USAP-DC

{"dp_type": "Dataset", "free_text": "Abrupt Climate Change"}

[{"awards": "1745078 Brook, Edward J.", "bounds_geometry": null, "date_created": "Tue, 23 Jul 2024 00:00:00 GMT", "description": "This dataset includes ~60-year resolution measurements of the Carbon-13 and Deuterium isotopic Composition of Atmospheric Methane (\u03b413C-CH4 and \u03b4D-CH4, respectively) of gas bubbles from the WAIS Divide Replicate Ice Core. All measurements were made at the University of Bern Ice Core Laboratory (Bern, Switzerland) using a new methane stable isotope analytical system. The data includes depth-adjacent replicate samples (separated by no more than 0.3m of depth). The data are displayed as a function of WAIS Divide Replicate Core depth and were corrected for gravitational and diffusional fractionation that occurs in the firn column according to Buizert et al., 2013. 1-sigma measurement uncertainty is also included and is determined from analytical uncertainty and uncertainties associated with diffusional and gravitational fractionation. Additional funding for this work was provided by the Swiss National Foundation, Awards #200020_172506 and #200020B_200328L.", "east": null, "geometry": null, "keywords": "Abrupt Climate Change; Antarctica; Atmospheric Gases; Biogeochemical Cycles; Carbon Cycle; Cryosphere; Greenhouse Gas; Methane; West Antarctic Ice Sheet Divide", "locations": "West Antarctic Ice Sheet Divide; Antarctica", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Riddell-Young, Benjamin; Lee, James; Schmitt, Jochen; Fischer, Hubertus; Bauska, Thomas; Menking, Andy; Iseli, Rene; Clark, Reid; Brook, Edward J.", "project_titles": "Tracing Past Methane Variations with Stable Isotopes in Antarctic Ice Cores", "projects": [{"proj_uid": "p0010416", "repository": "USAP-DC", "title": "Tracing Past Methane Variations with Stable Isotopes in Antarctic Ice Cores"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": null, "title": "Carbon-13 and Deuterium isotopic composition of atmospheric methane across Heinrich Stadial 4, and Dansgaard Oesgher Event 8, WAIS Divide Replicate Ice Core, Antarctica", "uid": "601813", "west": null}, {"awards": null, "bounds_geometry": null, "date_created": "Tue, 23 Jul 2024 00:00:00 GMT", "description": "This dataset includes measurements of the Deuterium isotopic Composition of Atmospheric Methane (\u03b4D-CH4) of gas bubbles from the Talos Dome Ice Core (TALDICE). All measurements were made at the University of Bern Ice Core Laboratory (Bern, Switzerland) using a new methane stable isotope analytical system. The data are displayed as a function of TALDICE depth and were corrected for gravitational and diffusional fractionation that occurs in the firn column according to Buizert et al., 2013. 1-sigma measurement uncertainty is also included and is determined from analytical uncertainty and uncertainties associated with diffusional and gravitational fractionation. Additional funding for this work was provided by the Swiss National Foundation: Award #200020_172506, and #200020B_200328L.", "east": null, "geometry": null, "keywords": "Abrupt Climate Change; Antarctica; Biogeochemical Cycles; Carbon Cycle; Cryosphere; Ice Core Records; Talos Dome", "locations": "Antarctica; Talos Dome", "north": null, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "persons": "Riddell-Young, Benjamin; Iseli, Rene; Lee, James; Schmitt, Jochen; Fischer, Hubertus; Bauska, Thomas; Menking, James; Clark, Reid; Brook, Edward J.", "project_titles": null, "projects": null, "repositories": null, "science_programs": null, "south": null, "title": "Deuterium isotopic composition of atmospheric methane across Dansgaard Oesgher Event 8, Talos Dome Ice Core, Antarctica", "uid": "601814", "west": null}, {"awards": "0944197 Waddington, Edwin", "bounds_geometry": ["POINT(-112.1115 -79.481)"], "date_created": "Tue, 28 Mar 2017 00:00:00 GMT", "description": "The West Antarctic Ice Sheet Divide (WAIS Divide, WD) ice core is a newly drilled, high-accumulation deep ice core that provides Antarctic climate records of the past ~68 ka at unprecedented temporal resolution. The upper 2850 m (back to 31.2 ka BP) have been dated using annual-layer counting. Here we present a chronology for the deep part of the core (67.8-31.2 ka BP), which is based on stratigraphic matching to annual-layer-counted Greenland ice cores using globally well-mixed atmospheric methane. We calculate the WD gas age-ice age difference (Delta age) using a combination of firn densification modeling, ice-flow modeling, and a data set of d15N-N2, a proxy for past firn column thickness. The largest Delta age at WD occurs during the Last Glacial Maximum, and is 525 +/- 120 years. Internally consistent solutions can be found only when assuming little to no influence of impurity content on densification rates, contrary to a recently proposed hypothesis. We synchronize the WD chronology to a linearly scaled version of the layer-counted Greenland Ice Core Chronology (GICC05), which brings the age of Dansgaard-Oeschger (DO) events into agreement with the U/Th absolutely dated Hulu Cave speleothem record. The small Delta age at WD provides valuable opportunities to investigate the timing of atmospheric greenhouse gas variations relative to Antarctic climate, as well as the interhemispheric phasing of the \\\"bipolar seesaw\\\".\n\nWe present the WD2014 chronology for the upper part (0-2850 m; 31.2 ka BP) of the West Antarctic Ice Sheet (WAIS) Divide (WD) ice core. The chronology is based on counting of annual layers observed in the chemical, dust and electrical conductivity records. These layers are caused by seasonal changes in the source, transport, and deposition of aerosols. The measurements were interpreted manually and with the aid of two automated methods. We validated the chronology by comparing to two high-accuracy, absolutely dated chronologies. For the Holocene, the cosmogenic isotope records of 10Be from WAIS Divide and 14C for IntCal13 demonstrated that WD2014 was consistently accurate to better than 0.5% of the age. For the glacial period, comparisons to the Hulu Cave chronology demonstrated that WD2014 had an accuracy of better than 1% of the age at three abrupt climate change events between 27 and 31ka. WD2014 has consistently younger ages than Greenland ice core chronologies during most of the Holocene. For the Younger Dryas-Preboreal transition (11.595 ka; 24 years younger) and the Bolling-Allerod Warming (14.621 ka; 7 years younger), WD2014 ages are within the combined uncertainties of the timescales. Given its high accuracy, WD2014 can become a reference chronology for the Southern Hemisphere, with synchronization to other chronologies feasible using high-quality proxies of volcanism, solar activity, atmospheric mineral dust, and atmospheric methane concentrations.", "east": -112.1115, "geometry": ["POINT(-112.1115 -79.481)"], "keywords": "Antarctica; Depth-Age-Model; Geochronology; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; WAIS Divide; WAIS Divide Ice Core", "locations": "WAIS Divide; Antarctica", "north": -79.481, "nsf_funding_programs": null, "persons": "Fudge, T. J.", "project_titles": "Collaborative Research: Establishing the Chronology and Histories of Accumulation and Ice Dynamics for the WAIS Divide Core", "projects": [{"proj_uid": "p0000026", "repository": "USAP-DC", "title": "Collaborative Research: Establishing the Chronology and Histories of Accumulation and Ice Dynamics for the WAIS Divide Core"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.481, "title": "WD2014: Timescale for WAIS Divide Core 2006 A (WDC-06A)", "uid": "601015", "west": -112.1115}, {"awards": "0944764 Brook, Edward J.", "bounds_geometry": ["POINT(-148.82 -81.66)"], "date_created": "Wed, 25 Jun 2014 00:00:00 GMT", "description": "This data set provides a new CO2 record from the Siple Dome ice core, Antarctica, that covers 7.4-9.0 ka (thousand years) with 8- to 16-year resolution. A small, about 1-2 ppm, increase of atmospheric CO2 during the 8.2 ka event was observed. The increase is not significant when compared to other centennial variations in the Holocene that are not linked to large temperature changes. The results do not agree with leaf stomata records that suggest a CO2 decrease of up to ~25 ppm and imply that the sensitivity of atmospheric CO2 to the primarily northern hemisphere cooling of the 8.2 ka event was limited.", "east": -148.82, "geometry": ["POINT(-148.82 -81.66)"], "keywords": "Antarctica; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Geochronology; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Paleoclimate; Siple Dome; Siple Dome Ice Core; South Pole; WAISCORES", "locations": "Antarctica; South Pole; Siple Dome", "north": -81.66, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Brook, Edward J.; Ahn, Jinho", "project_titles": "Atmospheric CO2 and Abrupt Climate Change", "projects": [{"proj_uid": "p0000179", "repository": "USAP-DC", "title": "Atmospheric CO2 and Abrupt Climate Change"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": -81.66, "title": "High-resolution Atmospheric CO2 during 7.4-9.0 ka", "uid": "609527", "west": -148.82}, {"awards": "0944764 Brook, Edward J.", "bounds_geometry": ["POINT(-119.83 -80.01)", "POINT(-148.82 -81.66)"], "date_created": "Thu, 08 Aug 2013 00:00:00 GMT", "description": "During the last glacial period atmospheric carbon dioxide and temperature in Antarctica varied in a similar fashion on millennial time scales, but previous work indicates that these changes were gradual. In a detailed analysis of one event, we now find that approximately half of the CO2 increase that occurred during the 1500 year cold period between Dansgaard-Oeschger (DO) Events 8 and 9 happened rapidly, over less than two centuries. This rise in CO2 was synchronous with, or slightly later than, a rapid increase of Antarctic temperature inferred from stable isotopes.", "east": -119.83, "geometry": ["POINT(-119.83 -80.01)", "POINT(-148.82 -81.66)"], "keywords": "Antarctica; Arctic; Byrd; Chemistry:fluid; Chemistry:Fluid; CO2; Geochemistry; GISP2; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Methane; Paleoclimate; Siple Dome Ice Core; Taylor Dome; Taylor Dome Ice Core", "locations": "Antarctica; Arctic; Taylor Dome", "north": -80.01, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Brook, Edward J.; Ahn, Jinho", "project_titles": "Atmospheric CO2 and Abrupt Climate Change", "projects": [{"proj_uid": "p0000179", "repository": "USAP-DC", "title": "Atmospheric CO2 and Abrupt Climate Change"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core; Taylor Dome Ice Core; Byrd Ice Core", "south": -81.66, "title": "Abrupt Change in Atmospheric CO2 During the Last Ice Age", "uid": "609539", "west": -148.82}, {"awards": "0337891 Brook, Edward J.", "bounds_geometry": ["POINT(158 -77.666667)"], "date_created": "Mon, 05 Nov 2007 00:00:00 GMT", "description": "Using new and existing ice core CO2 data from 65 - 30 ka BP a new chronology for Taylor Dome ice core CO2 is established and synchronized with Greenland ice core records to study how high latitude climate change and the carbon cycle were linked during the last glacial period. The new data and chronology should provide a better target for models attempting to explain CO2 variability and abrupt climate change.", "east": 158.0, "geometry": ["POINT(158 -77.666667)"], "keywords": "Antarctica; Atmosphere; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Paleoclimate; Taylor Dome; Taylor Dome Ice Core", "locations": "Taylor Dome; Antarctica", "north": -77.666667, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Brook, Edward J.; Ahn, Jinho", "project_titles": "Developing Dry Extraction of Ice Core Gases and Application to Millennial-Scale Variability in Atmospheric CO2", "projects": [{"proj_uid": "p0000268", "repository": "USAP-DC", "title": "Developing Dry Extraction of Ice Core Gases and Application to Millennial-Scale Variability in Atmospheric CO2"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Taylor Dome Ice Core", "south": -77.666667, "title": "Atmospheric CO2 and Climate: Taylor Dome Ice Core, Antarctica", "uid": "609315", "west": 158.0}, {"awards": "0337891 Brook, Edward J.", "bounds_geometry": ["POINT(-119.833611 -80.01)"], "date_created": "Fri, 26 Oct 2007 00:00:00 GMT", "description": "Reconstructions of ancient atmospheric CO2 variations help us better understand how the global carbon cycle and climate are linked. This data set compares CO2 variations on millennial time scales between 20,000 and 90,000 years with an Antarctic temperature proxy and records of abrupt climate change in the Northern hemisphere.", "east": -119.833611, "geometry": ["POINT(-119.833611 -80.01)"], "keywords": "Antarctica; Atmosphere; Byrd Glacier; Byrd Ice Core; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Paleoclimate", "locations": "Byrd Glacier; Antarctica", "north": -80.01, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Brook, Edward J.; Ahn, Jinho", "project_titles": "Developing Dry Extraction of Ice Core Gases and Application to Millennial-Scale Variability in Atmospheric CO2", "projects": [{"proj_uid": "p0000268", "repository": "USAP-DC", "title": "Developing Dry Extraction of Ice Core Gases and Application to Millennial-Scale Variability in Atmospheric CO2"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Byrd Ice Core", "south": -80.01, "title": "Atmospheric CO2 and Climate: Byrd Ice Core, Antarctica", "uid": "609314", "west": -119.833611}]

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