USAP-DC

{"dp_type": "Dataset", "free_text": "Model Results"}

[{"awards": "1744835 Wagner, Till", "bounds_geometry": ["POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))"], "date_created": "Tue, 18 Jan 2022 00:00:00 GMT", "description": "Because of difficulties in adequately simulating their breakup, large Antarctic icebergs to date have either not been represented in models or represented but with no breakup scheme such that they consistently survive too long and travel too far compared with observations. Here, we introduce a representation of iceberg fracturing using a breakup scheme based on the \u201cfootloose mechanism.\u201d We optimize the parameters of this breakup scheme by forcing the iceberg model with an ocean state estimate and comparing the modeled iceberg trajectories and areas with the Antarctic Iceberg Tracking Database. We show that including large icebergs and a representation of their breakup substantially affects the iceberg meltwater distribution, with implications for the circulation and stratification of the Southern Ocean.\r\n\r\nThis data link includes the model developed for the study, including a link to the forcing fields needed to replicate the model results. ", "east": 180.0, "geometry": ["POINT(0 -89.999)"], "keywords": "Antarctica; Footloose Mechanism; Iceberg Breakup; Iceberg Decay; Model; Southern Ocean", "locations": "Southern Ocean; Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences; Antarctic Ocean and Atmospheric Sciences", "persons": "Wagner, Till", "project_titles": "Modeling Giant Icebergs and Their Decay", "projects": [{"proj_uid": "p0010290", "repository": "USAP-DC", "title": "Modeling Giant Icebergs and Their Decay"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Model of iceberg drift and decay including breakup", "uid": "601510", "west": -180.0}, {"awards": "1043485 Curtice, Josh", "bounds_geometry": ["POLYGON((163.4 -77.47989,163.9848 -77.47989,164.5696 -77.47989,165.1544 -77.47989,165.7392 -77.47989,166.324 -77.47989,166.9088 -77.47989,167.4936 -77.47989,168.0784 -77.47989,168.6632 -77.47989,169.248 -77.47989,169.248 -77.565701,169.248 -77.651512,169.248 -77.737323,169.248 -77.823134,169.248 -77.908945,169.248 -77.994756,169.248 -78.080567,169.248 -78.166378,169.248 -78.252189,169.248 -78.338,168.6632 -78.338,168.0784 -78.338,167.4936 -78.338,166.9088 -78.338,166.324 -78.338,165.7392 -78.338,165.1544 -78.338,164.5696 -78.338,163.9848 -78.338,163.4 -78.338,163.4 -78.252189,163.4 -78.166378,163.4 -78.080567,163.4 -77.994756,163.4 -77.908945,163.4 -77.823134,163.4 -77.737323,163.4 -77.651512,163.4 -77.565701,163.4 -77.47989))"], "date_created": "Thu, 01 Jan 2015 00:00:00 GMT", "description": "This award supports a project to develop a better understanding of the response of the WAIS to climate change. The timing of the last deglaciation of the western Ross Sea will be improved using in situ terrestrial cosmogenic nuclides (3He, 10Be, 14C, 26Al, 36Cl) to date glacial erratics at key areas and elevations along the western Ross Sea coast. A state-of-the art ice sheet-shelf model will be used to identify mechanisms of deglaciation of the Ross Sea sector of WAIS. The model results and forcing will be compared with observations including the new cosmogenic data proposed here, with the aim of better determining and understanding the history and causes of WAIS deglaciation in the Ross Sea. There is considerable uncertainty, however, in the history of grounding line retreat from its last glacial maximum position, and virtually nothing is known about the timing of ice- surface lowering prior to ~10,000 years ago. Given these uncertainties, we are currently unable to assess one of the most important questions regarding the last deglaciation of the global ice sheets, namely as to whether the Ross Sea sector of WAIS contributed significantly to meltwater pulse 1A (MWP-1A), an extraordinarily rapid (~500-year duration) episode of ~20 m sea-level rise that occurred ~14,500 years ago. The intellectual merit of this project is that recent observations of startling changes at the margins of the Greenland and Antarctic ice sheets indicate that dynamic responses to warming may play a much greater role in the future mass balance of ice sheets than considered in current numerical projections of sea level rise. The broader impacts of this work are that it has direct societal relevance to developing an improved understanding of the response of the West Antarctic ice sheet to current and possible future environmental changes including the sea-level response to glacier and ice sheet melting due to global warming. The PI will communicate results from this project to a variety of audiences through the publication of peer-reviewed papers and by giving talks to public audiences. Finally the project will support a graduate student and undergraduate students in all phases of field-work, laboratory work and data interpretation.\n", "east": 169.248, "geometry": ["POINT(166.324 -77.908945)"], "keywords": "Antarctica; Cosmogenic Dating; Ross Sea; Sample/collection Description; Sample/Collection Description; Southern Ocean; WAIS", "locations": "Ross Sea; WAIS; Antarctica; Southern Ocean", "north": -77.47989, "nsf_funding_programs": null, "persons": "Kurz, Mark D.; Curtice, Josh", "project_titles": "Collaborative Research: A New Reconstruction of the Last West Antarctic Ice Sheet Deglaciation in the Ross Sea", "projects": [{"proj_uid": "p0000194", "repository": "USAP-DC", "title": "Collaborative Research: A New Reconstruction of the Last West Antarctic Ice Sheet Deglaciation in the Ross Sea"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.338, "title": "A New Reconstruction of the Last West Antarctic Ice Sheet Deglaciation in the Ross Sea", "uid": "600123", "west": 163.4}, {"awards": "0944584 Sowers, Todd; 0538538 Sowers, Todd; 0538578 Brook, Edward J.", "bounds_geometry": ["POINT(-112.0865 -79.4676)", "POINT(-38.5 72.6)"], "date_created": "Fri, 31 Jan 2014 00:00:00 GMT", "description": "This data set measures methane concentrations in ancient air trapped in the West Antarctic Ice Sheet (WAIS) Divide and Greenland Ice Sheet Project (GISP2) ice cores; presenting two, high-resolution ice core methane records of the past 2500 years, one from each pole. These measurements were used to reconstruct the methane Inter-Polar Difference (IPD) during the late Holocene. Also included are model results of methane emissions that were presented in the manuscript describing this data set.", "east": -38.5, "geometry": ["POINT(-112.0865 -79.4676)", "POINT(-38.5 72.6)"], "keywords": "Antarctica; Arctic; Chemistry:fluid; Chemistry:Fluid; Geochemistry; GISP2; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Methane; Paleoclimate; WAIS Divide; WAIS Divide Ice Core", "locations": "Arctic; WAIS Divide; Antarctica", "north": 72.6, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Mitchell, Logan E", "project_titles": "Collaborative Research: Constructing an Ultra-high Resolution Atmospheric Methane Record for the Last 140,000 Years from WAIS Divide Core.", "projects": [{"proj_uid": "p0000025", "repository": "USAP-DC", "title": "Collaborative Research: Constructing an Ultra-high Resolution Atmospheric Methane Record for the Last 140,000 Years from WAIS Divide Core."}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.4676, "title": "Late Holocene Methane Concentrations from WAIS Divide and GISP2", "uid": "609586", "west": -112.0865}, {"awards": "1354231 Kowalewski, Douglas", "bounds_geometry": ["POLYGON((-160 -70,-156 -70,-152 -70,-148 -70,-144 -70,-140 -70,-136 -70,-132 -70,-128 -70,-124 -70,-120 -70,-120 -71.5,-120 -73,-120 -74.5,-120 -76,-120 -77.5,-120 -79,-120 -80.5,-120 -82,-120 -83.5,-120 -85,-124 -85,-128 -85,-132 -85,-136 -85,-140 -85,-144 -85,-148 -85,-152 -85,-156 -85,-160 -85,-160 -83.5,-160 -82,-160 -80.5,-160 -79,-160 -77.5,-160 -76,-160 -74.5,-160 -73,-160 -71.5,-160 -70))"], "date_created": "Wed, 01 Jan 2014 00:00:00 GMT", "description": "Intellectual Merit: Neogene sediment records recovered by ANDRILL suggest multiple events of open water conditions and elevated sea surface temperatures at times when terrestrial data from the McMurdo Dry Valleys indicate hyper arid, cold, desert conditions. Interpretation of the ANDRILL data suggests the West Antarctic Ice Sheet is highly sensitive to changes in Pliocene sea surface temperatures and this conclusion has been supported by recent Global Circulation Model results for the early to mid Pliocene. The PIs propose to model paleo-ice configurations and warm orbits associated with a WAIS collapse to assess potential climate change in East Antarctica. During such episodes of polar warmth they propose to answer: What is the limit of ablation along the East Antarctic Ice Sheet?; Are relict landforms in the Dry Valleys susceptible to modification from increase in maximum summertime temperatures?; and Is there sufficient increase in minimum wintertime temperatures to sustain a tundra environment in the Dry Valleys? Integration of depositional records and model outputs have the potential to test the performance of numerical models currently under development as part of ANDRILL; reconcile inconsistencies between marine and terrestrial paleoclimate records in high Southern Latitudes; and improve understanding of Antarctic climate and ice volume sensitivity to forcing for both the East Antarctic and West Antarctic Ice Sheets. Broader impacts: Results from this study have the potential to be used widely by the research community. Outreach to local elementary schools from other funded efforts will continue and be extended to homeschooled students. A Post Doc will be supported as part of this award.\n", "east": -120.0, "geometry": ["POINT(-140 -77.5)"], "keywords": "Antarctica; Atmosphere; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Model Data; Paleoclimate; Transantarctic Mountains", "locations": "Antarctica; Transantarctic Mountains", "north": -70.0, "nsf_funding_programs": null, "persons": "Kowalewski, Douglas", "project_titles": "Validating contrasting terrestrial climate-sensitive Pliocene deposits through high resolution modeling of paleo-environments in the Transantarctic Mountains", "projects": [{"proj_uid": "p0000463", "repository": "USAP-DC", "title": "Validating contrasting terrestrial climate-sensitive Pliocene deposits through high resolution modeling of paleo-environments in the Transantarctic Mountains"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -85.0, "title": "Validating contrasting terrestrial climate-sensitive Pliocene deposits through high resolution modeling of paleo-environments in the Transantarctic Mountains", "uid": "600140", "west": -160.0}, {"awards": "0440666 Waddington, Edwin", "bounds_geometry": ["POINT(158.716667 -77.783333)", "POINT(-111.816667 -79.416667)"], "date_created": "Sun, 20 Jun 2010 00:00:00 GMT", "description": "This data set contains radar internal layer and ice sheet topography data for two sites in Antarctica, along with associated model results from two studies. This project used geophysical inverse theory and a 2.5 D flowband ice-flow forward model to extract robust transient accumulation patterns from multiple deeper layers. Histories of divide migration, or the movement of the ice sheet and ice-surface evolution are also provided. The data used to solve the inverse problem, and the model solutions are provided. Internal layers, modern ice-surface velocities, and modern ice-sheet geometry at Taylor Mouth are available, as well as the pattern of accumulation inferred by Waddington et al. (2007).\n\nData are available via FTP in Matlab (.mat) format. Supporting information is available as text files (.rtf and .txt).", "east": 158.716667, "geometry": ["POINT(158.716667 -77.783333)", "POINT(-111.816667 -79.416667)"], "keywords": "Antarctica; Elevation; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; WAIS Divide; WAIS Divide Ice Core", "locations": "WAIS Divide; Antarctica", "north": -77.783333, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Waddington, Edwin D.; Koutnik, Michelle", "project_titles": "Histories of accumulation, thickness and WAIS Divide location from radar layers using a new inverse approach", "projects": [{"proj_uid": "p0000018", "repository": "USAP-DC", "title": "Histories of accumulation, thickness and WAIS Divide location from radar layers using a new inverse approach"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.416667, "title": "Histories of Accumulation, Thickness, and WAIS Divide Location, Antarctica", "uid": "609473", "west": -111.816667}]

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