radiocarbon; Subglacial Lake", "people": "Venturelli, Ryan; Rosenheim, Brad", "repository": "USAP-DC", "science_program": null, "title": "Mercer Subglacial Lake radiocarbon and stable isotope data ", "url": "https://www.usap-dc.org/view/dataset/601672"}, {"dataset_uid": "200342", "doi": null, "keywords": null, "people": null, "repository": "GenBank", "science_program": null, "title": "Mercer Subglacial Lake water column viral metagenomic sequencing", "url": "https://www.ncbi.nlm.nih.gov/biosample/32811410"}, {"dataset_uid": "200217", "doi": "10.7283/3JMY-Y504", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "Antarctica - PI Continuous - LA09-WIS_LAKES_09 P.S. - GPS/GNSS Observations Dataset", "url": "https://www.unavco.org/data/doi/10.7283/3JMY-Y504"}, {"dataset_uid": "601664", "doi": "10.15784/601664", "keywords": "Antarctica; Gas; Geochemistry; Glacier; Glaciology; Mercer Subglacial Lake; Methane; SALSA; Sediment Core; West Antarctic Ice Sheet", "people": "Michaud, Alexander; Dore, John; Science Team, SALSA; Steigmeyer, August; Tranter, Martyn; Skidmore, Mark", "repository": "USAP-DC", "science_program": null, "title": "Sediment porewater properties data from Mercer Subglacial Lake", "url": "https://www.usap-dc.org/view/dataset/601664"}, {"dataset_uid": "601663", "doi": "10.15784/601663", "keywords": "Antarctica; Carbon; Cell Counts; Geochemistry; Glacier; Glaciers/ice Sheet; Glaciers/Ice Sheet; Mercer Subglacial Lake; Microbes; Nutrients; SALSA; Stable Isotopes; Trace Elements; West Antarctic Ice Sheet", "people": "Steigmeyer, August; Hawkings, Jon; Skidmore, Mark; Dore, John; Science Team, SALSA; Priscu, John; Tranter, Martyn; Barker, Joel; Li, Wei", "repository": "USAP-DC", "science_program": null, "title": "Water column biogeochemical data from Mercer Subglacial Lake", "url": "https://www.usap-dc.org/view/dataset/601663"}, {"dataset_uid": "601661", "doi": "10.15784/601661", "keywords": "Antarctica; Carbon; Glacier; Glaciers/ice Sheet; Glaciers/Ice Sheet; Iron; Mercer Subglacial Lake; Mineralogy; Particle Size; Physical Properties; SALSA; Sediment Core; Sulfur; West Antarctic Ice Sheet", "people": "Campbell, Timothy; Dore, John; Michaud, Alexander; Hawkings, Jon; Skidmore, Mark; Tranter, Martyn; Venturelli, Ryan A; Science Team, SALSA", "repository": "USAP-DC", "science_program": null, "title": "Discrete bulk sediment properties data from Mercer Subglacial Lake", "url": "https://www.usap-dc.org/view/dataset/601661"}, {"dataset_uid": "601472", "doi": "10.15784/601472", "keywords": "Antarctica; Bistatic Radar; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPS Data; Greenland; Lake Whillans; Radar; Store Glacier; Whillans Ice Stream; WISSARD", "people": "Christoffersen, Poul; Peters, Sean; Bienert, Nicole; Siegfried, Matthew; Schroeder, Dustin; Dawson, Eliza; MacKie, Emma", "repository": "USAP-DC", "science_program": "WISSARD", "title": "Bistatic Radar Sounding of Whillans Ice Stream, Antarctica and Store Glacier, Greenland", "url": "https://www.usap-dc.org/view/dataset/601472"}], "date_created": "Thu, 16 Jul 2020 00:00:00 GMT", "description": "The Antarctic subglacial environment remains one of the least explored regions on Earth. This project will examine the physical and biological characteristics of Subglacial Lake Mercer, a lake that lies 1200m beneath the West Antarctic Ice Sheet. This study will address key questions relating to the stability of the ice sheet, the subglacial hydrological system, and the deep-cold subglacial biosphere. The education and outreach component aims to widely disseminate results to the scientific community and to the general public through short films, a blog, and a website. Subglacial Lake Mercer is one of the larger hydrologically active lakes in the southern basin of the Whillans Ice Plain, West Antarctica. It receives about 25 percent of its water from East Antarctica with the remainder originating from West Antarctica, is influenced by drain/fill cycles in a lake immediately upstream (Subglacial Lake Conway), and lies about 100 km upstream of the present grounding line of the Ross Ice Shelf. This site will yield information on the history of the Whillans and Mercer Ice Streams, and on grounding line migration. The integrated study will include direct sampling of basal ice, water, and sediment from the lake in concert with surface geophysical surveys over a three-year period to define the hydrological connectivity among lakes on the Whillans Ice Plain and their flow paths to the sea. The geophysical surveys will furnish information on subglacial hydrology, aid the site selection for hot-water drilling, and provide spatial context for interpreting findings. The hot-water-drilled boreholes will be used to collect basal ice samples, provide access for direct measurement of subglacial physical, chemical, and biological conditions in the water column and sediments, and to explore the subglacial water cavities using a remotely operated vehicle equipped with sensors, cameras, and sampling equipment. Data collected from this study will address the overarching hypothesis \"Contemporary biodiversity and carbon cycling in hydrologically-active subglacial environments associated with the Mercer and Whillans ice streams are regulated by the mineralization and cycling of relict marine organic matter and through interactions among ice, rock, water, and sediments\". The project will be undertaken by a collaborative team of scientists, with expertise in microbiology, biogeochemistry, hydrology, geophysics, glaciology, marine geology, paleoceanography, and science communication.", "east": -149.50134, "geometry": "POINT(-156.55617 -84.4878585)", "instruments": null, "is_usap_dc": true, "keywords": "SEDIMENTS; Antarctica; ISOTOPES; Subglacial Lake; USAP-DC; VIRUSES; PALEOCLIMATE RECONSTRUCTIONS; BACTERIA/ARCHAEA; LABORATORY; Radiocarbon; Whillans Ice Stream; AMD; SALSA; ECOSYSTEM FUNCTIONS; RADIOCARBON; FIELD INVESTIGATION; ICE MOTION; Mercer Ice Stream; Amd/Us; USA/NSF; GLACIERS/ICE SHEETS", "locations": "Antarctica; Mercer Ice Stream; Whillans Ice Stream", "north": -84.33543, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Integrated System Science; Antarctic Glaciology; Antarctic Integrated System Science; Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology; Antarctic Instrumentation and Support; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science", "paleo_time": null, "persons": "Rosenheim, Brad; Fricker, Helen; Priscu, John; Leventer, Amy; Dore, John; Lyons, W. Berry; Christner, Brent", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "UNAVCO", "repositories": "GenBank; NCBI GenBank; OSU-MGR; UNAVCO; USAP-DC", "science_programs": null, "south": -84.640287, "title": "Collaborative Research: Subglacial Antarctic Lakes Scientific Access (SALSA): Integrated Study of Carbon Cycling in Hydrologically-active Subglacial Environments", "uid": "p0010119", "west": -163.611}, {"awards": "1341432 Brzezinski, Mark; 1341464 Robinson, Rebecca", "bounds_geometry": "POLYGON((-175 -54,-174 -54,-173 -54,-172 -54,-171 -54,-170 -54,-169 -54,-168 -54,-167 -54,-166 -54,-165 -54,-165 -55.3,-165 -56.6,-165 -57.9,-165 -59.2,-165 -60.5,-165 -61.8,-165 -63.1,-165 -64.4,-165 -65.7,-165 -67,-166 -67,-167 -67,-168 -67,-169 -67,-170 -67,-171 -67,-172 -67,-173 -67,-174 -67,-175 -67,-175 -65.7,-175 -64.4,-175 -63.1,-175 -61.8,-175 -60.5,-175 -59.2,-175 -57.9,-175 -56.6,-175 -55.3,-175 -54))", "dataset_titles": "Diatom assemblage counts from NBP17-02 shipboard carboy experiments; Dissolved nutrient profiles from along 170\u00b0W between 67 and 54\u00b0S; Expedition Data of NBP1702; Particle composition measurements from along 170\u00b0W between 67-54\u00b0S; Particulate silicon and nitrogen concentrations and isotopic composition measurements in McLane pump profiles from 67\u00b0S to 55\u00b0S latitude in the Pacific Sector of the Southern Ocean; Silicon concentration and isotopic composition measurements in pore waters and sediments from 67\u00b0S to 55\u00b0S latitude in the Pacific Sector of the Southern Ocean; Surface Southern Ocean community growouts to evaluate the diatom bound N isotope proxy", "datasets": [{"dataset_uid": "601522", "doi": "10.15784/601522", "keywords": "Antarctica; Nitrogen Isotopes; Oceans; Paleoproxies; Southern Ocean", "people": "Robinson, Rebecca; Jones, Colin; Brzezinski, Mark; Riesselman, Christina; Kelly, Roger; Closset, Ivia; Robinson, Rebecca ", "repository": "USAP-DC", "science_program": null, "title": "Surface Southern Ocean community growouts to evaluate the diatom bound N isotope proxy", "url": "https://www.usap-dc.org/view/dataset/601522"}, {"dataset_uid": "200126", "doi": "10.7284/907211", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data of NBP1702", "url": "https://www.rvdata.us/search/cruise/NBP1702"}, {"dataset_uid": "601523", "doi": "10.15784/601523", "keywords": "Antarctica; Biota; Carboy Growouts; Diatom; Diatom Assemblage Data; NBP1702; Oceans; R/v Nathaniel B. Palmer; Southern Ocean; Southern Ocean Summer", "people": "Robinson, Rebecca; Riesselman, Christina; Robinson, Rebecca ; Jones, Colin", "repository": "USAP-DC", "science_program": null, "title": "Diatom assemblage counts from NBP17-02 shipboard carboy experiments", "url": "https://www.usap-dc.org/view/dataset/601523"}, {"dataset_uid": "601269", "doi": "10.15784/601269", "keywords": "Antarctica; Chlorophyll; Southern Ocean", "people": "Brzezinski, Mark; Robinson, Rebecca", "repository": "USAP-DC", "science_program": null, "title": "Dissolved nutrient profiles from along 170\u00b0W between 67 and 54\u00b0S", "url": "https://www.usap-dc.org/view/dataset/601269"}, {"dataset_uid": "601276", "doi": "10.15784/601276", "keywords": "Antarctica; Biogenic Silica; Nitrogen Isotopes; Southern Ocean", "people": "Robinson, Rebecca; Brzezinski, Mark", "repository": "USAP-DC", "science_program": null, "title": "Particle composition measurements from along 170\u00b0W between 67-54\u00b0S", "url": "https://www.usap-dc.org/view/dataset/601276"}, {"dataset_uid": "601562", "doi": "10.15784/601562", "keywords": "Antarctica; Biogenic Silica; Chemistry:sediment; Chemistry:Sediment; Lithogenic Silica; Marine Geoscience; NBP1702; Pore Water Biogeochemistry; Sediment; Silicon Cycle; Silicon Stable Isotope; Southern Ocean", "people": "Jones, Janice L.; Brzezinski, Mark; Closset, Ivia", "repository": "USAP-DC", "science_program": null, "title": "Silicon concentration and isotopic composition measurements in pore waters and sediments from 67\u00b0S to 55\u00b0S latitude in the Pacific Sector of the Southern Ocean", "url": "https://www.usap-dc.org/view/dataset/601562"}, {"dataset_uid": "601576", "doi": "10.15784/601576", "keywords": "Antarctica; Biogenic Silica; Chemistry:sediment; Chemistry:Sediment; Diatom; Diatom Bound; Lithogenic Silica; Marine Geoscience; NBP1702; Nitrogen Isotopes; Silicon Cycle; Silicon Stable Isotope; Southern Ocean", "people": "Robinson, Rebecca; Jones, Janice L.; Closset, Ivia; Brzezinski, Mark", "repository": "USAP-DC", "science_program": null, "title": " Particulate silicon and nitrogen concentrations and isotopic composition measurements in McLane pump profiles from 67\u00b0S to 55\u00b0S latitude in the Pacific Sector of the Southern Ocean", "url": "https://www.usap-dc.org/view/dataset/601576"}], "date_created": "Wed, 26 Feb 2020 00:00:00 GMT", "description": "Collaborative Proposal: A field and laboratory examination of the diatom N and Si isotope proxies: Implications for assessing the Southern Ocean biological pump The rise in atmospheric carbon dioxide concentrations and associated climate changes make understanding the role of the ocean in large scale carbon cycle a priority. Geologic samples allow exploration of potential mechanisms for carbon dioxide drawdown during glacial periods through the use of geochemical proxies. Nitrogen and silicon isotope signatures from fossil diatoms (microscopic plants) are used to investigate changes in the physical supply and biological demand for nutrients (like nitrogen and silicon and carbon) in the Southern Ocean. The project will evaluate the use the nitrogen and silicon isotope proxies through a series of laboratory experiments and Southern Ocean field sampling. The results will provide quantification of real relationships between nitrogen and silicon isotopes and nutrient usage in the Southern Ocean and allow exploration of the role of other factors, including biological diversity, ice cover, and mixing, in altering the chemical signatures recorded by diatoms. Seafloor sediment samples will be used to evaluate how well the signal created in the water column is recorded by fossil diatoms buried in the seafloor. Improving the nutrient isotope proxies will allow for a more quantitative understanding of the role of polar biology in regulating natural variation in atmospheric carbon dioxide. The project will also result in the training of a graduate student and development of outreach materials targeting a broad popular audience. This project seeks to test the fidelity of the diatom nitrogen and silicon isotope proxies, two commonly used paleoceanographic tools for investigating the role of the Southern Ocean biological pump in regulating atmospheric CO2 concentrations on glacial-interglacial timescales. Existing ground-truthing data, including culture experiments, surface sediment data and downcore reconstructions, all suggest that nutrient utilization is the primary driver of isotopic variation in the Southern Ocean. However, strong contribution of interspecific variation is implied by recent culture results. Moreover, field and laboratory studies present some contradictory results in terms of the relative importance of interspecific variation and of inferred post-depositional alteration of the nutrient isotope signals. Here, a first order test of the N and Si diatom nutrient isotope paleo-proxies, involving water column dissolved and particulate sampling and laboratory culturing of field-isolates, is proposed. Southern Ocean water, biomass, live diatoms and fossil diatom sampling will be conducted to investigate species and assemblage related variability in diatom nitrogen and silicon isotopes and their relationship to surface nutrient fields and early diagenesis. Access to fresh materials produced in an analogous environmental context to the sediments of primary interest is critical for making robust paleoceanographic reconstructions. Field sampling will occur along 175\u00b0W, transecting the Antarctic Circumpolar Current from the subtropics to the marginal ice edge. Collection of water, sinking/suspended particles and multi-core samples from 13 stations and 3 shipboard incubation experiments will be used to test four proposed hypotheses that together evaluate the significance of existing culture results and seek to allow the best use of diatom nutrient isotope proxies in evaluating the biological pump.", "east": -165.0, "geometry": "POINT(-170 -60.5)", "instruments": null, "is_usap_dc": true, "keywords": "Southern Ocean; AMD; NITROGEN ISOTOPES; R/V NBP; NSF/USA; NUTRIENTS; USAP-DC; Amd/Us", "locations": "Southern Ocean", "north": -54.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Robinson, Rebecca; Brzezinski, Mark", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "USAP-DC", "repositories": "R2R; USAP-DC", "science_programs": null, "south": -67.0, "title": "Collaborative Proposal: A Field and Laboratory Examination of the Diatom N and Si Isotope Proxies: Implications for Assessing the Southern Ocean Biological Pump", "uid": "p0010083", "west": -175.0}, {"awards": "1443105 Steig, Eric", "bounds_geometry": "POINT(0 -90)", "dataset_titles": "Continuous-flow measurements of the complete water isotope ratios (D/H, 17O/16O, 18O/16) from the South Pole ice core; South Pole high resolution ice core water stable isotope record for dD, d18O; South Pole Ice Core Holocene Major Ion Dataset; South Pole Ice Core Sea Salt and Major Ions; SP19 Gas Chronology; Temperature, accumulation rate, and layer thinning from the South Pole ice core (SPC14)", "datasets": [{"dataset_uid": "601850", "doi": "10.15784/601850", "keywords": "Antarctica; Cryosphere; Glaciology; Ice Core; Ice Core Chemistry; Ice Core Records; Major Ion; Sea Ice; Sea Salt; Sodium; South Pole; SPICEcore", "people": "Winski, Dominic A.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole Ice Core Holocene Major Ion Dataset", "url": "https://www.usap-dc.org/view/dataset/601850"}, {"dataset_uid": "601239", "doi": "10.15784/601239", "keywords": "Antarctica; Cavity Ring Down Spectrometers; Delta 18O; Delta Deuterium; Deuterium Isotopes; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice; Ice Core; Ice Core Chemistry; Ice Core Data; Oxygen Isotope; Snow/ice; Snow/Ice; Stable Isotopes", "people": "Jones, Tyler R.; Vaughn, Bruce; Kahle, Emma; Steig, Eric J.; Schauer, Andrew; Morris, Valerie; White, James", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole high resolution ice core water stable isotope record for dD, d18O", "url": "https://www.usap-dc.org/view/dataset/601239"}, {"dataset_uid": "601851", "doi": "10.15784/601851", "keywords": "Antarctica; Cryosphere; Glaciology; Ice Core; Ice Core Chemistry; Ice Core Records; Major Ion; Sea Ice; Sea Salt; Sodium; South Pole; SPICEcore", "people": "Winski, Dominic A.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole Ice Core Sea Salt and Major Ions", "url": "https://www.usap-dc.org/view/dataset/601851"}, {"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": "601396", "doi": "10.15784/601396", "keywords": "Accumulation; Antarctica; Diffusion Length; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Ice Dynamic; Layer Thinning; Oxygen Isotope; South Pole; SPICEcore; Temperature", "people": "Jones, Tyler R.; Kahle, Emma; Steig, Eric J.; White, James; Epifanio, Jenna; Buizert, Christo; Waddington, Edwin D.; Conway, Howard; Stevens, Max; Schauer, Andrew; Vaughn, Bruce; Morris, Valerie; Koutnik, Michelle; Fudge, T. J.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "Temperature, accumulation rate, and layer thinning from the South Pole ice core (SPC14)", "url": "https://www.usap-dc.org/view/dataset/601396"}, {"dataset_uid": "601429", "doi": "10.15784/601429", "keywords": "Antarctica; Climate; Deuterium; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Hydrogen; Ice; Ice Core; Ice Core Chemistry; Oxygen; Paleoclimate; Snow/ice; Snow/Ice; South Pole; Stable Isotopes", "people": "Vaughn, Bruce; Jones, Tyler R.; White, James; Morris, Valerie; Schauer, Andrew; Steig, Eric J.; Kahle, Emma", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "Continuous-flow measurements of the complete water isotope ratios (D/H, 17O/16O, 18O/16) from the South Pole ice core", "url": "https://www.usap-dc.org/view/dataset/601429"}], "date_created": "Sun, 17 Nov 2019 00:00:00 GMT", "description": "This project will develop a record of the stable-isotope ratios of water from an ice core at the South Pole, Antarctica. Water-isotope ratio measurements provide a means to determine variability in temperature through time. South Pole is distinct from most other locations in Antarctica in showing no warming in recent decades, but little is known about temperature variability in this location prior to the installation of weather stations in 1957. The measurements made as part of this project will result in a much longer temperature record, extending at least 40,000 years, aiding our ability to understand what controls Antarctic climate, and improving projections of future Antarctic climate change. Data from this project will be critical to other investigators working on the South Pole ice core, and of general interest to other scientists and the public. Data will be provided rapidly to other investigators and made public as soon as possible. This project will obtain records of the stable-isotope ratios of water on the ice core currently being obtained at South Pole. The core will reach a depth of 1500 m and an age of 40,000 years. The project will use laser spectroscopy to obtain both an ultra-high-resolution record of oxygen 18/16 and deuterium-hydrogen ratios, and a lower-resolution record of oxygen 17/16 ratios. The high-resolution measurements will be used to aid in dating the core, and to provide estimates of isotope diffusion that constrain the process of firn densification. The novel 17/16 measurement provides additional constraints on the isotope fractionation due to the temperature-dependent supersaturation ratio, which affects the fractionation of water during the liquid-solid condensate transition. Together, these techniques will allow for improved accuracy in the use of the water isotope ratios as proxies for ice-sheet temperature, sea-surface temperature, and atmospheric circulation. The result will be a record of decadal through centennial and millennial scale climate change in a climatically distinct region in East Antarctica that has not been previously sampled by deep ice coring. The project will support a graduate student who will be co-advised by faculty at the University of Washington and the University of Colorado, and will be involved in all aspects of the work.", "east": 0.0, "geometry": "POINT(0 -90)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS", "is_usap_dc": true, "keywords": "SPICEcore; D18O; LABORATORY; OXYGEN ISOTOPE ANALYSIS; Oxygen Isotope; South Pole; USAP-DC; GLACIERS/ICE SHEETS; Antarctica; AMD; FIELD INVESTIGATION; Ice Core", "locations": "Antarctica; South Pole", "north": -90.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE", "persons": "Steig, Eric J.; White, James", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "SPICEcore", "south": -90.0, "title": "Collaborative Research: Record of the Triple-oxygen Isotope and Hydrogen Isotope Composition of Ice from an Ice Core at South Pole", "uid": "p0010065", "west": 0.0}, {"awards": "1141839 Steig, Eric; 1142646 Twickler, Mark; 1142517 Aydin, Murat", "bounds_geometry": "POINT(90 -90)", "dataset_titles": "South Pole Ice Core Holocene Major Ion Dataset; South Pole Ice Core Sea Salt and Major Ions; South Pole ice core (SPC14) discrete methane data; South Pole Ice Core (SPICEcore) SPC14 Core Quality Versus Depth; SP19 Gas Chronology; Temperature, accumulation rate, and layer thinning from the South Pole ice core (SPC14)", "datasets": [{"dataset_uid": "601850", "doi": "10.15784/601850", "keywords": "Antarctica; Cryosphere; Glaciology; Ice Core; Ice Core Chemistry; Ice Core Records; Major Ion; Sea Ice; Sea Salt; Sodium; South Pole; SPICEcore", "people": "Winski, Dominic A.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole Ice Core Holocene Major Ion Dataset", "url": "https://www.usap-dc.org/view/dataset/601850"}, {"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": "Winski, Dominic A.; Epifanio, Jenna; Brook, Edward J.; Buizert, Christo; Kreutz, Karl; Aydin, Murat; Edwards, Jon S.; Sowers, Todd A.; Kahle, Emma; Steig, Eric J.; Osterberg, Erich; Fudge, T. J.; Hood, Ekaterina; Kalk, Michael; Ferris, David G.; Kennedy, Joshua A.; 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": "601851", "doi": "10.15784/601851", "keywords": "Antarctica; Cryosphere; Glaciology; Ice Core; Ice Core Chemistry; Ice Core Records; Major Ion; Sea Ice; Sea Salt; Sodium; South Pole; SPICEcore", "people": "Winski, Dominic A.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole Ice Core Sea Salt and Major Ions", "url": "https://www.usap-dc.org/view/dataset/601851"}, {"dataset_uid": "601221", "doi": "10.15784/601221", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice; Ice Core Data; Ice Core Depth; Ice Core Records; Snow/ice; Snow/Ice; SPICEcore", "people": "Steig, Eric J.; Nunn, Richard; Hargreaves, Geoff; Fudge, T. J.; Nicewonger, Melinda R.; Kahle, Emma; Souney, Joseph Jr.; Twickler, Mark; Fegyveresi, John; Casey, Kimberly A.; Aydin, Murat", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole Ice Core (SPICEcore) SPC14 Core Quality Versus Depth", "url": "https://www.usap-dc.org/view/dataset/601221"}, {"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": "601396", "doi": "10.15784/601396", "keywords": "Accumulation; Antarctica; Diffusion Length; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Ice Dynamic; Layer Thinning; Oxygen Isotope; South Pole; SPICEcore; Temperature", "people": "Jones, Tyler R.; Kahle, Emma; Steig, Eric J.; White, James; Epifanio, Jenna; Buizert, Christo; Waddington, Edwin D.; Conway, Howard; Stevens, Max; Schauer, Andrew; Vaughn, Bruce; Morris, Valerie; Koutnik, Michelle; Fudge, T. J.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "Temperature, accumulation rate, and layer thinning from the South Pole ice core (SPC14)", "url": "https://www.usap-dc.org/view/dataset/601396"}], "date_created": "Wed, 30 Oct 2019 00:00:00 GMT", "description": "1142517/Saltzman This proposal requests support for a project to drill and recover a new ice core from South Pole, Antarctica. The South Pole ice core will be drilled to a depth of 1500 m, providing an environmental record spanning approximately 40 kyrs. This core will be recovered using a new intermediate drill, which is under development by the U.S. Ice Drilling Design and Operations (IDDO) group in collaboration with Danish scientists. This proposal seeks support to provide: 1) scientific management and oversight for the South Pole ice core project, 2) personnel for ice core drilling and core processing, 3) data management, and 3) scientific coordination and communication via scientific workshops. The intellectual merit of the work is that the analysis of stable isotopes, atmospheric gases, and aerosol-borne chemicals in polar ice has provided unique information about the magnitude and timing of changes in climate and climate forcing through time. The international ice core research community has articulated the goal of developing spatial arrays of ice cores across Antarctica and Greenland, allowing the reconstruction of regional patterns of climate variability in order to provide greater insight into the mechanisms driving climate change. The broader impacts of the project include obtaining the South Pole ice core will support a wide range of ice core science projects, which will contribute to the societal need for a basic understanding of climate and the capability to predict climate and ice sheet stability on long time scales. Second, the project will help train the next generation of ice core scientists by providing the opportunity for hands-on field and core processing experience for graduate students and postdoctoral researchers. A postdoctoral researcher at the University of Washington will be directly supported by this project, and many other young scientists will interact with the project through individual science proposals. Third, the project will result in the development of a new intermediate drill which will become an important resource to US ice core science community. This drill will have a light logistical footprint which will enable a wide range of ice core projects to be carried out that are not currently feasible. Finally, although this project does not request funds for outreach activities, the project will run workshops that will encourage and enable proposals for coordinated outreach activities involving the South Pole ice core science team.", "east": 90.0, "geometry": "POINT(90 -90)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GAS CHROMATOGRAPHS", "is_usap_dc": true, "keywords": "USAP-DC; Amd/Us; Antarctica; ANALYTICAL LAB; USA/NSF; AMD; South Pole; ICE CORE RECORDS; FIELD INVESTIGATION; Ice Core", "locations": "Antarctica; South Pole", "north": -90.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Twickler, Mark; Souney, Joseph Jr.; Aydin, Murat; Steig, Eric J.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e ANALYTICAL LAB", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "SPICEcore", "south": -90.0, "title": "Collaborative Research: A 1500m Ice Core from South Pole", "uid": "p0010060", "west": 90.0}, {"awards": "1443663 Cole-Dai, Jihong; 1443397 Kreutz, Karl; 1443336 Osterberg, Erich", "bounds_geometry": "POINT(-180 -90)", "dataset_titles": "Preliminary SPC14 high-resolution Fe and Mn biologically relevant and dissolved trace metal concentrations spanning -42 \u2013 54,300 years BP.; South Pole Ice Core Holocene Major Ion Dataset; South Pole Ice Core Sea Salt and Major Ions; South Pole ice core (SPC14) discrete methane data; South Pole (SPC14) microparticle concentration, mass concentration, flux, particle-size-distribution mode, and aspect ratio measurements; SPICEcore 400-480 m Major Ions SDSU; The South Pole Ice Core (SPICEcore) chronology and supporting data", "datasets": [{"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": "Winski, Dominic A.; Epifanio, Jenna; Brook, Edward J.; Buizert, Christo; Kreutz, Karl; Aydin, Murat; Edwards, Jon S.; Sowers, Todd A.; Kahle, Emma; Steig, Eric J.; Osterberg, Erich; Fudge, T. J.; Hood, Ekaterina; Kalk, Michael; Ferris, David G.; Kennedy, Joshua A.; 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": "601675", "doi": "10.15784/601675", "keywords": "Antarctica; South Pole; SPICEcore", "people": "Kreutz, Karl", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "Preliminary SPC14 high-resolution Fe and Mn biologically relevant and dissolved trace metal concentrations spanning -42 \u2013 54,300 years BP.", "url": "https://www.usap-dc.org/view/dataset/601675"}, {"dataset_uid": "601553", "doi": "10.15784/601553", "keywords": "Antarctica; Dust; Ice Core; South Pole", "people": "Kreutz, Karl", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole (SPC14) microparticle concentration, mass concentration, flux, particle-size-distribution mode, and aspect ratio measurements", "url": "https://www.usap-dc.org/view/dataset/601553"}, {"dataset_uid": "601430", "doi": "10.15784/601430", "keywords": "Antarctica; Ions; South Pole; SPICEcore", "people": "Cole-Dai, Jihong; Larrick, Carleigh", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "SPICEcore 400-480 m Major Ions SDSU", "url": "https://www.usap-dc.org/view/dataset/601430"}, {"dataset_uid": "601206", "doi": "10.15784/601206", "keywords": "Antarctica; Calcium (ca); Chemistry:ice; Chemistry:Ice; Depth; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciochemistry; Glaciology; Ice; Ice Core; Ice Core Chemistry; Ice Core Data; Ice Core Records; Ice Core Stratigraphy; Nitrate; Nitrogen Isotopes; Paleoclimate; Snow/ice; Snow/Ice; South Pole; SPICEcore", "people": "Buizert, Christo; Severinghaus, Jeffrey P.; Osterberg, Erich; Waddington, Edwin D.; Alley, Richard; Casey, Kimberly A.; Nicewonger, Melinda R.; Aydin, Murat; Ferris, David G.; Kahle, Emma; Morris, Valerie; Steig, Eric J.; Sowers, Todd A.; Beaudette, Ross; Brook, Edward J.; Ortman, Nikolas; Epifanio, Jenna; Kreutz, Karl; Cox, Thomas S.; Thundercloud, Zayta; Cole-Dai, Jihong; Fegyveresi, John; McConnell, Joseph; Sigl, Michael; Souney, Joseph Jr.; Bay, Ryan; Dunbar, Nelia; Fudge, T. J.; Winski, Dominic A.; Iverson, Nels; Jones, Tyler R.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "The South Pole Ice Core (SPICEcore) chronology and supporting data", "url": "https://www.usap-dc.org/view/dataset/601206"}, {"dataset_uid": "601851", "doi": "10.15784/601851", "keywords": "Antarctica; Cryosphere; Glaciology; Ice Core; Ice Core Chemistry; Ice Core Records; Major Ion; Sea Ice; Sea Salt; Sodium; South Pole; SPICEcore", "people": "Winski, Dominic A.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole Ice Core Sea Salt and Major Ions", "url": "https://www.usap-dc.org/view/dataset/601851"}, {"dataset_uid": "601850", "doi": "10.15784/601850", "keywords": "Antarctica; Cryosphere; Glaciology; Ice Core; Ice Core Chemistry; Ice Core Records; Major Ion; Sea Ice; Sea Salt; Sodium; South Pole; SPICEcore", "people": "Winski, Dominic A.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole Ice Core Holocene Major Ion Dataset", "url": "https://www.usap-dc.org/view/dataset/601850"}], "date_created": "Thu, 29 Aug 2019 00:00:00 GMT", "description": "This collaborative project explores the signatures and causes of natural climate change in the region surrounding Antarctica over the last 40,000 years as the Earth transitioned from an ice age into the modern warm period. The researchers will investigate how the wind belts that surround Antarctica changed in their strength and position through time, and document explosive volcanic eruptions and CO2 cycling in the Southern Ocean as potential climate forcing mechanisms over this interval. Understanding how and why the climate varied naturally in the past is critical for improving understanding of modern climate change and projections of future climate under higher levels of atmospheric CO2. The investigators plan to conduct a suite of chemical measurements along the 1500m length of the South Pole Ice Core, including major ion and trace element concentrations, and microparticle (dust) concentrations and size distributions. These measurements will (1) extend the South Pole record of explosive volcanic eruptions to 40,000 years using sulfate and particle data; (2) establish the relative timing of climate changes in dust source regions of Patagonia, New Zealand, and Australia using dust flux data; (3) investigate changes in the strength and position of the westerly wind belt using dust size distribution data; and (4) quantify the flux of bioavailable trace metals deposited as dust to the Southern Ocean over time. These chemistry records will also be critical for creating the timescale that will be used by all researchers studying records from the South Pole core. The project will support four graduate students and several undergraduate students across three different institutions, and become a focus of the investigators\u0027 efforts to disseminate outcomes of climate change science to the broader community.", "east": -180.0, "geometry": "POINT(-180 -90)", "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; ICE CORE RECORDS; USAP-DC; Amd/Us; USA/NSF; LABORATORY; AMD", "locations": "Antarctica", "north": -90.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Osterberg, Erich", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "SPICEcore", "south": -90.0, "title": "Collaborative Research: South Pole Ice Core Chronology and Climate Records using Chemical and Microparticle Measurements", "uid": "p0010051", "west": -180.0}, {"awards": "1401489 Sigman, Daniel", "bounds_geometry": "POLYGON((-180 -45,-144 -45,-108 -45,-72 -45,-36 -45,0 -45,36 -45,72 -45,108 -45,144 -45,180 -45,180 -47.5,180 -50,180 -52.5,180 -55,180 -57.5,180 -60,180 -62.5,180 -65,180 -67.5,180 -70,144 -70,108 -70,72 -70,36 -70,0 -70,-36 -70,-72 -70,-108 -70,-144 -70,-180 -70,-180 -67.5,-180 -65,-180 -62.5,-180 -60,-180 -57.5,-180 -55,-180 -52.5,-180 -50,-180 -47.5,-180 -45))", "dataset_titles": "Deep-sea coral evidence for lower Southern Ocean surface nitrate concentrations during the last ice age; Diatom-bound N isotope records over the last two glacial cycles in sediment core PS75/072-4.; Diatom-bound nitrogen isotope and opal flux records over the Holocene period in Southern Ocean sediment cores MD12-3396, MD11-3353 and PS75/072-4.; GOSHIP section IO8S and P18S", "datasets": [{"dataset_uid": "200048", "doi": "doi.pangaea.de/10.1594/PANGAEA.891436.", "keywords": null, "people": null, "repository": "PANGAEA", "science_program": null, "title": "Diatom-bound nitrogen isotope and opal flux records over the Holocene period in Southern Ocean sediment cores MD12-3396, MD11-3353 and PS75/072-4.", "url": "https://doi.pangaea.de/10.1594/PANGAEA.891436"}, {"dataset_uid": "200050", "doi": "", "keywords": null, "people": null, "repository": "CLIVAR", "science_program": null, "title": "GOSHIP section IO8S and P18S", "url": "https://cchdo.ucsd.edu/"}, {"dataset_uid": "200049", "doi": "doi.org/10.1594/PANGAEA.848271", "keywords": null, "people": null, "repository": "PANGAEA", "science_program": null, "title": "Diatom-bound N isotope records over the last two glacial cycles in sediment core PS75/072-4.", "url": "https://doi.org/10.1594/PANGAEA.848271"}, {"dataset_uid": "200051", "doi": "", "keywords": null, "people": null, "repository": "Publication", "science_program": null, "title": "Deep-sea coral evidence for lower Southern Ocean surface nitrate concentrations during the last ice age", "url": "https://www.pnas.org/content/suppl/2017/03/14/1615718114.DCSupplemental"}], "date_created": "Thu, 08 Aug 2019 00:00:00 GMT", "description": "ABSTRACT Intellectual Merit: The high concentration of the major nutrients nitrate and phosphate is a fundamental characteristic of the Antarctic Zone in the Southern Ocean and is central to its role in global ocean fertility and the global carbon cycle. The isotopic composition of diatom-bound organic nitrogen is one of the best hopes for reconstructing the nutrient status of polar surface waters over glacial cycles, which in turn may hold the explanation for the decline in atmospheric carbon dioxide during ice ages. The PIs propose to generate detailed diatom-bound nitrogen isotope (\u0026#948;15Ndb) records from high sedimentation rate cores from the Kerguelen Plateau. Because the cores were collected at relatively shallow seafloor depths, they have adequate planktonic and benthic foraminifera to develop accurate age models. The resulting data could be compared with climate records from Antarctic ice cores and other archives to investigate climate-related changes, including the major steps into and out of ice ages and the millennial-scale events that occur during ice ages and at their ends. The records generated in this project will provide a critical test of hypotheses for the cause of lower ice age CO2. Broader impacts: This study will contribute to the goal of understanding ice ages and past CO2 changes, which both have broad implications for future climate. Undergraduates will undertake summer internships, with the possibility of extending their work into junior year projects and senior theses. In addition, the PI will lead modules for two Princeton programs for middle school teachers and will host a teacher for a six-week summer research project.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "BIOGEOCHEMICAL CYCLES; South Pacific Ocean; USAP-DC; NOT APPLICABLE", "locations": "South Pacific Ocean", "north": -45.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Sigman, Daniel", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "PANGAEA", "repositories": "CLIVAR; PANGAEA; Publication", "science_programs": null, "south": -70.0, "title": "High-resolution, Assemblage-specific Records of Diatom-bound N Isotopes from the Indian Sector of the Antarctic Ocean", "uid": "p0010046", "west": -180.0}, {"awards": "1644073 DiTullio, Giacomo; 1643684 Saito, Mak", "bounds_geometry": "POLYGON((-180 -72,-173.6 -72,-167.2 -72,-160.8 -72,-154.4 -72,-148 -72,-141.6 -72,-135.2 -72,-128.8 -72,-122.4 -72,-116 -72,-116 -72.7,-116 -73.4,-116 -74.1,-116 -74.8,-116 -75.5,-116 -76.2,-116 -76.9,-116 -77.6,-116 -78.3,-116 -79,-122.4 -79,-128.8 -79,-135.2 -79,-141.6 -79,-148 -79,-154.4 -79,-160.8 -79,-167.2 -79,-173.6 -79,180 -79,178 -79,176 -79,174 -79,172 -79,170 -79,168 -79,166 -79,164 -79,162 -79,160 -79,160 -78.3,160 -77.6,160 -76.9,160 -76.2,160 -75.5,160 -74.8,160 -74.1,160 -73.4,160 -72.7,160 -72,162 -72,164 -72,166 -72,168 -72,170 -72,172 -72,174 -72,176 -72,178 -72,-180 -72))", "dataset_titles": "Algal pigment concentrations from the Ross Sea; Biogenic silica concentrations from the Ross Sea; NBP1801 Expedition data; Nutrients from NBP18-01 CICLOPS", "datasets": [{"dataset_uid": "601205", "doi": "10.15784/601205", "keywords": "Antarctica; Chemistry:fluid; Chemistry:Fluid; Chlorophyll; Chromatography; Liquid Chromatograph; Oceans; Ross Sea; R/v Nathaniel B. Palmer; Sea Water; Seawater Measurements; Southern Ocean; Water Measurements; Water Samples", "people": "Ditullio, Giacomo", "repository": "USAP-DC", "science_program": null, "title": "Algal pigment concentrations from the Ross Sea", "url": "https://www.usap-dc.org/view/dataset/601205"}, {"dataset_uid": "601225", "doi": "10.15784/601225", "keywords": "Antarctica; Biogenic Silica; Biogenic Silica Concentrations; Chemistry:Water; Geochemistry; NBP1801; Oceans; Ross Sea; R/v Nathaniel B. Palmer; Sea Water; Southern Ocean; Spectroscopy; Water Measurements; Water Samples", "people": "Ditullio, Giacomo; Schanke, Nicole", "repository": "USAP-DC", "science_program": null, "title": "Biogenic silica concentrations from the Ross Sea", "url": "https://www.usap-dc.org/view/dataset/601225"}, {"dataset_uid": "200056", "doi": "10.7284/907753", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP1801 Expedition data", "url": "https://www.rvdata.us/search/cruise/NBP1801"}, {"dataset_uid": "601428", "doi": "10.15784/601428", "keywords": "Amundsen Sea; Antarctica; NBP1801; Nitrate; Nitrite; Nutrients; Phosphate; Ross Sea; R/v Nathaniel B. Palmer; Silicic Acid; Terra Nova Bay", "people": "Saito, Mak", "repository": "USAP-DC", "science_program": null, "title": "Nutrients from NBP18-01 CICLOPS", "url": "https://www.usap-dc.org/view/dataset/601428"}], "date_created": "Thu, 08 Aug 2019 00:00:00 GMT", "description": "Phytoplankton blooms in the coastal waters of the Ross Sea, Antarctica are typically dominated by either diatoms or Phaeocystis Antarctica (a flagellated algae that often can form large colonies in a gelatinous matrix). The project seeks to determine if an association of bacterial populations with Phaeocystis antarctica colonies can directly supply Phaeocystis with Vitamin B12, which can be an important co-limiting micronutrient in the Ross Sea. The supply of an essential vitamin coupled with the ability to grow at lower iron concentrations may put Phaeocystis at a competitive advantage over diatoms. Because Phaeocystis cells can fix more carbon than diatoms and Phaeocystis are not grazed as efficiently as diatoms, the project will help in refining understanding of carbon dynamics in the region as well as the basis of the food web webs. Such understanding also has the potential to help refine predictive ecological models for the region. The project will conduct public outreach activities and will contribute to undergraduate and graduate research. Engagement of underrepresented students will occur during summer student internships. A collaboration with Italian Antarctic researchers, who have been studying the Terra Nova Bay ecosystem since the 1980s, aims to enhance the project and promote international scientific collaborations. The study will test whether a mutualistic symbioses between attached bacteria and Phaeocystis provides colonial cells a mechanism for alleviating chronic Vitamin B12 co-limitation effects thereby conferring them with a competitive advantage over diatom communities. The use of drifters in a time series study will provide the opportunity to track in both space and time a developing algal bloom in Terra Nova Bay and to determine community structure and the physiological nutrient status of microbial populations. A combination of flow cytometry, proteomics, metatranscriptomics, radioisotopic and stable isotopic labeling experiments will determine carbon and nutrient uptake rates and the role of bacteria in mitigating potential vitamin B12 and iron limitation. Membrane inlet and proton transfer reaction mass spectrometry will also be used to estimate net community production and release of volatile organic carbon compounds that are climatically active. Understanding how environmental parameters can influence microbial community dynamics in Antarctic coastal waters will advance an understanding of how changes in ocean stratification and chemistry could impact the biogeochemistry and food web dynamics of Southern Ocean ecosystems.", "east": 160.0, "geometry": "POINT(-158 -75.5)", "instruments": null, "is_usap_dc": true, "keywords": "BIOGEOCHEMICAL CYCLES; NBP1801; Amd/Us; USA/NSF; USAP-DC; NUTRIENTS; PIGMENTS; CHLOROPHYLL; R/V NBP; Ross Sea; AMD", "locations": "Ross Sea", "north": -72.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Integrated System Science; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "DiTullio, Giacomo; Lee, Peter", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "USAP-DC", "repositories": "R2R; USAP-DC", "science_programs": null, "south": -79.0, "title": "Collaborative Research: Cobalamin and Iron Co-Limitation Of Phytoplankton Species in Terra Nova Bay", "uid": "p0010045", "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. The 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": "1425989 Sarmiento, Jorge", "bounds_geometry": "POLYGON((-180 -52.6153,-168.67689 -52.6153,-157.35378 -52.6153,-146.03067 -52.6153,-134.70756 -52.6153,-123.38445 -52.6153,-112.06134 -52.6153,-100.73823 -52.6153,-89.41512 -52.6153,-78.09201 -52.6153,-66.7689 -52.6153,-66.7689 -55.18958,-66.7689 -57.76386,-66.7689 -60.33814,-66.7689 -62.91242,-66.7689 -65.4867,-66.7689 -68.06098,-66.7689 -70.63526,-66.7689 -73.20954,-66.7689 -75.78382,-66.7689 -78.3581,-78.09201 -78.3581,-89.41512 -78.3581,-100.73823 -78.3581,-112.06134 -78.3581,-123.38445 -78.3581,-134.70756 -78.3581,-146.03067 -78.3581,-157.35378 -78.3581,-168.67689 -78.3581,180 -78.3581,178.62318 -78.3581,177.24636 -78.3581,175.86954 -78.3581,174.49272 -78.3581,173.1159 -78.3581,171.73908 -78.3581,170.36226 -78.3581,168.98544 -78.3581,167.60862 -78.3581,166.2318 -78.3581,166.2318 -75.78382,166.2318 -73.20954,166.2318 -70.63526,166.2318 -68.06098,166.2318 -65.4867,166.2318 -62.91242,166.2318 -60.33814,166.2318 -57.76386,166.2318 -55.18958,166.2318 -52.6153,167.60862 -52.6153,168.98544 -52.6153,170.36226 -52.6153,171.73908 -52.6153,173.1159 -52.6153,174.49272 -52.6153,175.86954 -52.6153,177.24636 -52.6153,178.62318 -52.6153,-180 -52.6153))", "dataset_titles": "Biogeochemical profiling float data from the Southern Ocean Carbon and Climate Observation and Modeling (SOCCOM) program.UCSD Research Data Collections DOI:10.6075/J09021PC; Expedition Data; Model output NOAA GFDL CM2_6 Cant Hant storage", "datasets": [{"dataset_uid": "601144", "doi": "10.15784/601144", "keywords": "Antarctica; Anthropogenic Heat; Atmosphere; Carbon Storage; Climate Change; Eddy; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Heat Budget; Modeling; Model Output; Oceans; Paleoclimate; Snow/ice; Snow/Ice; Southern Ocean", "people": "Chen, Haidi", "repository": "USAP-DC", "science_program": null, "title": "Model output NOAA GFDL CM2_6 Cant Hant storage", "url": "https://www.usap-dc.org/view/dataset/601144"}, {"dataset_uid": "000208", "doi": "", "keywords": null, "people": null, "repository": "PI website", "science_program": null, "title": "Biogeochemical profiling float data from the Southern Ocean Carbon and Climate Observation and Modeling (SOCCOM) program.UCSD Research Data Collections DOI:10.6075/J09021PC", "url": "http://library.ucsd.edu/dc/object/bb66239018"}, {"dataset_uid": "001369", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP1701"}], "date_created": "Fri, 29 Dec 2017 00:00:00 GMT", "description": "Southern Ocean Carbon and Climate Observations and Modeling (SOCCOM) project seeks to drive a transformative shift in our understanding of the crucial role of the Southern Ocean in taking up anthropogenic carbon and heat, and resupplying nutrients from the abyss to the surface. An observational program will generate vast amounts of new biogeochemical data that will provide a greatly improved view of the dynamics and ecosystem responses of the Southern Ocean. A modeling component will apply these observations to enhancing understanding of the current ocean, reducing uncertainty in projections of future carbon and nutrient cycles and climate. Because it serves as the primary gateway through which the intermediate, deep, and bottom waters of the ocean interact with the surface layers and thus the atmosphere, the Southern Ocean has a profound influence on the oceanic uptake of anthropogenic carbon and heat as well as nutrient resupply from the abyss to the surface. Yet it is the least observed and understood region of the world ocean. The oceanographic community is on the cusp of two major advances that have the potential to transform understanding of the Southern Ocean. The first is the development of new biogeochemical sensors mounted on autonomous profiling floats that allow sampling of ocean biogeochemistry and acidification in 3-dimensional space with a temporal resolution of five to ten days. The SOCCOM float program proposed will increase the average number of biogeochemical profiles measured per month in the Southern Ocean by ~10-30x. The second is that the climate modeling community now has the computational resources and physical understanding to develop fully coupled climate models that can represent crucial mesoscale processes in the Southern Ocean, as well as corresponding models that assimilate observations to produce a state estimate. Together with the observations, this new generation of models provides the tools to vastly improve understanding of Southern Ocean processes and the ability to quantitatively assess uptake of anthropogenic carbon and heat, as well as nutrient resupply, both today and into the future. In order to take advantage of the above technological and modeling breakthroughs, SOCCOM will implement the following research programs: * Theme 1: Observations. Scripps Institution of Oceanography will lead a field program to expand the number of Southern Ocean autonomous profiling floats and equip them with sensors to measure pH, nitrate, and oxygen. The University of Washington and Monterey Bay Aquarium Research Institute will design, build, and oversee deployment of the floats. Scripps will also develop a mesoscale eddying Southern Ocean state estimate that assimilates physical and biogeochemical data into the MIT ocean general circulation model. * Theme 2: Modeling. University of Arizona and Princeton University, together with NOAA\u0027s Geophysical Fluid Dynamics Laboratory (GFDL), will use SOCCOM observations to develop data/model assessment metrics and next-generation model analysis and evaluation, with the goal of improving process level understanding and reducing the uncertainty in projections of our future climate. Led by Climate Central, an independent, non-profit journalism and research organization that promotes understanding of climate science, SOCCOM will collaborate with educators and media professionals to inform policymakers and the public about the challenges of climate change and its impacts on marine life in the context of the Southern Ocean. In addition, the integrated team of SOCCOM scientists and educators will: * communicate data and results of the SOCCOM efforts quickly to the public through established data networks, publications, broadcast media, and a public portal; * train a new generation of diverse ocean scientists, including undergraduate students, graduate students, and postdoctoral fellows versed in field techniques, data calibration, modeling, and communication of research to non-scientists; * transfer new sensor technology and related software to autonomous instrument providers and manufacturers to ensure that they become widely useable.", "east": -66.7689, "geometry": "POINT(-130.26855 -65.4867)", "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": true, "keywords": "USAP-DC; R/V NBP; NBP1701; CLIMATE MODELS", "locations": null, "north": -52.6153, "nsf_funding_programs": "Antarctic Instrumentation and Support; Antarctic Ocean and Atmospheric Sciences; Antarctic Integrated System Science", "paleo_time": null, "persons": "Sarmiento, Jorge; Rynearson, Tatiana", "platforms": "OTHER \u003e MODELS \u003e CLIMATE MODELS; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "USAP-DC", "repositories": "PI website; R2R; USAP-DC", "science_programs": null, "south": -78.3581, "title": "Southern Ocean Carbon and Climate Observations and Modeling (SOCCOM)", "uid": "p0000197", "west": 166.2318}, {"awards": "1246223 Hastings, Meredith", "bounds_geometry": "POINT(-112.1115 -79.481)", "dataset_titles": "WAIS Divide WDC06A Nitrate Isotope Record", "datasets": [{"dataset_uid": "601022", "doi": "10.15784/601022", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Nitrate; WAIS Divide; WAIS Divide Ice Core", "people": "Hastings, Meredith; Buffen, Aron", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide WDC06A Nitrate Isotope Record", "url": "https://www.usap-dc.org/view/dataset/601022"}], "date_created": "Tue, 02 May 2017 00:00:00 GMT", "description": "Hastings/1246223 This award supports a project with the aim of distinguishing the sources of nitrate deposition to the West Antarctic Ice Sheet (WAIS) using isotopic ratios snow in archive snow and ice samples. The isotopic composition of nitrate has been shown to contain information about the source of the nitrate (i.e. nitrogen oxides = NOx = NO+NO2) and the oxidation processes that convert NOx to nitrate in the atmosphere prior to deposition. A difficulty in interpreting records in the context of NOx sources is that nitrate can be post-depositionally processed in surface snow, such that the archived record does not reflect the composition of the atmosphere. This intellectual merit of this work specifically aims to investigate variability in the isotopic composition of nitrate in snow and ice from the WAIS in the context of accumulation rate, NOx source emissions, and atmospheric chemistry. These records will be interpreted in the context of our understanding of biospheric (biomass burning, microbial processes in soils), atmospheric (lightning, transport, chemistry), and climate (temperature, accumulation rate) changes over time. A graduate student will be supported as part of this project, and both graduate student and PI will be involved in communicating the utility and results of polar research to elementary school students in the Providence, RI area. The broader impacts of the project also include making efforts to attract more young, female scientists to polar research by establishing a connection between the Earth Science Women\u0027s Network (ESWN), an organization PI Hastings helped to establish, and the Association of Polar Early Career Scientists (APECS). Finally, results of all measurements will be presented at relevant conferences, made available publicly and published in peer-reviewed journals.", "east": -112.1115, "geometry": "POINT(-112.1115 -79.481)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -79.481, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Hastings, Meredith", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.481, "title": "Investigating Source, Chemistry and Climate changes using the Isotopic Composition of Nitrate in Antarctic Snow and Ice", "uid": "p0000399", "west": -112.1115}, {"awards": "0538520 Thiemens, Mark; 0538049 Steig, Eric", "bounds_geometry": "POINT(-112.085 -79.5)", "dataset_titles": "Multiple Isotope Analysis of Sulfate in the West Antarctic Ice Sheet Divide Ice Core; WAIS Divide sulfate and nitrate isotopes; WAIS ice core isotope data #387, 385 (full data link not provided)", "datasets": [{"dataset_uid": "002512", "doi": "", "keywords": null, "people": null, "repository": "Project website", "science_program": null, "title": "WAIS ice core isotope data #387, 385 (full data link not provided)", "url": "http://www.waisdivide.unh.edu/"}, {"dataset_uid": "609479", "doi": "10.7265/N5BG2KXH", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Paleoclimate; WAIS Divide; WAIS Divide Ice Core", "people": "Thiemens, Mark H.", "repository": "USAP-DC", "science_program": null, "title": "Multiple Isotope Analysis of Sulfate in the West Antarctic Ice Sheet Divide Ice Core", "url": "https://www.usap-dc.org/view/dataset/609479"}, {"dataset_uid": "601007", "doi": "10.15784/601007", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Nitrate; Oxygen Isotope; Sulfate; WAIS Divide; WAIS Divide Ice Core", "people": "Alexander, Becky; Steig, Eric J.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide sulfate and nitrate isotopes", "url": "https://www.usap-dc.org/view/dataset/601007"}], "date_created": "Tue, 25 Apr 2017 00:00:00 GMT", "description": "0538520\u003cbr/\u003eThiemens\u003cbr/\u003eThis award supports a project to develop the first complete record of multiple isotope ratios of nitrate and sulfate covering the last ~100,000 years, from the deep ice core planned for the central ice divide of the West Antarctic Ice Sheet (WAIS). The WAIS Divide ice core will be the highest resolution long ice core obtained from Antarctica and we can expect important complementary information to be available, including accurate knowledge of past accumulation rates, temperatures, and compounds such as H2O2, CO and CH4. These compounds play significant roles in global atmospheric chemistry and climate. Especially great potential lies in the use of multiple isotope signatures. The unique mass independent fractionation (MIF) 17O signature of ozone is observed in both nitrate and sulfate, due to the interaction of their precursors with ozone. The development of methods to measure the multiple-isotope composition of small samples of sulfate and nitrate makes continuous high resolution measurements on ice cores feasible for the first time. Recent work has shown that such measurements can be used to determine the hydroxyl radial (OH) and ozone (O3) concentrations in the paleoatmosphere as well as to apportion sulfate and nitrate sources. There is also considerable potential in using these isotope measurements to quantify post depositional changes. In the first two years, continuous measurements from the upper ~100-m of ice at WAIS divide will be obtained, to provide a detailed look at seasonal through centennial scale variability. In the third year, measurements will be made throughout the available depth of the deep core (expected to reach ~500 m at this time). The broader impacts of the project include applications to diverse fields including atmospheric chemistry, glaciology, meteorology, and paleoclimatology. Because nitrate and sulfate are important atmospheric pollutants, the results will also have direct and relevance to global environmental policy. This project will coincide with the International Polar Year (2007-2008), and contributes to goals of the IPY, which include the fostering of interdisciplinary research toward enhanced understanding of atmospheric chemistry and climate in the polar regions.", "east": -112.085, "geometry": "POINT(-112.085 -79.5)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS", "is_usap_dc": true, "keywords": "Isotope Ratios; Temperature; Sulfate; West Antarctic; Paleoatmosphere; LABORATORY; Ice Core; Ice Core Data; Mass Independent Fractionation; FIELD SURVEYS; Not provided; Accumulation Rate; Oxygen Isotope; FIELD INVESTIGATION; Ice Core Chemistry; Isotope", "locations": "West Antarctic", "north": -79.5, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Alexander, Becky; Steig, Eric J.; Thiemens, Mark H.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "Project website", "repositories": "Project website; USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.5, "title": "Collaborative Research: Multiple-isotope Analysis of Nitrate and Sulfate in the West Antarctic Ice Sheet Divide Ice Core", "uid": "p0000020", "west": -112.085}, {"awards": "0636929 Bales, Roger", "bounds_geometry": null, "dataset_titles": "Measurements of Air and Snow Photochemical Species at WAIS Divide, Antarctica", "datasets": [{"dataset_uid": "609585", "doi": "10.7265/N5GX48HW", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; WAIS Divide; WAIS Divide Ice Core", "people": "Bales, Roger", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Measurements of Air and Snow Photochemical Species at WAIS Divide, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609585"}], "date_created": "Thu, 14 Jul 2011 00:00:00 GMT", "description": "This award supports a project to understand how recent changes in atmospheric chemistry, and historical changes as recorded in snow, firn and ice, have affected atmospheric photochemistry over Antarctica. Atmospheric, snow and firn core measurements of selected gas, meteorological and snow physical properties will be made and modeling of snow-atmosphere exchange will be carried out. The intellectual merit of the project is that it will lead to a better an understanding of the atmospheric chemistry in West Antarctica, its bi-directional linkages with the snowpack, and how it responds to regional influences. There are at least four broader impacts of this work. First is education of university students at both the graduate and undergraduate levels. One postdoctoral researcher and one graduate student will carry out much of the work, and a number of undergraduates will be involved. Second, involvement with the WAIS-Divide coring program will be used to help recruit under-represented groups as UC Merced students. As part of UC Merced\u0027s outreach efforts in the San Joaquin Valley, whose students are under-represented in the UC system, the PI and co-PI give short research talks to groups of prospective students, community college and high school educators and other groups. They will develop one such talk highlighting this project. Including high-profile research in these recruiting talks has proven to be an effective way to promote dialog, and interest students in UC Merced. Third, talks such as this also contribute to the scientific literacy of the general public. The PI and grad student will all seek opportunities to share project information with K-14 and community audiences. Fourth, results of the research will be disseminated broadly to the scientific community, and the researchers will seek additional applications for the transfer functions as tools to improve interpretation of ice-cores. This research is highly collaborative, and leverages the expertise and data from a number of other groups.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e CHEMILUMINESCENCE", "is_usap_dc": true, "keywords": "Snow; Atmospheric Chemistry; Not provided; LABORATORY; Antarctica; FIELD SURVEYS; Snow Physical Properties; Meteorology; Wais Divide-project; Firn; Atmosphere Exchange; WAIS Divide; FIELD INVESTIGATION", "locations": "Antarctica; WAIS Divide", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Bales, Roger", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": null, "title": "Atmospheric, Snow and Firn Chemistry Studies for Interpretation of WAIS-Divide Cores", "uid": "p0000041", "west": null}, {"awards": "0087401 Smith, Walker", "bounds_geometry": null, "dataset_titles": "Current Meter Data from the Ross Sea acquired with a Mooring deployed in December 2005 and recovered during the Nathaniel B. Palmer expedition NBP0601A (2006); Expedition data of NBP0301B; Expedition data of NBP0305A; Expedition data of NBP0501; Expedition data of NBP0601A; Fluorometer Data acquired on Moorings deployed the Ross Sea and recovered during the Nathaniel B. Palmer expedition NBP0601A (2006); Processed Fluid Chemistry Data from the Ross Sea acquired during the Nathaniel B. Palmer expedition NBP0601A", "datasets": [{"dataset_uid": "002623", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0601A", "url": "https://www.rvdata.us/search/cruise/NBP0601A"}, {"dataset_uid": "601333", "doi": null, "keywords": "Antarctica; Flourometer; Mooring; NBP0601A; Ross Sea; Southern Ocean", "people": "Smith, Walker; Asper, Vernon", "repository": "USAP-DC", "science_program": null, "title": "Fluorometer Data acquired on Moorings deployed the Ross Sea and recovered during the Nathaniel B. Palmer expedition NBP0601A (2006)", "url": "https://www.usap-dc.org/view/dataset/601333"}, {"dataset_uid": "601339", "doi": null, "keywords": "Antarctica; Current Meter; Mooring; NBP0601A; Oceans; Physical Oceanography; Ross Sea; Southern Ocean", "people": "Smith, Walker; Asper, Vernon", "repository": "USAP-DC", "science_program": null, "title": "Current Meter Data from the Ross Sea acquired with a Mooring deployed in December 2005 and recovered during the Nathaniel B. Palmer expedition NBP0601A (2006)", "url": "https://www.usap-dc.org/view/dataset/601339"}, {"dataset_uid": "002627", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0501", "url": "https://www.rvdata.us/search/cruise/NBP0501"}, {"dataset_uid": "601341", "doi": null, "keywords": "Antarctica; Chemistry:fluid; Chemistry:Fluid; Fluid Chemistry Data; Mooring; NBP0601A; Oceans; Ross Sea; R/v Nathaniel B. Palmer; Seawater Measurements; Southern Ocean", "people": "Smith, Walker; Asper, Vernon", "repository": "USAP-DC", "science_program": null, "title": "Processed Fluid Chemistry Data from the Ross Sea acquired during the Nathaniel B. Palmer expedition NBP0601A", "url": "https://www.usap-dc.org/view/dataset/601341"}, {"dataset_uid": "002622", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0501", "url": "https://www.rvdata.us/search/cruise/NBP0501"}, {"dataset_uid": "002583", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0301B", "url": "https://www.rvdata.us/search/cruise/NBP0301B"}, {"dataset_uid": "002621", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0305A", "url": "https://www.rvdata.us/search/cruise/NBP0305A"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "During the past few decades of oceanographic research, it has been recognized that significant variations in biogeochemical processes occur among years. Interannual variations in the Southern Ocean are known to occur in ice extent and concentration, in the composition of herbivore communities, and in bird and marine mammal distributions and reproductive success. However, little is known about the interannual variations in production of phytoplankton or the role that these variations play in the food web. This project will collect time series data on the seasonal production of phytoplankton in the southern Ross Sea, Antarctica. Furthermore, it will assess the interannual variations of the production of the two major functional groups of the system, diatoms and Phaeocystis Antarctica, a colonial haptophyte. The Ross Sea provides a unique setting for this type of investigation for a number of reasons. For example, a de facto time-series has already been initiated in the Ross Sea through the concentration of a number of programs in the past ten years. It also is well known that the species diversity is reduced relative to other systems and its seasonal production is as great as anywhere in the Antarctic. Most importantly, seasonal production of both the total phytoplankton community (as well as its two functional groups) can be estimated from late summer nutrient profiles. The project will involve short cruises on the US Coast Guard ice breakers in the southern Ross Sea that will allow the collection of water column nutrient and particulate after data at specific locations in the late summer of each of five years. Additionally, two moorings with in situ nitrate analyzers moored at fifteen will be deployed, thus collecting for the first time in the in the Antarctic a time-series of euphotic zone nutrient concentrations over the entire growing season. All nutrient data will be used to calculate seasonal production for each year in the southern Ross Sea and compared to previously collected information, thereby providing an assessment of interannual variations in net community production. Particulate matter data will allow us to estimate the amount of export from the surface layer by late summer, and therefore calculate the interannual variability of this ecosystem process. Interannual variations of seasonal production (and of the major taxa of producers) are a potentially significant feature in the growth and survival of higher trophic levels within the food web of the Ross Sea. They are also important in order to understand the natural variability in biogeochemical processes of the region. Because polar regions such as the Ross Sea are predicted to be impacted by future climate change, biological changes are also anticipated. Placing these changes in the context of natural variability is an essential element of understanding and predicting such alterations. This research thus seeks to quantify the natural variability of an Antarctic coastal system, and ultimately understand its causes and impacts on food webs and biogeochemical cycles of 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; 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; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS", "is_usap_dc": false, "keywords": "Ross Sea; AMD; USAP-DC; Amd/Us; USA/NSF; R/V NBP", "locations": "Ross Sea", "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Smith, Walker; Gordon, Arnold", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R; USAP-DC", "science_programs": null, "south": null, "title": "Interannual Variability in the Antarctic-Ross Sea (IVARS): Nutrients and Seasonal Production", "uid": "p0000803", "west": null}, {"awards": "9317587 Smith, Walker", "bounds_geometry": null, "dataset_titles": "Expedition Data; Expedition data of NBP9406", "datasets": [{"dataset_uid": "002252", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP9406"}, {"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"}], "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": "0739583 Bowser, Samuel; 0739512 Walker, Sally; 0739496 Miller, Molly", "bounds_geometry": "POLYGON((163.41667 -77.33333,163.46667 -77.33333,163.51667 -77.33333,163.56667 -77.33333,163.61667 -77.33333,163.66667 -77.33333,163.71667 -77.33333,163.76667 -77.33333,163.81667 -77.33333,163.86667 -77.33333,163.91667 -77.33333,163.91667 -77.369997,163.91667 -77.406664,163.91667 -77.443331,163.91667 -77.479998,163.91667 -77.516665,163.91667 -77.553332,163.91667 -77.589999,163.91667 -77.626666,163.91667 -77.663333,163.91667 -77.7,163.86667 -77.7,163.81667 -77.7,163.76667 -77.7,163.71667 -77.7,163.66667 -77.7,163.61667 -77.7,163.56667 -77.7,163.51667 -77.7,163.46667 -77.7,163.41667 -77.7,163.41667 -77.663333,163.41667 -77.626666,163.41667 -77.589999,163.41667 -77.553332,163.41667 -77.516665,163.41667 -77.479998,163.41667 -77.443331,163.41667 -77.406664,163.41667 -77.369997,163.41667 -77.33333))", "dataset_titles": "Linking Modern Benthic Communities and Taphonomic Processes to the Stratigraphic Record of Antarctic Cores; Nitrogen, carbon, and oxygen isotopes in the shell of the Antarctic scallop Adamussium colbecki as a proxy for sea ice cover in Antarctica.; Sequence Data", "datasets": [{"dataset_uid": "600076", "doi": "10.15784/600076", "keywords": "Biota; Geochronology; Marine Sediments; Oceans; Southern Ocean", "people": "Miller, Molly; Furbish, David", "repository": "USAP-DC", "science_program": null, "title": "Linking Modern Benthic Communities and Taphonomic Processes to the Stratigraphic Record of Antarctic Cores", "url": "https://www.usap-dc.org/view/dataset/600076"}, {"dataset_uid": "600077", "doi": "10.15784/600077", "keywords": "Antarctica; Biota; Glaciers/ice Sheet; Glaciers/Ice Sheet; McMurdo Sound; Oceans; Sample/collection Description; Sample/Collection Description", "people": "Walker, Sally", "repository": "USAP-DC", "science_program": null, "title": "Linking Modern Benthic Communities and Taphonomic Processes to the Stratigraphic Record of Antarctic Cores", "url": "https://www.usap-dc.org/view/dataset/600077"}, {"dataset_uid": "601764", "doi": "10.15784/601764", "keywords": "Adamussium Colbecki; Antarctica; Biota; Carbon Isotopes; Explorers Cove; Nitrogen Isotopes; Oxygen Isotope; Scallop", "people": "Gillikin, David; Puhalski, Emma; Camarra, Steve; Cronin, Kelly; Verheyden, Anouk; Walker, Sally", "repository": "USAP-DC", "science_program": null, "title": "Nitrogen, carbon, and oxygen isotopes in the shell of the Antarctic scallop Adamussium colbecki as a proxy for sea ice cover in Antarctica.", "url": "https://www.usap-dc.org/view/dataset/601764"}, {"dataset_uid": "000144", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Sequence Data", "url": "http://www.ncbi.nlm.nih.gov/sites/myncbi/collections/public/1rMU2lBNcxWAsa9h9WyD8rzA8/"}], "date_created": "Wed, 15 Jul 2009 00:00:00 GMT", "description": "This project answers a simple question: why are there so few fossils in sediment cores from Antarctica?s continental shelf? Antarctica?s benthos are as biologically rich as those of the tropics. Shell-secreting organisms should have left a trail throughout geologic time, but have not. This trail is particularly important because these organisms record regional climate in ways that are critical to interpreting the global climate record. This study uses field experiments and targeted observations of modern benthic systems to examine the biases inflicted by fossil preservation. By examining a spectrum of ice-affected habitats, this project provides paleoenvironmental insights into carbonate preservation, sedimentation rates, and burial processes; and will provide new approaches to reconstructing the Cenozoic history of Antarctica. Broader impacts include graduate and undergraduate research and education, development of undergraduate curricula to link art and science, K12 outreach, public outreach via the web, and societal relevance through improved understanding of records of global climate change.", "east": 163.91667, "geometry": "POINT(163.66667 -77.516665)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -77.33333, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Walker, Sally; Bowser, Samuel; Miller, Molly; Furbish, David", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "NCBI GenBank; USAP-DC", "science_programs": null, "south": -77.7, "title": "Collaborative Research: Linking Modern Benthic Communities and Taphonomic Processes to the Stratigraphic Record of Antarctic Cores", "uid": "p0000203", "west": 163.41667}, {"awards": "0230288 Anastasio, Cort", "bounds_geometry": "POLYGON((123.30014 -75.093445,123.307404 -75.093445,123.314668 -75.093445,123.321932 -75.093445,123.329196 -75.093445,123.33646 -75.093445,123.343724 -75.093445,123.350988 -75.093445,123.358252 -75.093445,123.365516 -75.093445,123.37278 -75.093445,123.37278 -75.0952669,123.37278 -75.0970888,123.37278 -75.0989107,123.37278 -75.1007326,123.37278 -75.1025545,123.37278 -75.1043764,123.37278 -75.1061983,123.37278 -75.1080202,123.37278 -75.1098421,123.37278 -75.111664,123.365516 -75.111664,123.358252 -75.111664,123.350988 -75.111664,123.343724 -75.111664,123.33646 -75.111664,123.329196 -75.111664,123.321932 -75.111664,123.314668 -75.111664,123.307404 -75.111664,123.30014 -75.111664,123.30014 -75.1098421,123.30014 -75.1080202,123.30014 -75.1061983,123.30014 -75.1043764,123.30014 -75.1025545,123.30014 -75.1007326,123.30014 -75.0989107,123.30014 -75.0970888,123.30014 -75.0952669,123.30014 -75.093445))", "dataset_titles": "Light Absorption Coefficients for Soluble Species in Snow, Dome C, Antarctica", "datasets": [{"dataset_uid": "609519", "doi": "10.7265/N5MS3QP0", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Dome C Ice Core; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Physical Properties; Snow/ice; Snow/Ice", "people": "Robles, Tony; Anastasio, Cort", "repository": "USAP-DC", "science_program": "Dome C Ice Core", "title": "Light Absorption Coefficients for Soluble Species in Snow, Dome C, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609519"}], "date_created": "Wed, 07 Mar 2007 00:00:00 GMT", "description": "Photochemical reactions in snow can have important effects on the chemistry and composition of the snowpack as well as the overlying atmosphere. For example, recent measurements in the Antarctic and Arctic have revealed that sunlit snow releases a number of important pollutants to the atmosphere. Our ability to understand and model this chemistry is currently limited, in part because we lack fundamental photochemical information for a number of important chemical species in snow. This award supports research that will help fill this gap by characterizing the low-temperature photochemistry of three of these key species: nitrite (NO2-), nitrous acid (HNO2), and hydrogen peroxide (HOOH). We will measure quantum yields for these reactions on ice using a sensitive technique that we recently developed during a study of nitrate (NO3-) photochemistry. In addition to this basic research, we will also measure the rates of formation of hydroxyl radical (OH), nitrogen oxides (NOx), and HOOH in illuminated Antarctic snow samples. These measurements will be important inputs for future models, and will allow us to test whether known species (e.g., NO3-, NO2- and HNO2) are responsible for most of snowpack reactivity (e.g., OH formation). Overall, results from this award will significantly improve our ability to understand snowpack chemistry, and the resulting effects on the atmosphere, both in the Antarctic as well as in the many other regions with permanent or seasonal snow. These results will also strengthen efforts to use ice core records to monitor global change. In addition to these impacts, this award will help train students and a postdoctoral fellow, and results from this work will be integrated into two classes in order to expose students to some of the important issues facing polar regions.", "east": 123.37278, "geometry": "POINT(123.33646 -75.1025545)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PHOTON/OPTICAL DETECTORS \u003e PHOTOMETERS \u003e SPECTROPHOTOMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e HPLC; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e ION CHROMATOGRAPHS", "is_usap_dc": true, "keywords": "Snow Chemistry; Antarctica; Snowpack Chemistry; Snow Samples; Hydrogen Peroxide; Snow Properties; Pollutants; Chemistry; Light Absorption; Antarctic; Chemical Species; Snow; East Antarctica; Organic Compounds; Photochemistry; LABORATORY", "locations": "Antarctica; East Antarctica; Antarctic", "north": -75.093445, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Anastasio, Cort; Robles, Tony", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Dome C Ice Core", "south": -75.111664, "title": "Laboratory Studies of Photochemistry in Antarctic Snow and Ice", "uid": "p0000175", "west": 123.30014}, {"awards": "0338363 Thiemens, Mark; 0337933 Cole-Dai, Jihong", "bounds_geometry": null, "dataset_titles": "Major Ion Concentrations in 2004 South Pole Ice Core", "datasets": [{"dataset_uid": "609542", "doi": "10.7265/N5HX19N8", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Ion Chromatograph; South Pole", "people": "Cole-Dai, Jihong", "repository": "USAP-DC", "science_program": null, "title": "Major Ion Concentrations in 2004 South Pole Ice Core", "url": "https://www.usap-dc.org/view/dataset/609542"}], "date_created": "Fri, 11 Aug 2006 00:00:00 GMT", "description": "This award supports a collaborative study between South Dakota State University (SDSU) and University of California, San Diego (UCSD) to investigate the oxygen and sulfur isotope composition of sulfates from a number of large volcanic eruptions in the past 1000 years. The project aims to drill a number of shallow ice cores at South Pole and return them to SDSU and UCSD lab for chemical and isotope analysis. Preliminary results from measurements of isotopes in sulfate samples from several volcanic eruptions in Antarctic snow and ice indicate that isotopic composition of volcanic sulfate contains abundant valuable information on atmospheric chemical and dynamic processes that have not been previously investigated. One tentative conclusion is that mass-independently fractionated sulfur isotopes reveal that atmospheric photolysis of sulfur compounds occurs at longer UV wavelengths than those in the Archean atmosphere, possibly reflecting the atmospheric ozone and/or oxygen concentration. This suggests that isotopic composition of atmospheric sulfate may be used to understand the role of UV radiation in sulfur dioxide conversion in the atmosphere and to track the evolution (i.e., oxygenation) of the atmosphere and the origin of life on Earth. Other major research objectives include understanding what impact massive volcanic eruptions have on the oxidative capacity of the atmosphere, what oxidants and mechanisms are involved in the oxidation or conversion of volcanic sulfur dioxide to sulfate in the stratosphere and what isotopic criteria may be used to differentiate ice core signals of stratospheric eruptions from those of tropospheric eruptions. By providing educational and research opportunities to graduate and undergraduate students at both SDSU and UCSD, the proposed project will promote the integration of research and education and contribute to human resource development in science and engineering. The project will contribute to a proposed REU chemistry site program at SDSU. This collaboration will utilize the complementary strengths of both labs and promote exchange between the two institutions. International collaboration will enhance scientific cooperation between France and US.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e ION CHROMATOGRAPHS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS", "is_usap_dc": true, "keywords": "Not provided; Ion Chromatograph; Ions; LABORATORY; GROUND-BASED OBSERVATIONS", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Cole-Dai, Jihong", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Investigating Atmospheric Chemistry and Dynamics through Oxygen and Sulfur Isotopes in Volcanic Sulfate from South Pole Ice Cores", "uid": "p0000031", "west": null}, {"awards": "0125761 Thiemens, Mark", "bounds_geometry": null, "dataset_titles": "Atmospheric Nitrate Isotopic Analysis at Amundsen-Scott South Pole Station, A Twenty-Five Year Record", "datasets": [{"dataset_uid": "609281", "doi": "10.7265/N5TT4NWF", "keywords": "Aerosol; Antarctica; Atmosphere; Chemistry:fluid; Chemistry:Fluid; Geochemistry; NBP1502; Snow/ice; Snow/Ice; South Pole Station", "people": "Savarino, Joel; Thiemens, Mark H.", "repository": "USAP-DC", "science_program": null, "title": "Atmospheric Nitrate Isotopic Analysis at Amundsen-Scott South Pole Station, A Twenty-Five Year Record", "url": "https://www.usap-dc.org/view/dataset/609281"}], "date_created": "Tue, 27 Dec 2005 00:00:00 GMT", "description": "This award supports a detailed laboratory analysis of the mass-independent isotopic composition of processes associated with atmospheric nitrate trapped in the snow pack at the South Pole. The project will specifically test if the oxygen isotopes 16O, 17O, 18O of nitrate can be used to probe the denitrification of the Antarctic stratosphere. Despite decades of research, there are several important issues in Antarctic atmospheric science, which are presently inadequately resolved. This includes quantification over time of the sources of nitrate aerosols. Today, little is known about the past denitrification of the stratosphere in high latitude regions. This lack of knowledge significantly limits our ability to understand the chemical state of ancient atmospheres and therefore evaluate present and past-coupled climate/atmosphere models. The role of nitrogen in environmental degradation is well known. This issue will also be addressed in this proposal. Atmospheric aerosols have now been shown to possess a mass-independent oxygen isotopic content. The proposed research will investigate the stable oxygen isotope ratios of nitrate in Antarctica both collected in real time and from the snow. Two periods of time will be covered. Full year nitrate aerosol collections, with week resolution time horizons, will be performed at the South Pole. Weekly aerosol collections will help us to identify any seasonal trend of the oxygen-17 excess anomaly, and eventually link this anomaly to the denitrification of the Antarctic stratosphere. This data set will also be used to test our assumption that the oxygen isotopic anomaly of nitrate is mainly formed in the stratosphere and is well preserved in the snow pack. If true, we will for the first time resolve an atmospheric signal extracted from a nitrate profile. The snow pit will allow us to see any trend in the data on a multiple decade timescale.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS", "is_usap_dc": true, "keywords": "Snow; GROUND STATIONS; Ion Chemistry; South Pole; Not provided; Aerosol; Oxygen Isotope; GROUND-BASED OBSERVATIONS; Snow Pit; Antarctica; Admundsen-Scott Station", "locations": "Antarctica; South Pole", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Savarino, Joel; Thiemens, Mark H.", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS; Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "South Pole Atmospheric Nitrate Isotopic Analysis (SPANIA)", "uid": "p0000242", "west": null}, {"awards": "9316564 Mayewski, Paul", "bounds_geometry": null, "dataset_titles": "Ross Ice Drainage System (RIDS) Glaciochemical Analysis; Siple Dome Ice Core Chemistry and Ion Data", "datasets": [{"dataset_uid": "609266", "doi": "10.7265/N5M906KG", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Paleoclimate; Snow/ice; Snow/Ice; Snow Pit", "people": "Kreutz, Karl; Meeker, Loren D.; Twickler, Mark; Mayewski, Paul A.; Whitlow, Sallie", "repository": "USAP-DC", "science_program": null, "title": "Ross Ice Drainage System (RIDS) Glaciochemical Analysis", "url": "https://www.usap-dc.org/view/dataset/609266"}, {"dataset_uid": "609251", "doi": "", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Paleoclimate; Siple Dome; Siple Dome Ice Core", "people": "Dunbar, Nelia; Brook, Edward J.; Mayewski, Paul A.; Blunier, Thomas; Severinghaus, Jeffrey P.; Kreutz, Karl", "repository": "NCEI", "science_program": "Siple Dome Ice Core", "title": "Siple Dome Ice Core Chemistry and Ion Data", "url": "https://www.ncei.noaa.gov/access/paleo-search/study/2461"}], "date_created": "Thu, 26 Aug 2004 00:00:00 GMT", "description": "9316564 Mayewski This award is for support for a three year program to provide a high resolution record of the Antarctic climate through the acquisition, analysis, and interpretation of records of atmospheric chemical deposition taken from three ice cores located at sites within or immediately adjacent to the Ross Ice Drainage System (RIDS). These cores include one from Taylor Dome, and two from West Antarctic locations identified as potential deep drilling sites for the WAISCORES program. Collection of the two West Antarctic cores is intended to be a lightweight dry-drilling operation to depths of ~ 200 m, which will provide records of \u003e 2 kyr. Glaciochemical analyses will focus on the major cations and anions found in the antarctic atmosphere, plus methanesulfonic acid and selected measurements of the hydrogen ion, aluminum, iron, and silica. These analyses, and companion stable isotope and particle measurements to be carried out by other investigators require \u003c 7% by volume of each core, leaving \u003e 90% for other investigators and storage at the U.S. National Ice Core Laboratory. These records are intended to solve a variety of scientific objectives while also providing spatial sampling and reconnaissance for future U.S. efforts in West Antarctica. ***", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e ION CHROMATOGRAPHS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": true, "keywords": "Magnesium; GROUND STATIONS; Nitrate; Methane Sulfonic Acid; Sodium; Ice Core Chemistry; Ammonium (NH4); Sulfate; Ice Core; Chloride; Potassium (k); Calcium (ca)", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE", "persons": "Kreutz, Karl; Twickler, Mark; Whitlow, Sallie; Blunier, Thomas; Dunbar, Nelia; Brook, Edward J.; Mayewski, Paul A.; Meeker, Loren D.; Severinghaus, Jeffrey P.", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS", "repo": "USAP-DC", "repositories": "NCEI; USAP-DC", "science_programs": "Siple Dome Ice Core", "south": null, "title": "Ross Ice Drainage System (RIDS) Late Holocene Climate Variability", "uid": "p0000145", "west": null}, {"awards": "0126286 McConnell, Joseph", "bounds_geometry": "POLYGON((-180 -62.83,-144 -62.83,-108 -62.83,-72 -62.83,-36 -62.83,0 -62.83,36 -62.83,72 -62.83,108 -62.83,144 -62.83,180 -62.83,180 -65.547,180 -68.264,180 -70.981,180 -73.698,180 -76.415,180 -79.132,180 -81.849,180 -84.566,180 -87.283,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87.283,-180 -84.566,-180 -81.849,-180 -79.132,-180 -76.415,-180 -73.698,-180 -70.981,-180 -68.264,-180 -65.547,-180 -62.83))", "dataset_titles": "Siple Shallow Core Density Data", "datasets": [{"dataset_uid": "609129", "doi": "10.7265/N52F7KCD", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Physical Properties; Siple Dome; Siple Dome Ice Core; WAISCORES", "people": "Lamorey, Gregg W.", "repository": "USAP-DC", "science_program": null, "title": "Siple Shallow Core Density Data", "url": "https://www.usap-dc.org/view/dataset/609129"}], "date_created": "Mon, 19 Apr 2004 00:00:00 GMT", "description": "This award provides one year of support to use newly developed technology in which an ice-core melter is coupled with both an Inductively Coupled Plasma - Mass Spectrometer (ICP-MS) and a traditional Continuous Flow Analysis (CFA) system, to measure a continuous time series of chemical and trace element deposition on the Siple Dome ice core from West Antarctica. A coupled ice-core melter, ICP-MS, and CFA system will be used to measure concentrations of a number of elements, isotopes and chemical species at very high depth resolution (~2-cm) in the top 54 m of the Siple Dome A-core. Pilot data from analyses of ~6 m from the nearby but much lower accumulation J-core site at Siple Dome, together with more extensive results from Summit, Greenland, indicate that it will be possible to obtain exactly co-registered, high-quality records of at least 12 seasonally varying elements (sodium, magnesium, aluminum, potassium, calcium, iron, manganese, rubidium, strontium, zirconium, barium, lead) and three other chemical species and ions (ammonium, nitrate, calcium ion) with this system. Under this proposed research, we will also add continuous measurements of sulfate to our system. Because more than sufficient core from Siple Dome for these depths is archived at the National Ice Core Laboratory, the proposed research will require no fieldwork. The continuous, very high-resolution, ~350-y record of these elemental tracers will enhance the value of previous chemical and isotopic measurements that have been made on the Siple Dome core and will be particularly valuable for comparisons between ice-core proxies and modern instrumental data related to El Nino-Southern Oscillation (ENSO) as well as for validation of model simulations of atmospheric circulation. These data, and the expertise gained through this research, will be invaluable when this novel chemical analysis technology is eventually applied to deep ice-core records for the study of rapid climate-change events.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": true, "keywords": "WAISCORES; Siple Coast; Glaciology; Not provided; GROUND-BASED OBSERVATIONS; Ice Core; Siple; Antarctica; Density; Snow; Ice Sheet; Siple Dome; Shallow Core; GROUND STATIONS; Stratigraphy", "locations": "Antarctica; Siple; Siple Coast; Siple Dome", "north": -62.83, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Lamorey, Gregg W.; McConnell, Joseph", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS; Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": -90.0, "title": "Continuous High Resolution Ice-Core Chemistry using ICP-MS at Siple Dome", "uid": "p0000159", "west": -180.0}, {"awards": "9526449 Mayewski, Paul", "bounds_geometry": null, "dataset_titles": "WAISCORES Snow Pit Chemistry, Antarctica", "datasets": [{"dataset_uid": "609420", "doi": "10.7265/N5SQ8XBR", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Paleoclimate; Snow/ice; Snow/Ice; Snow Pit; WAIS; WAISCORES", "people": "Mayewski, Paul A.; Kreutz, Karl", "repository": "USAP-DC", "science_program": null, "title": "WAISCORES Snow Pit Chemistry, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609420"}], "date_created": "Thu, 11 Jul 2002 00:00:00 GMT", "description": "This award is for support for a program of glaciochemical analyses of shallow and deep ice cores from Siple Dome, West Antarctica. Measurements that have been proposed include chloride, nitrate, sulfate, calcium, magnesium, sodium, potassium, ammonium and methansulfonic acid. These measurements will provide information about past volcanic events, biomass source strength, sea ice fluctuations, atmospheric circulation, changes in ice-free areas and the environmental response to Earth orbit insolation changes and solar variability. The glaciochemical records from the Siple Dome core will be developed at a resolution sufficient to compare with the Summit, Greenland record, thus allowing a bipolar comparison of climate change event timing and magnitude. As part of this award, an international workshop will be held during the first year to formulate a science plan for the International Transantarctic Scientific Expedition (ITASE), a program of regional surveys documenting the spatial distribution of properties measured in ice cores .", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Ion Chemistry; Antarctic; Snow Chemistry; Stable Isotopes; Snow Density; Siple Dome; GROUND-BASED OBSERVATIONS", "locations": "Antarctic; Siple Dome", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Kreutz, Karl; Mayewski, Paul A.", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Siple Dome Deep Ice Core Glaciochemistry and Regional Survey - A Contribution to the WAIS Initiative", "uid": "p0000012", "west": null}]

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