{"dp_type": "Project", "free_text": "outflow"}
[{"awards": "2123491 John, Seth; 2123354 Conway, Timothy; 2123333 Fitzsimmons, Jessica", "bounds_geometry": "POLYGON((-135 -66,-131.5 -66,-128 -66,-124.5 -66,-121 -66,-117.5 -66,-114 -66,-110.5 -66,-107 -66,-103.5 -66,-100 -66,-100 -67,-100 -68,-100 -69,-100 -70,-100 -71,-100 -72,-100 -73,-100 -74,-100 -75,-100 -76,-103.5 -76,-107 -76,-110.5 -76,-114 -76,-117.5 -76,-121 -76,-124.5 -76,-128 -76,-131.5 -76,-135 -76,-135 -75,-135 -74,-135 -73,-135 -72,-135 -71,-135 -70,-135 -69,-135 -68,-135 -67,-135 -66))", "dataset_titles": null, "datasets": null, "date_created": "Thu, 08 Sep 2022 00:00:00 GMT", "description": "The goal of the international GEOTRACES program is to understand the distributions of trace chemical elements and their isotopes (TEIs) in the oceans. Many trace metals such as iron are essential for life and thus considered nutrients for phytoplankton growth, with trace metal cycling being especially important for influencing carbon cycling in the iron-limited Southern Ocean, where episodic supply of iron from a range of different external sources is important. The primary goal of this project is to measure the dissolved concentrations, size partitioning, and dissolved isotope signature of Fe on a transect of water-column stations throughout the Amundsen Sea and surrounding region of the Antarctic Margin, as part of the GP17-ANT Expedition. The secondary goal of this project is to analyze the concentrations and size partitioning of the trace metals manganese, zinc, copper, cadmium, nickel, and lead in all water-column samples, measure the isotope ratios of zinc, cadmium, nickel, and copper in a subset of water column samples, and measure the Fe isotopic signature of aerosols, porewaters, and particles. Observations from this project will be incorporated into regional and global biogeochemistry models to assess TEI cycling within the Amundsen Sea and implications for the wider Southern Ocean. This project spans three institutions, four graduate students, undergraduate students, and will provide ultrafiltered samples and data to other PIs as service.\r\n\r\nThe US GEOTRACES GP17 ANT expedition, planned for austral summer 2023/2024 aims to determine the distribution and cycling of trace elements and their isotopes in the Amundsen Sea Sector (100-135\u00b0W) of the Antarctic Margin. The cruise will follow the Amundsen Sea \u2018conveyor belt\u2019 by sampling waters coming from the Antarctic Circumpolar Current onto the continental shelf, including near the Dotson and Pine Island ice shelves, the productive Amundsen Sea Polynya (ASP), and outflowing waters. Episodic addition of dissolved Fe and other TEIs from dust, ice-shelves, melting ice, and sediments drive seasonal primary productivity and carbon export over the Antarctic shelf and offshore into Southern Ocean. Seasonal coastal polynyas such as the highly productive ASP thus act as key levers on global carbon cycling. However, field observations of TEIs in such regions remain scarce, and biogeochemical cycling processes are poorly captured in models of ocean biogeochemistry. The investigators will use their combined analytical toolbox, in collaboration with the diagnostic chemical tracers and regional models of other funded groups to address four main objectives: 1) What is the relative importance of different sources in supplying Fe and other TEIs to the ASP? 2) What is the physiochemical speciation of this Fe, and its potential for transport? 3) How do biological uptake, scavenging and regeneration in the ASP influence TEI distributions, stoichiometry, and nutrient limitation? 4) What is the flux and signature of TEIs transported offshore to the ACC and Southern Ocean?", "east": -100.0, "geometry": "POINT(-117.5 -71)", "instruments": null, "is_usap_dc": true, "keywords": "R/V NBP; Amundsen Sea; TRACE ELEMENTS; BIOGEOCHEMICAL CYCLES", "locations": "Amundsen Sea", "north": -66.0, "nsf_funding_programs": "Chemical Oceanography; Chemical Oceanography; Chemical Oceanography", "paleo_time": null, "persons": "Conway, Timothy; Fitzsimmons, Jessica; John, Seth", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repositories": null, "science_programs": null, "south": -76.0, "title": "Collaborative Research: US GEOTRACES GP17-ANT: Dissolved concentrations, isotopes, and colloids of the bioactive trace metals", "uid": "p0010374", "west": -135.0}, {"awards": "1945127 Moffat, Carlos", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Fri, 03 Jun 2022 00:00:00 GMT", "description": "Freshwater discharges from melting high-latitude continental ice glacial reserves strongly control salt budgets, circulation and associated ocean water mass formation arising from polar ice shelves. These are different in nature than freshwater inputs associated with riverine coastal inputs. The PI proposes an observational deployment to measure a specific, previously-identified example of a coastal freshwater-driven current, the Antarctic Peninsula Coastal Current (APCC). \u003cbr/\u003e \u003cbr/\u003eThe research component of this CAREER project aims to improve understanding of the dynamics of freshwater discharge around the Antarctic continent. Associated research questions pertain to the i) controls on the cross- and along-shelf spreading of fresh, buoyant coastal currents, ii) the role of distributed coastal freshwater sources (as opposed to \u0027point\u0027 source river outflow sources typical of lower latitudes), and iii) the contribution of these coastal currents to water mass transformation and heat transfer on the continental shelf. An educational CAREER program component leverages a series of field experiences and research outputs including data, model outputs, and theory, to bring polar science to the classroom and the general public, as well as training a new polar scientist. This combined strategy will allow the investigator to lay the foundation for a successful academic career as a researcher and teacher at the University of Delaware. The project will also provide the opportunity to train a PhD student. Informal outreach efforts will include giving public lectures at University of Deleware\u0027s sponsored events, including Coast Day, a summer event that attracts 8000-10000 people, and remote lectures from the field using an existing outreach network. This proposal requires fieldwork in the Antarctic.\u003cbr/\u003e\u003cbr/\u003eThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Antarctic Peninsula; R/V LMG; AMD; USA/NSF; TURBULENCE; HEAT FLUX; AMD/US; USAP-DC; OCEAN CURRENTS", "locations": "Antarctic Peninsula", "north": null, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Moffat, Carlos", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG", "repositories": null, "science_programs": null, "south": null, "title": "CAREER: The Transformation, Cross-shore Export, and along-shore Transport of Freshwater on Antarctic Shelves", "uid": "p0010330", "west": null}, {"awards": "1941327 Stammerjohn, Sharon; 1941304 Sherrell, Robert; 1941292 St-Laurent, Pierre; 1941483 Yager, Patricia; 1941308 Fitzsimmons, Jessica", "bounds_geometry": "POLYGON((-120 -71,-118 -71,-116 -71,-114 -71,-112 -71,-110 -71,-108 -71,-106 -71,-104 -71,-102 -71,-100 -71,-100 -71.4,-100 -71.8,-100 -72.2,-100 -72.6,-100 -73,-100 -73.4,-100 -73.8,-100 -74.2,-100 -74.6,-100 -75,-102 -75,-104 -75,-106 -75,-108 -75,-110 -75,-112 -75,-114 -75,-116 -75,-118 -75,-120 -75,-120 -74.6,-120 -74.2,-120 -73.8,-120 -73.4,-120 -73,-120 -72.6,-120 -72.2,-120 -71.8,-120 -71.4,-120 -71))", "dataset_titles": "Expedition Data of NBP2202", "datasets": [{"dataset_uid": "200311", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data of NBP2202", "url": "https://www.rvdata.us/search/cruise/NBP2202"}], "date_created": "Fri, 20 Aug 2021 00:00:00 GMT", "description": " The Amundsen Sea hosts the most productive polynya in all of Antarctica, with its vibrant green waters visible from space, and an atmospheric CO2 uptake density 10x higher than the Southern Ocean average. The region is vulnerable to climate change, experiencing rapid losses in sea ice, a changing icescape, and some of the fastest melting glaciers flowing from the West Antarctic Ice Sheet (WAIS). ARTEMIS aims to characterize the climate-sensitive nature of glacial meltwater-driven micronutrient (iron, Fe) contributions driving ecosystem productivity and CO2 uptake in the coastal Antarctic. We propose to integrate observations and ocean modeling of these processes to enhance predictive capabilities. Currently, basal melt resulting from warm deep waters penetrating ice shelf cavities dominates mass losses of WAIS, contributing to sea level rise. These physical melting processes are being studied by the International Thwaites Glacier Collaboration (ITGC). The impact of melting on the marine ecosystem has also been explored, and we know that productivity is due in part to Fe-rich, glacial meltwater-driven outflow. The biogeochemical composition of the outflow from the glaciers surrounding the Amundsen Sea is largely unstudied, however. Improved knowledge would provide keys to understanding meltwater\u0027s future impact on the ecosystem. An ongoing field program (TARSAN, part of the ITGC) offers the ideal physical oceanographic framework for our biogeochemical effort. We propose here to collaborate with TARSAN-supported UK scientists, providing value added to both team efforts. ARTEMIS will add shipboard measurements (trace metals, carbonate system, nutrients, organic matter, microorganisms) and biogeochemical sensors on autonomous vehicles to gather critical knowledge needed to understand the impact of the melting WAIS on both the coastal ecosystem and the regional carbon (C) cycle. Driving questions include: 1) what are the fluxes and chemical forms of Fe, C, and microorganisms in the ice shelf outflow? 2) what are the relative contributions to the ouflow from deep water, benthic, and glacial melt sources, and how do these inputs combine to affect the bioavailability of Fe? 3) How are Fe and C compounds modified as the outflow advects along the coastal current and mixes into the bloom region? and 4) what will be the effect of increased glacial melting, changes in the coastal icescape, and declining sea ice on theecosystem of the Amundsen Sea? Such questions fall outside the focus of the ITGC, but are of keen interest to Antarctic Organisms and Ecosystems and Antarctic Integrated System Science programs.", "east": -100.0, "geometry": "POINT(-110 -73)", "instruments": null, "is_usap_dc": true, "keywords": "AMD; Amundsen Sea; AMD/US; BIOGEOCHEMICAL CYCLES; SHIPS; USA/NSF; USAP-DC", "locations": "Amundsen Sea", "north": -71.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Yager, Patricia; Medeiros, Patricia; Sherrell, Robert; St-Laurent, Pierre; Fitzsimmons, Jessica; Stammerjohn, Sharon", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e SHIPS", "repo": "R2R", "repositories": "Other", "science_programs": "Thwaites (ITGC)", "south": -75.0, "title": "NSFGEO-NERC: Collaborative Research: Accelerating Thwaites Ecosystem Impacts for the Southern Ocean (ARTEMIS)", "uid": "p0010249", "west": -120.0}, {"awards": "2000992 Romans, Brian", "bounds_geometry": "POINT(-172.873074 -74.274008)", "dataset_titles": null, "datasets": null, "date_created": "Tue, 06 Jul 2021 00:00:00 GMT", "description": "Geological records from the Antarctic Ice Sheet (AIS) margin demonstrate that the ice sheet oscillated in response to orbital variations in insolation (i.e., ~400, 100, 41, and 20 kyr), and it appears to be more sensitive to specific frequencies that regulate mean annual insolation (i.e., 41-kyr obliquity), particularly when the ice sheet extends into marine environments and is impacted by ocean circulation. However, the relationship between orbital forcing and the production of Antarctic Bottom Water (AABW) is unconstrained. Thus, a knowledge gap exists in understanding how changing insolation impacts ice marginal and Southern Ocean conditions that directly influence ventilation of the global ocean. We hypothesize that insolation-driven changes directly affected the production and export of AABW to the Southern Ocean from the Pliocene through the Pleistocene. For example, obliquity amplification during the warmer Pliocene may have led to enhanced production and export of dense waters from the shelf due to reduced AIS extent, which, in turn, led to greater AABW outflow. To determine the relationship of AABW production to orbital regime, we plan to reconstruct both from a single, continuous record from the levee of Hillary Canyon, a major conduit of AABW outflow, on the Ross Sea continental rise. \r\n\r\nTo test our hypothesis, we will analyze sediment from IODP Site U1524 (recovered in 2018 during International Ocean Discovery Program Expedition 374) and focus on three data sets. (1) We will use the occurrence, frequency, and character of mm-scale turbidite beds as a proxy of dense-shelf-water cascading outflow and AABW production. We will estimate the down-slope flux via numerical modeling of turbidity current properties using morphology, grain size, and bed thickness as input parameters. (2) We will use grain-size data, physical properties, XRF core scanning, CT imaging, and hyperspectral imaging to guide lithofacies analysis to infer processes occurring during glacial, deglacial, and interglacial periods. Statistical techniques and optimization methods will be applied to test for astronomical forcing of sedimentary packages in order to provide a cyclostratigraphic framework and interpret the orbital-forcing regime. (3) We will use bulk sedimentary carbon and nitrogen abundance and isotope data to determine how relative contributions of terrigenous and marine organic matter change in response to orbital forcing. We will integrate these data with sedimentological records to deconvolve organic matter production from its deposition or remobilization due to AABW outflow as a function of the oscillating extent of the AIS. These data sets will be integrated into a unified chronostratigraphy to determine the relationship between AABW outflow and orbital-forcing scenarios under the varying climate regimes of the Plio-Pleistocene.\r\n", "east": -172.873074, "geometry": "POINT(-172.873074 -74.274008)", "instruments": null, "is_usap_dc": true, "keywords": "USAP-DC; LABORATORY; USA/NSF; SEDIMENTS; AMD/US; AMD; Ross Sea", "locations": "Ross Sea", "north": -74.274008, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Romans, Brian; Patterson, Molly; Ash, Jeanine; Kulhanek, Denise; Ash, Jeannie", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": -74.274008, "title": "COLLABORATIVE RESEARCH: Orbital-scale Variability of the West Antarctic Ice Sheet and the Formation of Bottom Water in the Ross Sea during the Pliocene-Pleistocene", "uid": "p0010227", "west": -172.873074}, {"awards": "9725024 Jacobs, Stanley", "bounds_geometry": "POLYGON((140 -65,141 -65,142 -65,143 -65,144 -65,145 -65,146 -65,147 -65,148 -65,149 -65,150 -65,150 -65.3,150 -65.6,150 -65.9,150 -66.2,150 -66.5,150 -66.8,150 -67.1,150 -67.4,150 -67.7,150 -68,149 -68,148 -68,147 -68,146 -68,145 -68,144 -68,143 -68,142 -68,141 -68,140 -68,140 -67.7,140 -67.4,140 -67.1,140 -66.8,140 -66.5,140 -66.2,140 -65.9,140 -65.6,140 -65.3,140 -65))", "dataset_titles": "Expedition Data; R/V Nathaniel B. Palmer NBP0008 - Expedition Data; \r\nSummer Oceanographic Measurements near the Mertz Polynya NBP0008", "datasets": [{"dataset_uid": "001885", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0008"}, {"dataset_uid": "200023", "doi": "10.7284/905461", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "R/V Nathaniel B. Palmer NBP0008 - Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0008"}, {"dataset_uid": "200022", "doi": "10.15784/601161 ", "keywords": null, "people": null, "repository": "USAP-DC", "science_program": null, "title": "\r\nSummer Oceanographic Measurements near the Mertz Polynya NBP0008", "url": "https://www.usap-dc.org/view/dataset/601161"}], "date_created": "Mon, 11 Mar 2019 00:00:00 GMT", "description": "This project will study the dynamics of Circumpolar Deep Water intruding on the continental shelf of the West Antarctic coast, and the effect of this intrusion on the production of cold, dense bottom water, and melting at the base of floating glaciers and ice tongues. It will concentrate on the Amundsen Sea shelf, specifically in the region of the Pine Island Glacier, the Thwaites Glacier, and the Getz Ice Shelf. Circumpolar Deep Water (CDW) is a relatively warm water mass (warmer than +1.0 deg Celsius) which is normally confined to the outer edge of the continental shelf by an oceanic front separating this water mass from colder and saltier shelf waters. In the Amundsen Sea however, the deeper parts of the continental shelf are filled with nearly undiluted CDW, which is mixed upward, delivering significant amounts of heat to the base of the floating glacier tongues and the ice shelf. The melt rate beneath the Pine Island Glacier averages ten meters of ice per year with local annual rates reaching twenty meters. By comparison, melt rates beneath the Ross Ice Shelf are typically twenty to forty centimeters of ice per year. In addition, both the Pine Island and the Thwaites Glacier are extremely fast-moving, and have a significant effect on the regional ice mass balance of West Antarctica. This project therefore has an important connection to antarctic glaciology, particularly in assessing the combined effect of global change on the antarctic environment. The particular objectives of the project are (1) to delineate the frontal structure on the continental shelf sufficiently to define quantitatively the major routes of CDW inflow, meltwater outflow, and the westward evolution of CDW influence; (2) to use the obtained data set to validate a three-dimensional model of sub-ice ocean circulation that is currently under construction, and (3) to refine the estiamtes of in situ melting on the mass balance of the antarctic ice sheet. The observational program will be carried out from the research vessel Nathaniel B. Palmer in February and March, 1999.", "east": 150.0, "geometry": "POINT(145 -66.5)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; WATER MASSES; USAP-DC; Antarctica; Southern Ocean", "locations": "Southern Ocean; Antarctica", "north": -65.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Jacobs, Stanley; Visbeck, Martin", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "R2R", "repositories": "Other; USAP-DC", "science_programs": null, "south": -68.0, "title": "Circumpolar Deep Water and the West Antarctic Ice Sheet", "uid": "p0010019", "west": 140.0}, {"awards": "0732983 Vernet, Maria; 0732625 Leventer, Amy; 0732651 Gordon, Arnold; 0732711 Smith, Craig; 0732655 Mosley-Thompson, Ellen; 0732602 Truffer, Martin", "bounds_geometry": "POLYGON((-68 -57.8,-66.78 -57.8,-65.56 -57.8,-64.34 -57.8,-63.12 -57.8,-61.9 -57.8,-60.68 -57.8,-59.46 -57.8,-58.24 -57.8,-57.02 -57.8,-55.8 -57.8,-55.8 -58.8,-55.8 -59.8,-55.8 -60.8,-55.8 -61.8,-55.8 -62.8,-55.8 -63.8,-55.8 -64.8,-55.8 -65.8,-55.8 -66.8,-55.8 -67.8,-57.02 -67.8,-58.24 -67.8,-59.46 -67.8,-60.68 -67.8,-61.9 -67.8,-63.12 -67.8,-64.34 -67.8,-65.56 -67.8,-66.78 -67.8,-68 -67.8,-68 -66.8,-68 -65.8,-68 -64.8,-68 -63.8,-68 -62.8,-68 -61.8,-68 -60.8,-68 -59.8,-68 -58.8,-68 -57.8))", "dataset_titles": "Abrupt Environmental Change in the Larsen Ice Shelf System (LARISSA) - Marine Ecosystems; Biology Species Abundance from the Larsen Ice Shelf acquired during the Nathaniel B. Palmer expeditions NBP1001 and NBP1203; Bruce Plateau Accumulation O18 2009-1900; Easten Antarctic Peninsula Surface Sediment Diatom Data; LMG13-11 JKC-1 Paleoceanographic data; Macrofauna Species Abundance Raw Data from the Larsen Ice Shelf acquired during the Nathaniel B. Palmer expedition NBP1001; Megafauna Species Abundance Raw Data from the Larsen Ice Shelf acquired during the Nathaniel B. Palmer expedition NBP1001; NBP1001 cruise data; NBP1203 cruise data; Processed CTD Data from the Larsen Ice Shelf in Antarctica acquired during the Nathaniel B. Palmer expedition NBP1001; Processed CTD Data from the Larsen Ice Shelf near Antarctica acquired during the Nathaniel B. Palmer expedition NBP1203; Processed ship-based LADCP Sonar Data from the Larsen Ice Shelf in Antarctica acquired during the Nathaniel B. Palmer expedition NBP1001; Processed ship-based LADCP Sonar Data from the Larsen Ice Shelf near Antarctica acquired during the Nathaniel B. Palmer expedition NBP1203; Radioisotope data (C-14 and Pb-210) from bulk sediments, Larsen A Ice Shelf; Sediment samples (full data link not provided)", "datasets": [{"dataset_uid": "600167", "doi": "10.15784/600167", "keywords": "Antarctica; Antarctic Peninsula; Bruce Plateau; Cryosphere; Glaciology; Ice Core Records; Isotope; LARISSA; Paleoclimate; Sample/Collection Description; Snow Accumulation", "people": "Thompson, Lonnie G.; Mosley-Thompson, Ellen", "repository": "USAP-DC", "science_program": "LARISSA", "title": "Bruce Plateau Accumulation O18 2009-1900", "url": "https://www.usap-dc.org/view/dataset/600167"}, {"dataset_uid": "000226", "doi": "", "keywords": null, "people": null, "repository": "MGDS", "science_program": null, "title": "Biology Species Abundance from the Larsen Ice Shelf acquired during the Nathaniel B. Palmer expeditions NBP1001 and NBP1203", "url": "https://doi.org/10.1594/ieda/320821"}, {"dataset_uid": "601211", "doi": "10.15784/601211", "keywords": "Antarctica; Antarctic Peninsula; Benthos; Biology; Cryosphere; Diatom; Geology/Geophysics - Other; LMG0502; Marine Geoscience; Marine Sediments; Microscope; NBP0003; NBP0107; NBP0603; NBP1203; R/V Nathaniel B. Palmer; Surface Sediment", "people": "Leventer, Amy", "repository": "USAP-DC", "science_program": "LARISSA", "title": "Easten Antarctic Peninsula Surface Sediment Diatom Data", "url": "https://www.usap-dc.org/view/dataset/601211"}, {"dataset_uid": "000145", "doi": "", "keywords": null, "people": null, "repository": "AMGRF", "science_program": null, "title": "Sediment samples (full data link not provided)", "url": "http://arf.fsu.edu/"}, {"dataset_uid": "601305", "doi": null, "keywords": "Antarctica; Antarctic Peninsula; Biology; Biosphere; Box Corer; Cryosphere; LARISSA; Larsen Ice Shelf; Macrofauna; Megafauna; NBP1001; Oceans; R/V Nathaniel B. Palmer; Seafloor Sampling; Species Abundance", "people": "Smith, Craig", "repository": "USAP-DC", "science_program": "LARISSA", "title": "Megafauna Species Abundance Raw Data from the Larsen Ice Shelf acquired during the Nathaniel B. Palmer expedition NBP1001", "url": "https://www.usap-dc.org/view/dataset/601305"}, {"dataset_uid": "601306", "doi": null, "keywords": "Antarctica; Antarctic Peninsula; Biology; Biosphere; Box Corer; Cryosphere; LARISSA; Larsen Ice Shelf; Macrofauna; NBP1001; Oceans; R/V Nathaniel B. Palmer; Seafloor Sampling; Species Abundance", "people": "Smith, Craig", "repository": "USAP-DC", "science_program": "LARISSA", "title": "Macrofauna Species Abundance Raw Data from the Larsen Ice Shelf acquired during the Nathaniel B. Palmer expedition NBP1001", "url": "https://www.usap-dc.org/view/dataset/601306"}, {"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": "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": "601336", "doi": "10.15784/601336", "keywords": "Antarctica; Carbon-14; Cryosphere; Larsen Ice Shelf; Lead-210; Marine Sediments; Radioisotope Analysis", "people": "Taylor, Richard; DeMaster, David", "repository": "USAP-DC", "science_program": "LARISSA", "title": "Radioisotope data (C-14 and Pb-210) from bulk sediments, Larsen A Ice Shelf", "url": "https://www.usap-dc.org/view/dataset/601336"}, {"dataset_uid": "601345", "doi": null, "keywords": "Antarctica; Antarctic Peninsula; Cryosphere; CTD; CTD Data; LARISSA; Larsen Ice Shelf; NBP1001; Oceans; Physical Oceanography; R/V Nathaniel B. Palmer; Salinity; Temperature", "people": "Gordon, Arnold; Huber, Bruce", "repository": "USAP-DC", "science_program": "LARISSA", "title": "Processed CTD Data from the Larsen Ice Shelf in Antarctica acquired during the Nathaniel B. Palmer expedition NBP1001", "url": "https://www.usap-dc.org/view/dataset/601345"}, {"dataset_uid": "601346", "doi": null, "keywords": "Antarctica; Antarctic Peninsula; Cryosphere; Current Measurements; LADCP; Larsen Ice Shelf; NBP1001; Oceans; Physical Oceanography; R/V Nathaniel B. Palmer", "people": "Gordon, Arnold; Huber, Bruce", "repository": "USAP-DC", "science_program": "LARISSA", "title": "Processed ship-based LADCP Sonar Data from the Larsen Ice Shelf in Antarctica acquired during the Nathaniel B. Palmer expedition NBP1001", "url": "https://www.usap-dc.org/view/dataset/601346"}, {"dataset_uid": "601347", "doi": null, "keywords": "Antarctica; Antarctic Peninsula; Cryosphere; Current Measurements; LADCP; LARISSA; Larsen Ice Shelf; NBP1203; Oceans; Physical Oceanography; R/V Nathaniel B. Palmer", "people": "Gordon, Arnold; Huber, Bruce", "repository": "USAP-DC", "science_program": null, "title": "Processed ship-based LADCP Sonar Data from the Larsen Ice Shelf near Antarctica acquired during the Nathaniel B. Palmer expedition NBP1203", "url": "https://www.usap-dc.org/view/dataset/601347"}, {"dataset_uid": "601348", "doi": null, "keywords": "Antarctica; Antarctic Peninsula; Cryosphere; CTD; CTD Data; LARISSA; Larsen Ice Shelf; NBP1203; Oceans; Physical Oceanography; R/V Nathaniel B. Palmer; Salinity; Temperature", "people": "Huber, Bruce; Gordon, Arnold", "repository": "USAP-DC", "science_program": null, "title": "Processed CTD Data from the Larsen Ice Shelf near Antarctica acquired during the Nathaniel B. Palmer expedition NBP1203", "url": "https://www.usap-dc.org/view/dataset/601348"}, {"dataset_uid": "601485", "doi": "10.15784/601485", "keywords": "Antarctica; Antarctic Peninsula; Cryosphere; Delta 13C; Delta 18O; Paleoceanography; Temperature", "people": "Shevenell, Amelia", "repository": "USAP-DC", "science_program": "LARISSA", "title": "LMG13-11 JKC-1 Paleoceanographic data", "url": "https://www.usap-dc.org/view/dataset/601485"}, {"dataset_uid": "600073", "doi": "10.15784/600073", "keywords": "Antarctica; Antarctic Peninsula; Araon1304; Biology; Biosphere; LARISSA; Larsen B Ice Shelf; NBP1001; NBP1203; Oceans; Physical Oceanography; Southern Ocean; Weddell Sea", "people": "Vernet, Maria", "repository": "USAP-DC", "science_program": "LARISSA", "title": "Abrupt Environmental Change in the Larsen Ice Shelf System (LARISSA) - Marine Ecosystems", "url": "https://www.usap-dc.org/view/dataset/600073"}], "date_created": "Thu, 01 Feb 2018 00:00:00 GMT", "description": "Like no other region on Earth, the northern Antarctic Peninsula represents a spectacular natural laboratory of climate change and provides the opportunity to study the record of past climate and ecological shifts alongside the present-day changes in one of the most rapidly warming regions on Earth. This award supports the cryospheric and oceano-graphic components of an integrated multi-disciplinary program to address these rapid and fundamental changes now taking place in Antarctic Peninsula (AP). By making use of a marine research platform (the RV NB Palmer and on-board helicopters) and additional logistical support from the Argentine Antarctic program, the project will bring glaciologists, oceanographers, marine geologists and biologists together, working collaboratively to address fundamentally interdisciplinary questions regarding climate change. The project will include gathering a new, high-resolution paleoclimate record from the Bruce Plateau of Graham Land, and using it to compare Holocene- and possibly glacial-epoch climate to the modern period; investigating the stability of the remaining Larsen Ice Shelf and rapid post-breakup glacier response ? in particular, the roles of surface melt and ice-ocean interactions in the speed-up and retreat; observing the contribution of, and response of, oceanographic systems to ice shelf disintegration and ice-glacier interactions. Helicopter support on board will allow access to a wide range of glacial and geological areas of interest adjacent to the Larsen embayment. At these locations, long-term in situ glacial monitoring, isostatic uplift, and ice flow GPS sites will be established, and high-resolution ice core records will be obtained using previously tested lightweight drilling equipment. Long-term monitoring of deep water outflow will, for the first time, be integrated into changes in ice shelf extent and thickness, bottom water formation, and multi-level circulation by linking near-source observations to distal sites of concentrated outflow. The broader impacts of this international, multidisciplinary effort are that it will significantly advance our understanding of linkages amongst the earth\u0027s systems in the Polar Regions, and are proposed with international participation (UK, Spain, Belgium, Germany and Argentina) and interdisciplinary engagement in the true spirit of the International Polar Year (IPY). It will also provide a means of engaging and educating the public in virtually all aspects of polar science and the effects of ongoing climate change. The research team has a long record of involving undergraduates in research, educating high-performing graduate students, and providing innovative and engaging outreach products to the K-12 education and public media forums. Moreover, forging the new links both in science and international Antarctic programs will provide a continuing legacy, beyond IPY, of improved understanding and cooperation in Antarctica.", "east": -55.8, "geometry": "POINT(-61.9 -62.8)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e BOX CORE; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e ICE AUGERS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e SNOW DENSITY CUTTER", "is_usap_dc": true, "keywords": "NBP1001; Paleoclimate; Megafauna; FIELD SURVEYS; Not provided; Antarctic Peninsula; USAP-DC; AMD; cryospheric; Antarctica; R/V NBP; Climate Change; FIELD INVESTIGATION; LABORATORY; Climate Variability; AMD/US; multi-disciplinary; USA/NSF; Ice Core; Holocene", "locations": "Antarctica; Antarctic Peninsula", "north": -57.8, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Organisms and Ecosystems", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE", "persons": "Truffer, Martin; Gordon, Arnold; Huber, Bruce; Mosley-Thompson, Ellen; Leventer, Amy; Vernet, Maria; Smith, Craig; Thompson, Lonnie G.", "platforms": "Not provided; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "MGDS; Other; USAP-DC", "science_programs": "LARISSA", "south": -67.8, "title": "Collaborative Research in IPY: Abrupt Environmental Change in the Larsen Ice Shelf System, a Multidisciplinary Approach -- Cryosphere and Oceans", "uid": "p0000101", "west": -68.0}, {"awards": "0125172 Gordon, Arnold", "bounds_geometry": null, "dataset_titles": "Expedition Data; Expedition data of NBP0302; Expedition data of NBP0304C; Expedition data of NBP0304D; Expedition data of NBP0402; Expedition data of NBP0408; Expedition data of NBP0501", "datasets": [{"dataset_uid": "002625", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0304D", "url": "https://www.rvdata.us/search/cruise/NBP0304D"}, {"dataset_uid": "001691", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0304C"}, {"dataset_uid": "002620", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0408", "url": "https://www.rvdata.us/search/cruise/NBP0408"}, {"dataset_uid": "001692", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0304D"}, {"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": "002629", "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": "002638", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0402", "url": "https://www.rvdata.us/search/cruise/NBP0402"}, {"dataset_uid": "002588", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0302", "url": "https://www.rvdata.us/search/cruise/NBP0302"}, {"dataset_uid": "002624", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0304C", "url": "https://www.rvdata.us/search/cruise/NBP0304C"}], "date_created": "Tue, 17 Jan 2012 00:00:00 GMT", "description": "This study will investigate how the Antarctic Slope Front and continental slope morphology determine the exchanges of mass, heat, and fresh water between the shelf and the deep ocean, in particular those leading to outflows of dense water into intermediate and deep layers of the adjacent basins and into the world ocean circulation \u003cbr/\u003eWhile the importance to the global ocean circulation and climate of cold water masses originating in the Antarctic is unquestioned, the processes by which these water masses enter the deep ocean circulation are not. The primary goal of this work therefore is to identify the principal physical processes that govern the transfer of shelf-modified dense water into intermediate and deep layers of the adjacent deep ocean. At the same time, it seeks to understand the compensatory poleward flow of waters from the oceanic regime. The upper continental slope has been identified as the critical gateway for the exchange of shelf and deep ocean waters. Here the topography, velocity and density fields associated with the nearly ubiquitous front must strongly influence the advective and turbulent transfer of water properties between the shelf and oceanic regimes. The study has four specific objectives: [1] Determine the mean frontal structure and the principal scales of variability, and estimate the role of the front on cross-slope exchanges and mixing of adjacent water masses; [2] Determine the influence of slope topography and bathymetry on frontal location and outflow of dense Shelf Water; [3] Establish the role of frontal instabilities, benthic boundary layer transports, tides and other oscillatory processes on cross-slope advection and fluxes; and [4] Assess the effect of diapycnal mixing, lateral mixing identified through intrusions, and nonlinearities in the equation of state on the rate of descent and the fate of outflowing, near-freezing Shelf Water.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e PRESSURE/HEIGHT METERS \u003e PRESSURE SENSORS; IN SITU/LABORATORY INSTRUMENTS \u003e SAMPLERS \u003e BOTTLES/FLASKS/JARS \u003e WATER BOTTLES; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e TURBIDITY METERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ADCP; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS", "is_usap_dc": false, "keywords": "R/V NBP", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Gordon, Arnold; Cande, Steven; Visbeck, Martin; Jacobs, Stanley", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "Other", "science_programs": null, "south": null, "title": "Collaborative Research: Anslope, Cross-slope Exchanges at the Antarctic Slope Front", "uid": "p0000807", "west": null}, {"awards": "9725024 Jacobs, Stanley", "bounds_geometry": null, "dataset_titles": "Expedition Data; Expedition data of NBP0001; Expedition data of NBP0008; Summer Oceanographic Measurements near the Mertz Polynya NBP0008", "datasets": [{"dataset_uid": "002598", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0001", "url": "https://www.rvdata.us/search/cruise/NBP0001"}, {"dataset_uid": "002599", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0008", "url": "https://www.rvdata.us/search/cruise/NBP0008"}, {"dataset_uid": "601161", "doi": "10.15784/601161 ", "keywords": "Antarctica; Cryosphere; CTD; CTD Data; Mertz Polynya; NBP0008; Oceans; Oxygen; Physical Oceanography; R/V Nathaniel B. Palmer; Salinity; Southern Ocean; Temperature", "people": "Mele, Phil; Jacobs, Stanley; Smethie, William M; Mortlock, R. A.", "repository": "USAP-DC", "science_program": null, "title": "Summer Oceanographic Measurements near the Mertz Polynya NBP0008", "url": "https://www.usap-dc.org/view/dataset/601161"}, {"dataset_uid": "001885", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0008"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "This project will study the dynamics of Circumpolar Deep Water intruding on the continental shelf of the West Antarctic coast, and the effect of this intrusion on the production of cold, dense bottom water, and melting at the base of floating glaciers and ice tongues. It will concentrate on the Amundsen Sea shelf, specifically in the region of the Pine Island Glacier, the Thwaites Glacier, and the Getz Ice Shelf. Circumpolar Deep Water (CDW) is a relatively warm water mass (warmer than +1.0 deg Celsius) which is normally confined to the outer edge of the continental shelf by an oceanic front separating this water mass from colder and saltier shelf waters. In the Amundsen Sea however, the deeper parts of the continental shelf are filled with nearly undiluted CDW, which is mixed upward, delivering significant amounts of heat to the base of the floating glacier tongues and the ice shelf. The melt rate beneath the Pine Island Glacier averages ten meters of ice per year with local annual rates reaching twenty meters. By comparison, melt rates beneath the Ross Ice Shelf are typically twenty to forty centimeters of ice per year. In addition, both the Pine Island and the Thwaites Glacier are extremely fast-moving, and have a significant effect on the regional ice mass balance of West Antarctica. This project therefore has an important connection to antarctic glaciology, particularly in assessing the combined effect of global change on the antarctic environment. The particular objectives of the project are (1) to delineate the frontal structure on the continental shelf sufficiently to define quantitatively the major routes of CDW inflow, meltwater outflow, and the westward evolution of CDW influence; (2) to use the obtained data set to validate a three-dimensional model of sub-ice ocean circulation that is currently under construction, and (3) to refine the estiamtes of in situ melting on the mass balance of the antarctic ice sheet. The observational program will be carried out from the research vessel Nathaniel B. Palmer in February and March, 1999. ***", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS", "is_usap_dc": false, "keywords": "R/V NBP", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Jacobs, Stanley", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "Other; USAP-DC", "science_programs": null, "south": null, "title": "Circumpolar Deep Water and the West Antarctic Ice Sheet", "uid": "p0000815", "west": null}, {"awards": "8915730 Foster, Theodore", "bounds_geometry": "POLYGON((-70.9 -52.3533,-67.79577 -52.3533,-64.69154 -52.3533,-61.58731 -52.3533,-58.48308 -52.3533,-55.37885 -52.3533,-52.27462 -52.3533,-49.17039 -52.3533,-46.06616 -52.3533,-42.96193 -52.3533,-39.8577 -52.3533,-39.8577 -53.78259,-39.8577 -55.21188,-39.8577 -56.64117,-39.8577 -58.07046,-39.8577 -59.49975,-39.8577 -60.92904,-39.8577 -62.35833,-39.8577 -63.78762,-39.8577 -65.21691,-39.8577 -66.6462,-42.96193 -66.6462,-46.06616 -66.6462,-49.17039 -66.6462,-52.27462 -66.6462,-55.37885 -66.6462,-58.48308 -66.6462,-61.58731 -66.6462,-64.69154 -66.6462,-67.79577 -66.6462,-70.9 -66.6462,-70.9 -65.21691,-70.9 -63.78762,-70.9 -62.35833,-70.9 -60.92904,-70.9 -59.49975,-70.9 -58.07046,-70.9 -56.64117,-70.9 -55.21188,-70.9 -53.78259,-70.9 -52.3533))", "dataset_titles": "Expedition Data", "datasets": [{"dataset_uid": "002310", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP9207"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "This project is a two-year investigation into the dynamics and processes of deep water mass formation in the western Weddell Sea, combining physical and chemical oceanographic techniques to produce a coherent picture of the importance of this unique region to the structure of the world ocean. In the global context, this area is a major water mass modification site, involving open ocean convective events, the continental margin, and the ice cover. At this time the various water types that combine to form Weddell Sea Deep Water and Antarctic Bottom Water, and the conditions under which these water masses form, are not known well enough to establish direct physical links and volumetric budgets. It is suspected that the outflow from the Weddell Sea is restricted to quite narrow boundary currents flowing near the base of the continental shelf, and consequently may be observed with conventional current meter moorings from the shelf into the deep ocean. Two oceanographic expeditions to the western Weddell Sea are planned as part of this study: the first in the 1990/91, and the second in 1991/92. The objectives will be to measure the flow of newly-formed bottom water and to explore the sinking process of near-surface waters in the open ocean to see how these affect the deep water flows. In the first year the primary objective will be to set out an array of eight current meters in the bottom water core, while a secondary objective will be to grapple for an existing array that was set out in early 1988 but could not be recovered in 1989 because Antarctic Program ship resources had to be diverted to deal with the oil spill at Palmer Station. In the second year the array will be retrieved. Hydrographic cruises in order to define the upper ocean temperatures and salinity structure in the outflow region where unusually large step structures have been found in the past. A chemistry program consistent with the objectives of the World Ocean Circulation Experiment (WOCE) and presently planned experiments in the South Atlantic Ocean, will be integrated into the cruises carried out under this project.", "east": -39.8577, "geometry": "POINT(-55.37885 -59.49975)", "instruments": null, "is_usap_dc": false, "keywords": "R/V NBP", "locations": null, "north": -52.3533, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Foster, Theodore; Foster, Ted", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "Other", "science_programs": null, "south": -66.6462, "title": "Antarctic Bottom Water Formation", "uid": "p0000654", "west": -70.9}, {"awards": "9528807 Gordon, Arnold", "bounds_geometry": "POLYGON((-69.58631 -52.35405,-66.572039 -52.35405,-63.557768 -52.35405,-60.543497 -52.35405,-57.529226 -52.35405,-54.514955 -52.35405,-51.500684 -52.35405,-48.486413 -52.35405,-45.472142 -52.35405,-42.457871 -52.35405,-39.4436 -52.35405,-39.4436 -53.54563,-39.4436 -54.73721,-39.4436 -55.92879,-39.4436 -57.12037,-39.4436 -58.31195,-39.4436 -59.50353,-39.4436 -60.69511,-39.4436 -61.88669,-39.4436 -63.07827,-39.4436 -64.26985,-42.457871 -64.26985,-45.472142 -64.26985,-48.486413 -64.26985,-51.500684 -64.26985,-54.514955 -64.26985,-57.529226 -64.26985,-60.543497 -64.26985,-63.557768 -64.26985,-66.572039 -64.26985,-69.58631 -64.26985,-69.58631 -63.07827,-69.58631 -61.88669,-69.58631 -60.69511,-69.58631 -59.50353,-69.58631 -58.31195,-69.58631 -57.12037,-69.58631 -55.92879,-69.58631 -54.73721,-69.58631 -53.54563,-69.58631 -52.35405))", "dataset_titles": "Expedition Data", "datasets": [{"dataset_uid": "002142", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP9705"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "9528807 Gordon The proposed project is part of a multi-institutional integrated study of the outflow of newly formed bottom water from the Weddell Sea and its dispersion into the South Atlantic Ocean. It builds upon earlier successful studies of the inflow of intermediate water masses into the Eastern Weddell Sea, their modification within the Weddell Gyre, and their interaction with bottom water formation processes in the western Weddell Sea. The study is called Deep Ocean Ventilation Through Antarctic Intermediate Layers (DOVETAIL) and includes six components involving hydrographic measurements, natural tracer experiments, and modeling studies. The study will be centered east of the Drake Passage where water masses from the Weddell Sea and the Scotia Sea come together in the Weddell-Scotia Confluence, and will be carried out in cooperation with the national antarctic programs of Germany and Spain. This particular component concerns observations of the temperature and salinity structure, as well as the chemical nature of the water column in the confluence region. The study has four related objectives. The first is to assess the quantity and the physical and chemical characteristics of Weddell Sea source waters for the confluence. The second is to describe the dominant processes associated with spreading and sinking of dense antarctic waters within the Weddell-Scotia Confluence. The third is to estimate the ventilation rate of the world ocean, and the fourth is to estimate seasonal fluctuations in the regional ocean transport and hydrographic structure and to assess the likely influence of seasonal to interannual variability on rates of ventilation by Weddell Sea waters. Ventilation of the deep ocean -- the rising of sub-surface water masses to the surface to be recharged with atmospheric gases and to give up heat to the atmosphere -- is a uniquely antarctic phenomenon that has significant consequences for global change by affecting the g lobal reservoir of carbon dioxide, and by modulating the amount and extent of seasonal sea ice in the southern hemisphere. This component will make systematic observations of the temperature salinity structure of the water and undertake an extensive sampling program for other chemical studies. The purpose is to identify the individual water masses and to relate their temperature and salinity characteristics to the modification processes within the Weddell Sea. ***", "east": -39.4436, "geometry": "POINT(-54.514955 -58.31195)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS", "is_usap_dc": false, "keywords": "R/V NBP", "locations": null, "north": -52.35405, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Gordon, Arnold", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "Other", "science_programs": null, "south": -64.26985, "title": "Deep Ocean Ventilation Through Antarctic Intermediate Layers (DOVETAIL)", "uid": "p0000630", "west": -69.58631}, {"awards": "9811427 Felbeck, Horst", "bounds_geometry": null, "dataset_titles": "Expedition data of LMG9902", "datasets": [{"dataset_uid": "002716", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG9902", "url": "https://www.rvdata.us/search/cruise/LMG9902"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "Deception Island is a flooded caldera in the South Shetland Islands, Antarctica. The most recent eruption was in the 1970s causing the formation of new islands in the caldera and various other structures. It harbors many hot springs and fumaroles submerged in the caldera and intertidally. Sulfide and methane are prominent chemicals in the outflowing waters. Bacterial densities in the caldera reach unusually high values probably due to the input of reduced chemicals as energy sources. The environment around the springs resembles that found at hydrothermal vents where whole communities are based on the input of chemical energy by the hot waters. Similarities to hydrothermal vent environments include cold waters surrounding the hot springs resulting in large distances to the next warm water habitat and a lack of external food sources. The latter is due to ice cover during winter at Deception Island and the large distance to the euphotic zone at the vent sites. These parameters encourage the evolution of alternative ways to support life such as the establishment of a bacterial symbiosis. This Small Grant for Exploratory Research project will focus on an examination of the warm springs around Deception Island for the presence of marine invertebrates with chemoautotrophic symbionts. Maps will be made of any submerged fumaroles and of warm and hot springs in the intertidal zone. If animals are found near the fumaroles or in the hot springs, specimens will be collected. Collected specimens will be examined for the presence of chemoautotrophic bacteria and other adaptations to a hot sulfide- and methane-rich environment using enzyme text experimental incubations to analyze metabolic pathways and microscopic examination.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "R/V LMG", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Smith, Ken", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG", "repo": "R2R", "repositories": "Other", "science_programs": null, "south": null, "title": "Adaptations of Organisms at the Sulfide- and Methane-Containing Hydrothermal Areas of Deception Island, Antarctica", "uid": "p0000868", "west": null}, {"awards": "0538148 Huber, Bruce", "bounds_geometry": null, "dataset_titles": "Expedition Data; Expedition data of NBP0801; Processed CurrentMeter Data from the Adare Basin near Antarctica acquired during the Nathaniel B. Palmer expedition NBP1101 ; Processed CurrentMeter Data from the Ross Sea near Antarctica acquired during the Nathaniel B. Palmer expedition NBP0801", "datasets": [{"dataset_uid": "002647", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0801", "url": "https://www.rvdata.us/search/cruise/NBP0801"}, {"dataset_uid": "001517", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0801"}, {"dataset_uid": "601344", "doi": null, "keywords": "Antarctica; Cape Adare; Cryosphere; Mooring; mooring data; NBP0801; Physical Oceanography; Ross Sea; R/V Nathaniel B. Palmer; Salinity; Southern Ocean; Temperature", "people": "Gordon, Arnold; Huber, Bruce", "repository": "USAP-DC", "science_program": null, "title": "Processed CurrentMeter Data from the Ross Sea near Antarctica acquired during the Nathaniel B. Palmer expedition NBP0801", "url": "https://www.usap-dc.org/view/dataset/601344"}, {"dataset_uid": "601343", "doi": null, "keywords": "Antarctica; Cryosphere; Mooring; NBP1101; Ross Sea; Salinity; Southern Ocean; Temperature", "people": "Gordon, Arnold; Huber, Bruce", "repository": "USAP-DC", "science_program": null, "title": "Processed CurrentMeter Data from the Adare Basin near Antarctica acquired during the Nathaniel B. Palmer expedition NBP1101 ", "url": "https://www.usap-dc.org/view/dataset/601343"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "An array of moorings will be deployed and maintained east of Cape Adare, Antarctica, at the northwestern corner of the Ross Sea to observe the properties of Antarctic Bottom Water (AABW) exiting the Ross Sea. This location has been identified from recent studies as an ideal place to make such measurements. Antarctic Bottom Water has the highest density of the major global water masses, and fills the deepest parts of the world\u0027s oceans. Because it obtains many of its characteristics during its contact with the atmosphere and with glacial ice along the continental margins of Antarctica, it is expected that changes in newly-formed AABW may represent an effective indicator for abrupt climate change. The heterogeneous nature of the source regions around Antarctica complicates the observation of newly-formed AABW properties. The two most important source regions for AABW are within the Weddell and the Ross Seas, with additional sources drawn from the east Antarctic margins. In the northwestern Weddell Sea, several programs have been undertaken in the last decade to monitor the long term variability of Weddell Sea Deep and Bottom Water, precursors of AABW originating from the Weddell Sea, however no such systematic efforts have yet been undertaken to make longterm measurements of outflow from the Ross Sea. The proposed study will significantly improve our knowledge of the long term variability in the outflow of deep and bottom water from the Ross Sea, and will provide the beginnings of a long-term monitoring effort which ultimately will allow detection of changes in the ocean in the context of global climate change. When joined with similar efforts ongoing in the Weddell Sea, long-term behavior and possible coupling of these two important sources of the ocean\u0027s deepest water mass can be examined in detail.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e PRESSURE/HEIGHT METERS \u003e PRESSURE SENSORS; 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": "R/V NBP", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Caron, Bruce", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "Other; USAP-DC", "science_programs": null, "south": null, "title": "Cape Adare Long-term Mooring (CALM)", "uid": "p0000838", "west": null}, {"awards": "0233303 Jacobs, Stanley", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Mon, 09 Jul 2007 00:00:00 GMT", "description": "Major portions of the Antarctic Ice Sheet float in the surrounding ocean, at the physical and intellectual boundaries of oceanography and glaciology. These ice shelves lose mass continuously by melting into the sea, and periodically by the calving of icebergs. Those losses are compensated by the outflow of grounded ice, and by surface accumulation and basal freezing. Ice shelf sources and sinks vary on several time scales, but their wastage terms are not yet well known. Reports of substantial ice shelf retreat, regional ocean freshening and increased ice velocity and thinning are of particular concern at a time of warming ocean temperatures in waters that have access to deep glacier grounding lines.\u003cbr/\u003eThis award supports a study of the attrition of Antarctic ice shelves, using recent ocean geochemical measurements and drawing on numerical modeling and remote sensing resources. In cooperation with associates at Columbia University and the British Antarctic Survey, measurements of chlorofluorocarbon, helium, neon and oxygen isotopes will be used to infer basal melting beneath the Ross Ice Shelf, and a combination of oceanographic and altimeter data will be used to investigate the mass balance of George VI Ice Shelf. Ocean and remote sensing observations will also be used to help refine numerical models of ice cavity circulations. The objectives are to reduce uncertainties between different estimates of basal melting and freezing, evaluate regional variability, and provide an update of an earlier assessment of circumpolar net melting.\u003cbr/\u003eA better knowledge of ice shelf attrition is essential to an improved understanding of ice shelf response to climate change. Large ice shelf calving events can alter the ocean circulation and sea ice formation, and can lead to logistics problems such as those recently experienced in the Ross Sea. Broader impacts include the role of ice shelf meltwater in freshening and stabilizing the upper ocean, and in the formation of Antarctic Bottom Water, which can be traced far into the North Atlantic. To the extent that ice shelf attrition influences the flow of grounded ice, this work also has implications for ice sheet stability and sea level rise.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "mass; Basal freezing; basal melting; Ross Ice Sheet; Ice shelf meltwater; Ice Sheet; ice sheet stability; George VI Ice Shelf; Not provided; numerical modeling; Oceanography; Ice Velocity; Glaciology; Sea Level Rise; outflow; ice cavity circulations", "locations": "Ross Ice Sheet", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Jacobs, Stanley", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": null, "title": "Melting and Calving of Antarctic Ice Shelves", "uid": "p0000730", "west": null}]
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Project Title/Abstract/Map | NSF Award(s) | Date Created | PIs / Scientists | Dataset Links and Repositories | Abstract | Bounds Geometry | Geometry | Selected | Visible | |||||||||
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Collaborative Research: US GEOTRACES GP17-ANT: Dissolved concentrations, isotopes, and colloids of the bioactive trace metals
|
2123491 2123354 2123333 |
2022-09-08 | Conway, Timothy; Fitzsimmons, Jessica; John, Seth | No dataset link provided | The goal of the international GEOTRACES program is to understand the distributions of trace chemical elements and their isotopes (TEIs) in the oceans. Many trace metals such as iron are essential for life and thus considered nutrients for phytoplankton growth, with trace metal cycling being especially important for influencing carbon cycling in the iron-limited Southern Ocean, where episodic supply of iron from a range of different external sources is important. The primary goal of this project is to measure the dissolved concentrations, size partitioning, and dissolved isotope signature of Fe on a transect of water-column stations throughout the Amundsen Sea and surrounding region of the Antarctic Margin, as part of the GP17-ANT Expedition. The secondary goal of this project is to analyze the concentrations and size partitioning of the trace metals manganese, zinc, copper, cadmium, nickel, and lead in all water-column samples, measure the isotope ratios of zinc, cadmium, nickel, and copper in a subset of water column samples, and measure the Fe isotopic signature of aerosols, porewaters, and particles. Observations from this project will be incorporated into regional and global biogeochemistry models to assess TEI cycling within the Amundsen Sea and implications for the wider Southern Ocean. This project spans three institutions, four graduate students, undergraduate students, and will provide ultrafiltered samples and data to other PIs as service. The US GEOTRACES GP17 ANT expedition, planned for austral summer 2023/2024 aims to determine the distribution and cycling of trace elements and their isotopes in the Amundsen Sea Sector (100-135°W) of the Antarctic Margin. The cruise will follow the Amundsen Sea ‘conveyor belt’ by sampling waters coming from the Antarctic Circumpolar Current onto the continental shelf, including near the Dotson and Pine Island ice shelves, the productive Amundsen Sea Polynya (ASP), and outflowing waters. Episodic addition of dissolved Fe and other TEIs from dust, ice-shelves, melting ice, and sediments drive seasonal primary productivity and carbon export over the Antarctic shelf and offshore into Southern Ocean. Seasonal coastal polynyas such as the highly productive ASP thus act as key levers on global carbon cycling. However, field observations of TEIs in such regions remain scarce, and biogeochemical cycling processes are poorly captured in models of ocean biogeochemistry. The investigators will use their combined analytical toolbox, in collaboration with the diagnostic chemical tracers and regional models of other funded groups to address four main objectives: 1) What is the relative importance of different sources in supplying Fe and other TEIs to the ASP? 2) What is the physiochemical speciation of this Fe, and its potential for transport? 3) How do biological uptake, scavenging and regeneration in the ASP influence TEI distributions, stoichiometry, and nutrient limitation? 4) What is the flux and signature of TEIs transported offshore to the ACC and Southern Ocean? | POLYGON((-135 -66,-131.5 -66,-128 -66,-124.5 -66,-121 -66,-117.5 -66,-114 -66,-110.5 -66,-107 -66,-103.5 -66,-100 -66,-100 -67,-100 -68,-100 -69,-100 -70,-100 -71,-100 -72,-100 -73,-100 -74,-100 -75,-100 -76,-103.5 -76,-107 -76,-110.5 -76,-114 -76,-117.5 -76,-121 -76,-124.5 -76,-128 -76,-131.5 -76,-135 -76,-135 -75,-135 -74,-135 -73,-135 -72,-135 -71,-135 -70,-135 -69,-135 -68,-135 -67,-135 -66)) | POINT(-117.5 -71) | false | false | |||||||||
CAREER: The Transformation, Cross-shore Export, and along-shore Transport of Freshwater on Antarctic Shelves
|
1945127 |
2022-06-03 | Moffat, Carlos | No dataset link provided | Freshwater discharges from melting high-latitude continental ice glacial reserves strongly control salt budgets, circulation and associated ocean water mass formation arising from polar ice shelves. These are different in nature than freshwater inputs associated with riverine coastal inputs. The PI proposes an observational deployment to measure a specific, previously-identified example of a coastal freshwater-driven current, the Antarctic Peninsula Coastal Current (APCC). <br/> <br/>The research component of this CAREER project aims to improve understanding of the dynamics of freshwater discharge around the Antarctic continent. Associated research questions pertain to the i) controls on the cross- and along-shelf spreading of fresh, buoyant coastal currents, ii) the role of distributed coastal freshwater sources (as opposed to 'point' source river outflow sources typical of lower latitudes), and iii) the contribution of these coastal currents to water mass transformation and heat transfer on the continental shelf. An educational CAREER program component leverages a series of field experiences and research outputs including data, model outputs, and theory, to bring polar science to the classroom and the general public, as well as training a new polar scientist. This combined strategy will allow the investigator to lay the foundation for a successful academic career as a researcher and teacher at the University of Delaware. The project will also provide the opportunity to train a PhD student. Informal outreach efforts will include giving public lectures at University of Deleware's sponsored events, including Coast Day, a summer event that attracts 8000-10000 people, and remote lectures from the field using an existing outreach network. This proposal requires fieldwork in the Antarctic.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria. | None | None | false | false | |||||||||
NSFGEO-NERC: Collaborative Research: Accelerating Thwaites Ecosystem Impacts for the Southern Ocean (ARTEMIS)
|
1941327 1941304 1941292 1941483 1941308 |
2021-08-20 | Yager, Patricia; Medeiros, Patricia; Sherrell, Robert; St-Laurent, Pierre; Fitzsimmons, Jessica; Stammerjohn, Sharon |
|
The Amundsen Sea hosts the most productive polynya in all of Antarctica, with its vibrant green waters visible from space, and an atmospheric CO2 uptake density 10x higher than the Southern Ocean average. The region is vulnerable to climate change, experiencing rapid losses in sea ice, a changing icescape, and some of the fastest melting glaciers flowing from the West Antarctic Ice Sheet (WAIS). ARTEMIS aims to characterize the climate-sensitive nature of glacial meltwater-driven micronutrient (iron, Fe) contributions driving ecosystem productivity and CO2 uptake in the coastal Antarctic. We propose to integrate observations and ocean modeling of these processes to enhance predictive capabilities. Currently, basal melt resulting from warm deep waters penetrating ice shelf cavities dominates mass losses of WAIS, contributing to sea level rise. These physical melting processes are being studied by the International Thwaites Glacier Collaboration (ITGC). The impact of melting on the marine ecosystem has also been explored, and we know that productivity is due in part to Fe-rich, glacial meltwater-driven outflow. The biogeochemical composition of the outflow from the glaciers surrounding the Amundsen Sea is largely unstudied, however. Improved knowledge would provide keys to understanding meltwater's future impact on the ecosystem. An ongoing field program (TARSAN, part of the ITGC) offers the ideal physical oceanographic framework for our biogeochemical effort. We propose here to collaborate with TARSAN-supported UK scientists, providing value added to both team efforts. ARTEMIS will add shipboard measurements (trace metals, carbonate system, nutrients, organic matter, microorganisms) and biogeochemical sensors on autonomous vehicles to gather critical knowledge needed to understand the impact of the melting WAIS on both the coastal ecosystem and the regional carbon (C) cycle. Driving questions include: 1) what are the fluxes and chemical forms of Fe, C, and microorganisms in the ice shelf outflow? 2) what are the relative contributions to the ouflow from deep water, benthic, and glacial melt sources, and how do these inputs combine to affect the bioavailability of Fe? 3) How are Fe and C compounds modified as the outflow advects along the coastal current and mixes into the bloom region? and 4) what will be the effect of increased glacial melting, changes in the coastal icescape, and declining sea ice on theecosystem of the Amundsen Sea? Such questions fall outside the focus of the ITGC, but are of keen interest to Antarctic Organisms and Ecosystems and Antarctic Integrated System Science programs. | POLYGON((-120 -71,-118 -71,-116 -71,-114 -71,-112 -71,-110 -71,-108 -71,-106 -71,-104 -71,-102 -71,-100 -71,-100 -71.4,-100 -71.8,-100 -72.2,-100 -72.6,-100 -73,-100 -73.4,-100 -73.8,-100 -74.2,-100 -74.6,-100 -75,-102 -75,-104 -75,-106 -75,-108 -75,-110 -75,-112 -75,-114 -75,-116 -75,-118 -75,-120 -75,-120 -74.6,-120 -74.2,-120 -73.8,-120 -73.4,-120 -73,-120 -72.6,-120 -72.2,-120 -71.8,-120 -71.4,-120 -71)) | POINT(-110 -73) | false | false | |||||||||
COLLABORATIVE RESEARCH: Orbital-scale Variability of the West Antarctic Ice Sheet and the Formation of Bottom Water in the Ross Sea during the Pliocene-Pleistocene
|
2000992 |
2021-07-06 | Romans, Brian; Patterson, Molly; Ash, Jeanine; Kulhanek, Denise; Ash, Jeannie | No dataset link provided | Geological records from the Antarctic Ice Sheet (AIS) margin demonstrate that the ice sheet oscillated in response to orbital variations in insolation (i.e., ~400, 100, 41, and 20 kyr), and it appears to be more sensitive to specific frequencies that regulate mean annual insolation (i.e., 41-kyr obliquity), particularly when the ice sheet extends into marine environments and is impacted by ocean circulation. However, the relationship between orbital forcing and the production of Antarctic Bottom Water (AABW) is unconstrained. Thus, a knowledge gap exists in understanding how changing insolation impacts ice marginal and Southern Ocean conditions that directly influence ventilation of the global ocean. We hypothesize that insolation-driven changes directly affected the production and export of AABW to the Southern Ocean from the Pliocene through the Pleistocene. For example, obliquity amplification during the warmer Pliocene may have led to enhanced production and export of dense waters from the shelf due to reduced AIS extent, which, in turn, led to greater AABW outflow. To determine the relationship of AABW production to orbital regime, we plan to reconstruct both from a single, continuous record from the levee of Hillary Canyon, a major conduit of AABW outflow, on the Ross Sea continental rise. To test our hypothesis, we will analyze sediment from IODP Site U1524 (recovered in 2018 during International Ocean Discovery Program Expedition 374) and focus on three data sets. (1) We will use the occurrence, frequency, and character of mm-scale turbidite beds as a proxy of dense-shelf-water cascading outflow and AABW production. We will estimate the down-slope flux via numerical modeling of turbidity current properties using morphology, grain size, and bed thickness as input parameters. (2) We will use grain-size data, physical properties, XRF core scanning, CT imaging, and hyperspectral imaging to guide lithofacies analysis to infer processes occurring during glacial, deglacial, and interglacial periods. Statistical techniques and optimization methods will be applied to test for astronomical forcing of sedimentary packages in order to provide a cyclostratigraphic framework and interpret the orbital-forcing regime. (3) We will use bulk sedimentary carbon and nitrogen abundance and isotope data to determine how relative contributions of terrigenous and marine organic matter change in response to orbital forcing. We will integrate these data with sedimentological records to deconvolve organic matter production from its deposition or remobilization due to AABW outflow as a function of the oscillating extent of the AIS. These data sets will be integrated into a unified chronostratigraphy to determine the relationship between AABW outflow and orbital-forcing scenarios under the varying climate regimes of the Plio-Pleistocene. | POINT(-172.873074 -74.274008) | POINT(-172.873074 -74.274008) | false | false | |||||||||
Circumpolar Deep Water and the West Antarctic Ice Sheet
|
9725024 |
2019-03-11 | Jacobs, Stanley; Visbeck, Martin |
|
This project will study the dynamics of Circumpolar Deep Water intruding on the continental shelf of the West Antarctic coast, and the effect of this intrusion on the production of cold, dense bottom water, and melting at the base of floating glaciers and ice tongues. It will concentrate on the Amundsen Sea shelf, specifically in the region of the Pine Island Glacier, the Thwaites Glacier, and the Getz Ice Shelf. Circumpolar Deep Water (CDW) is a relatively warm water mass (warmer than +1.0 deg Celsius) which is normally confined to the outer edge of the continental shelf by an oceanic front separating this water mass from colder and saltier shelf waters. In the Amundsen Sea however, the deeper parts of the continental shelf are filled with nearly undiluted CDW, which is mixed upward, delivering significant amounts of heat to the base of the floating glacier tongues and the ice shelf. The melt rate beneath the Pine Island Glacier averages ten meters of ice per year with local annual rates reaching twenty meters. By comparison, melt rates beneath the Ross Ice Shelf are typically twenty to forty centimeters of ice per year. In addition, both the Pine Island and the Thwaites Glacier are extremely fast-moving, and have a significant effect on the regional ice mass balance of West Antarctica. This project therefore has an important connection to antarctic glaciology, particularly in assessing the combined effect of global change on the antarctic environment. The particular objectives of the project are (1) to delineate the frontal structure on the continental shelf sufficiently to define quantitatively the major routes of CDW inflow, meltwater outflow, and the westward evolution of CDW influence; (2) to use the obtained data set to validate a three-dimensional model of sub-ice ocean circulation that is currently under construction, and (3) to refine the estiamtes of in situ melting on the mass balance of the antarctic ice sheet. The observational program will be carried out from the research vessel Nathaniel B. Palmer in February and March, 1999. | POLYGON((140 -65,141 -65,142 -65,143 -65,144 -65,145 -65,146 -65,147 -65,148 -65,149 -65,150 -65,150 -65.3,150 -65.6,150 -65.9,150 -66.2,150 -66.5,150 -66.8,150 -67.1,150 -67.4,150 -67.7,150 -68,149 -68,148 -68,147 -68,146 -68,145 -68,144 -68,143 -68,142 -68,141 -68,140 -68,140 -67.7,140 -67.4,140 -67.1,140 -66.8,140 -66.5,140 -66.2,140 -65.9,140 -65.6,140 -65.3,140 -65)) | POINT(145 -66.5) | false | false | |||||||||
Collaborative Research in IPY: Abrupt Environmental Change in the Larsen Ice Shelf System, a Multidisciplinary Approach -- Cryosphere and Oceans
|
0732983 0732625 0732651 0732711 0732655 0732602 |
2018-02-01 | Truffer, Martin; Gordon, Arnold; Huber, Bruce; Mosley-Thompson, Ellen; Leventer, Amy; Vernet, Maria; Smith, Craig; Thompson, Lonnie G. | Like no other region on Earth, the northern Antarctic Peninsula represents a spectacular natural laboratory of climate change and provides the opportunity to study the record of past climate and ecological shifts alongside the present-day changes in one of the most rapidly warming regions on Earth. This award supports the cryospheric and oceano-graphic components of an integrated multi-disciplinary program to address these rapid and fundamental changes now taking place in Antarctic Peninsula (AP). By making use of a marine research platform (the RV NB Palmer and on-board helicopters) and additional logistical support from the Argentine Antarctic program, the project will bring glaciologists, oceanographers, marine geologists and biologists together, working collaboratively to address fundamentally interdisciplinary questions regarding climate change. The project will include gathering a new, high-resolution paleoclimate record from the Bruce Plateau of Graham Land, and using it to compare Holocene- and possibly glacial-epoch climate to the modern period; investigating the stability of the remaining Larsen Ice Shelf and rapid post-breakup glacier response ? in particular, the roles of surface melt and ice-ocean interactions in the speed-up and retreat; observing the contribution of, and response of, oceanographic systems to ice shelf disintegration and ice-glacier interactions. Helicopter support on board will allow access to a wide range of glacial and geological areas of interest adjacent to the Larsen embayment. At these locations, long-term in situ glacial monitoring, isostatic uplift, and ice flow GPS sites will be established, and high-resolution ice core records will be obtained using previously tested lightweight drilling equipment. Long-term monitoring of deep water outflow will, for the first time, be integrated into changes in ice shelf extent and thickness, bottom water formation, and multi-level circulation by linking near-source observations to distal sites of concentrated outflow. The broader impacts of this international, multidisciplinary effort are that it will significantly advance our understanding of linkages amongst the earth's systems in the Polar Regions, and are proposed with international participation (UK, Spain, Belgium, Germany and Argentina) and interdisciplinary engagement in the true spirit of the International Polar Year (IPY). It will also provide a means of engaging and educating the public in virtually all aspects of polar science and the effects of ongoing climate change. The research team has a long record of involving undergraduates in research, educating high-performing graduate students, and providing innovative and engaging outreach products to the K-12 education and public media forums. Moreover, forging the new links both in science and international Antarctic programs will provide a continuing legacy, beyond IPY, of improved understanding and cooperation in Antarctica. | POLYGON((-68 -57.8,-66.78 -57.8,-65.56 -57.8,-64.34 -57.8,-63.12 -57.8,-61.9 -57.8,-60.68 -57.8,-59.46 -57.8,-58.24 -57.8,-57.02 -57.8,-55.8 -57.8,-55.8 -58.8,-55.8 -59.8,-55.8 -60.8,-55.8 -61.8,-55.8 -62.8,-55.8 -63.8,-55.8 -64.8,-55.8 -65.8,-55.8 -66.8,-55.8 -67.8,-57.02 -67.8,-58.24 -67.8,-59.46 -67.8,-60.68 -67.8,-61.9 -67.8,-63.12 -67.8,-64.34 -67.8,-65.56 -67.8,-66.78 -67.8,-68 -67.8,-68 -66.8,-68 -65.8,-68 -64.8,-68 -63.8,-68 -62.8,-68 -61.8,-68 -60.8,-68 -59.8,-68 -58.8,-68 -57.8)) | POINT(-61.9 -62.8) | false | false | ||||||||||
Collaborative Research: Anslope, Cross-slope Exchanges at the Antarctic Slope Front
|
0125172 |
2012-01-17 | Gordon, Arnold; Cande, Steven; Visbeck, Martin; Jacobs, Stanley | This study will investigate how the Antarctic Slope Front and continental slope morphology determine the exchanges of mass, heat, and fresh water between the shelf and the deep ocean, in particular those leading to outflows of dense water into intermediate and deep layers of the adjacent basins and into the world ocean circulation <br/>While the importance to the global ocean circulation and climate of cold water masses originating in the Antarctic is unquestioned, the processes by which these water masses enter the deep ocean circulation are not. The primary goal of this work therefore is to identify the principal physical processes that govern the transfer of shelf-modified dense water into intermediate and deep layers of the adjacent deep ocean. At the same time, it seeks to understand the compensatory poleward flow of waters from the oceanic regime. The upper continental slope has been identified as the critical gateway for the exchange of shelf and deep ocean waters. Here the topography, velocity and density fields associated with the nearly ubiquitous front must strongly influence the advective and turbulent transfer of water properties between the shelf and oceanic regimes. The study has four specific objectives: [1] Determine the mean frontal structure and the principal scales of variability, and estimate the role of the front on cross-slope exchanges and mixing of adjacent water masses; [2] Determine the influence of slope topography and bathymetry on frontal location and outflow of dense Shelf Water; [3] Establish the role of frontal instabilities, benthic boundary layer transports, tides and other oscillatory processes on cross-slope advection and fluxes; and [4] Assess the effect of diapycnal mixing, lateral mixing identified through intrusions, and nonlinearities in the equation of state on the rate of descent and the fate of outflowing, near-freezing Shelf Water. | None | None | false | false | ||||||||||
Circumpolar Deep Water and the West Antarctic Ice Sheet
|
9725024 |
2010-05-04 | Jacobs, Stanley |
|
This project will study the dynamics of Circumpolar Deep Water intruding on the continental shelf of the West Antarctic coast, and the effect of this intrusion on the production of cold, dense bottom water, and melting at the base of floating glaciers and ice tongues. It will concentrate on the Amundsen Sea shelf, specifically in the region of the Pine Island Glacier, the Thwaites Glacier, and the Getz Ice Shelf. Circumpolar Deep Water (CDW) is a relatively warm water mass (warmer than +1.0 deg Celsius) which is normally confined to the outer edge of the continental shelf by an oceanic front separating this water mass from colder and saltier shelf waters. In the Amundsen Sea however, the deeper parts of the continental shelf are filled with nearly undiluted CDW, which is mixed upward, delivering significant amounts of heat to the base of the floating glacier tongues and the ice shelf. The melt rate beneath the Pine Island Glacier averages ten meters of ice per year with local annual rates reaching twenty meters. By comparison, melt rates beneath the Ross Ice Shelf are typically twenty to forty centimeters of ice per year. In addition, both the Pine Island and the Thwaites Glacier are extremely fast-moving, and have a significant effect on the regional ice mass balance of West Antarctica. This project therefore has an important connection to antarctic glaciology, particularly in assessing the combined effect of global change on the antarctic environment. The particular objectives of the project are (1) to delineate the frontal structure on the continental shelf sufficiently to define quantitatively the major routes of CDW inflow, meltwater outflow, and the westward evolution of CDW influence; (2) to use the obtained data set to validate a three-dimensional model of sub-ice ocean circulation that is currently under construction, and (3) to refine the estiamtes of in situ melting on the mass balance of the antarctic ice sheet. The observational program will be carried out from the research vessel Nathaniel B. Palmer in February and March, 1999. *** | None | None | false | false | |||||||||
Antarctic Bottom Water Formation
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8915730 |
2010-05-04 | Foster, Theodore; Foster, Ted |
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This project is a two-year investigation into the dynamics and processes of deep water mass formation in the western Weddell Sea, combining physical and chemical oceanographic techniques to produce a coherent picture of the importance of this unique region to the structure of the world ocean. In the global context, this area is a major water mass modification site, involving open ocean convective events, the continental margin, and the ice cover. At this time the various water types that combine to form Weddell Sea Deep Water and Antarctic Bottom Water, and the conditions under which these water masses form, are not known well enough to establish direct physical links and volumetric budgets. It is suspected that the outflow from the Weddell Sea is restricted to quite narrow boundary currents flowing near the base of the continental shelf, and consequently may be observed with conventional current meter moorings from the shelf into the deep ocean. Two oceanographic expeditions to the western Weddell Sea are planned as part of this study: the first in the 1990/91, and the second in 1991/92. The objectives will be to measure the flow of newly-formed bottom water and to explore the sinking process of near-surface waters in the open ocean to see how these affect the deep water flows. In the first year the primary objective will be to set out an array of eight current meters in the bottom water core, while a secondary objective will be to grapple for an existing array that was set out in early 1988 but could not be recovered in 1989 because Antarctic Program ship resources had to be diverted to deal with the oil spill at Palmer Station. In the second year the array will be retrieved. Hydrographic cruises in order to define the upper ocean temperatures and salinity structure in the outflow region where unusually large step structures have been found in the past. A chemistry program consistent with the objectives of the World Ocean Circulation Experiment (WOCE) and presently planned experiments in the South Atlantic Ocean, will be integrated into the cruises carried out under this project. | POLYGON((-70.9 -52.3533,-67.79577 -52.3533,-64.69154 -52.3533,-61.58731 -52.3533,-58.48308 -52.3533,-55.37885 -52.3533,-52.27462 -52.3533,-49.17039 -52.3533,-46.06616 -52.3533,-42.96193 -52.3533,-39.8577 -52.3533,-39.8577 -53.78259,-39.8577 -55.21188,-39.8577 -56.64117,-39.8577 -58.07046,-39.8577 -59.49975,-39.8577 -60.92904,-39.8577 -62.35833,-39.8577 -63.78762,-39.8577 -65.21691,-39.8577 -66.6462,-42.96193 -66.6462,-46.06616 -66.6462,-49.17039 -66.6462,-52.27462 -66.6462,-55.37885 -66.6462,-58.48308 -66.6462,-61.58731 -66.6462,-64.69154 -66.6462,-67.79577 -66.6462,-70.9 -66.6462,-70.9 -65.21691,-70.9 -63.78762,-70.9 -62.35833,-70.9 -60.92904,-70.9 -59.49975,-70.9 -58.07046,-70.9 -56.64117,-70.9 -55.21188,-70.9 -53.78259,-70.9 -52.3533)) | POINT(-55.37885 -59.49975) | false | false | |||||||||
Deep Ocean Ventilation Through Antarctic Intermediate Layers (DOVETAIL)
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9528807 |
2010-05-04 | Gordon, Arnold |
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9528807 Gordon The proposed project is part of a multi-institutional integrated study of the outflow of newly formed bottom water from the Weddell Sea and its dispersion into the South Atlantic Ocean. It builds upon earlier successful studies of the inflow of intermediate water masses into the Eastern Weddell Sea, their modification within the Weddell Gyre, and their interaction with bottom water formation processes in the western Weddell Sea. The study is called Deep Ocean Ventilation Through Antarctic Intermediate Layers (DOVETAIL) and includes six components involving hydrographic measurements, natural tracer experiments, and modeling studies. The study will be centered east of the Drake Passage where water masses from the Weddell Sea and the Scotia Sea come together in the Weddell-Scotia Confluence, and will be carried out in cooperation with the national antarctic programs of Germany and Spain. This particular component concerns observations of the temperature and salinity structure, as well as the chemical nature of the water column in the confluence region. The study has four related objectives. The first is to assess the quantity and the physical and chemical characteristics of Weddell Sea source waters for the confluence. The second is to describe the dominant processes associated with spreading and sinking of dense antarctic waters within the Weddell-Scotia Confluence. The third is to estimate the ventilation rate of the world ocean, and the fourth is to estimate seasonal fluctuations in the regional ocean transport and hydrographic structure and to assess the likely influence of seasonal to interannual variability on rates of ventilation by Weddell Sea waters. Ventilation of the deep ocean -- the rising of sub-surface water masses to the surface to be recharged with atmospheric gases and to give up heat to the atmosphere -- is a uniquely antarctic phenomenon that has significant consequences for global change by affecting the g lobal reservoir of carbon dioxide, and by modulating the amount and extent of seasonal sea ice in the southern hemisphere. This component will make systematic observations of the temperature salinity structure of the water and undertake an extensive sampling program for other chemical studies. The purpose is to identify the individual water masses and to relate their temperature and salinity characteristics to the modification processes within the Weddell Sea. *** | POLYGON((-69.58631 -52.35405,-66.572039 -52.35405,-63.557768 -52.35405,-60.543497 -52.35405,-57.529226 -52.35405,-54.514955 -52.35405,-51.500684 -52.35405,-48.486413 -52.35405,-45.472142 -52.35405,-42.457871 -52.35405,-39.4436 -52.35405,-39.4436 -53.54563,-39.4436 -54.73721,-39.4436 -55.92879,-39.4436 -57.12037,-39.4436 -58.31195,-39.4436 -59.50353,-39.4436 -60.69511,-39.4436 -61.88669,-39.4436 -63.07827,-39.4436 -64.26985,-42.457871 -64.26985,-45.472142 -64.26985,-48.486413 -64.26985,-51.500684 -64.26985,-54.514955 -64.26985,-57.529226 -64.26985,-60.543497 -64.26985,-63.557768 -64.26985,-66.572039 -64.26985,-69.58631 -64.26985,-69.58631 -63.07827,-69.58631 -61.88669,-69.58631 -60.69511,-69.58631 -59.50353,-69.58631 -58.31195,-69.58631 -57.12037,-69.58631 -55.92879,-69.58631 -54.73721,-69.58631 -53.54563,-69.58631 -52.35405)) | POINT(-54.514955 -58.31195) | false | false | |||||||||
Adaptations of Organisms at the Sulfide- and Methane-Containing Hydrothermal Areas of Deception Island, Antarctica
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9811427 |
2010-05-04 | Smith, Ken |
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Deception Island is a flooded caldera in the South Shetland Islands, Antarctica. The most recent eruption was in the 1970s causing the formation of new islands in the caldera and various other structures. It harbors many hot springs and fumaroles submerged in the caldera and intertidally. Sulfide and methane are prominent chemicals in the outflowing waters. Bacterial densities in the caldera reach unusually high values probably due to the input of reduced chemicals as energy sources. The environment around the springs resembles that found at hydrothermal vents where whole communities are based on the input of chemical energy by the hot waters. Similarities to hydrothermal vent environments include cold waters surrounding the hot springs resulting in large distances to the next warm water habitat and a lack of external food sources. The latter is due to ice cover during winter at Deception Island and the large distance to the euphotic zone at the vent sites. These parameters encourage the evolution of alternative ways to support life such as the establishment of a bacterial symbiosis. This Small Grant for Exploratory Research project will focus on an examination of the warm springs around Deception Island for the presence of marine invertebrates with chemoautotrophic symbionts. Maps will be made of any submerged fumaroles and of warm and hot springs in the intertidal zone. If animals are found near the fumaroles or in the hot springs, specimens will be collected. Collected specimens will be examined for the presence of chemoautotrophic bacteria and other adaptations to a hot sulfide- and methane-rich environment using enzyme text experimental incubations to analyze metabolic pathways and microscopic examination. | None | None | false | false | |||||||||
Cape Adare Long-term Mooring (CALM)
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0538148 |
2010-05-04 | Caron, Bruce | An array of moorings will be deployed and maintained east of Cape Adare, Antarctica, at the northwestern corner of the Ross Sea to observe the properties of Antarctic Bottom Water (AABW) exiting the Ross Sea. This location has been identified from recent studies as an ideal place to make such measurements. Antarctic Bottom Water has the highest density of the major global water masses, and fills the deepest parts of the world's oceans. Because it obtains many of its characteristics during its contact with the atmosphere and with glacial ice along the continental margins of Antarctica, it is expected that changes in newly-formed AABW may represent an effective indicator for abrupt climate change. The heterogeneous nature of the source regions around Antarctica complicates the observation of newly-formed AABW properties. The two most important source regions for AABW are within the Weddell and the Ross Seas, with additional sources drawn from the east Antarctic margins. In the northwestern Weddell Sea, several programs have been undertaken in the last decade to monitor the long term variability of Weddell Sea Deep and Bottom Water, precursors of AABW originating from the Weddell Sea, however no such systematic efforts have yet been undertaken to make longterm measurements of outflow from the Ross Sea. The proposed study will significantly improve our knowledge of the long term variability in the outflow of deep and bottom water from the Ross Sea, and will provide the beginnings of a long-term monitoring effort which ultimately will allow detection of changes in the ocean in the context of global climate change. When joined with similar efforts ongoing in the Weddell Sea, long-term behavior and possible coupling of these two important sources of the ocean's deepest water mass can be examined in detail. | None | None | false | false | ||||||||||
Melting and Calving of Antarctic Ice Shelves
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0233303 |
2007-07-09 | Jacobs, Stanley | No dataset link provided | Major portions of the Antarctic Ice Sheet float in the surrounding ocean, at the physical and intellectual boundaries of oceanography and glaciology. These ice shelves lose mass continuously by melting into the sea, and periodically by the calving of icebergs. Those losses are compensated by the outflow of grounded ice, and by surface accumulation and basal freezing. Ice shelf sources and sinks vary on several time scales, but their wastage terms are not yet well known. Reports of substantial ice shelf retreat, regional ocean freshening and increased ice velocity and thinning are of particular concern at a time of warming ocean temperatures in waters that have access to deep glacier grounding lines.<br/>This award supports a study of the attrition of Antarctic ice shelves, using recent ocean geochemical measurements and drawing on numerical modeling and remote sensing resources. In cooperation with associates at Columbia University and the British Antarctic Survey, measurements of chlorofluorocarbon, helium, neon and oxygen isotopes will be used to infer basal melting beneath the Ross Ice Shelf, and a combination of oceanographic and altimeter data will be used to investigate the mass balance of George VI Ice Shelf. Ocean and remote sensing observations will also be used to help refine numerical models of ice cavity circulations. The objectives are to reduce uncertainties between different estimates of basal melting and freezing, evaluate regional variability, and provide an update of an earlier assessment of circumpolar net melting.<br/>A better knowledge of ice shelf attrition is essential to an improved understanding of ice shelf response to climate change. Large ice shelf calving events can alter the ocean circulation and sea ice formation, and can lead to logistics problems such as those recently experienced in the Ross Sea. Broader impacts include the role of ice shelf meltwater in freshening and stabilizing the upper ocean, and in the formation of Antarctic Bottom Water, which can be traced far into the North Atlantic. To the extent that ice shelf attrition influences the flow of grounded ice, this work also has implications for ice sheet stability and sea level rise. | None | None | false | false |