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The overall objective of this research is to (1) develop high resolution measurements of a range of aerosol-related elements, chemical species, and isotopes in archived Greenland Ice Sheet Project Two (GISP2) ice corresponding to Greenland stadial and interstadial events 5 through 12 from the last Glacial period, and (2) use these measurements -- together with the Goddard Earth Observing System (GEOS)-Chem atmospheric chemistry and other models -- to better understand climate processes and feedbacks underlying rapid climate change events and atmospheric chemistry during the last Glacial with particular focus on biomass burning emissions. Here we report high resolution (approximately annual) and decadal-scale measurements of water stable isotopic ratios, refractory black carbon concentration and particle size, semi-quantitative insoluble particle mass concentration, as well as ammonium, sea-salt sodium and non-sea-salt calcium concentrations measured from 2100 to 2365 meter (m) depth in the GISP2 core. These data ,as well as a modified simple atmospheric transport model, were used initially to evaluate aerosol emissions, transport, and deposition during rapid climate change events GI 5 through GI 12 (Liu et al., 2024).
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Carbonyl sulfide measurements from a South Pole ice core and implications for atmospheric variability since the last glacial period
Abstract. Carbonyl sulfide (COS) is the most abundant sulfur gas in the atmosphere with links to terrestrial and oceanic productivity. We measured COS in ice core air from an intermediate-depth ice core from the South Pole using both dry and wet extraction methods, recovering a 52 500-year record. We find evidence for COS production in the firn, altering the atmospheric signal preserved in the ice core. Mean sea salt aerosol concentrations from the same depth are a good proxy for the COS production, which disproportionately impacts the measurements from glacial period ice with high sea salt aerosol concentrations. The COS measurements are corrected using sea salt sodium (ssNa) as a proxy for the excess COS resulting from the production. The ssNa-corrected COS record displays substantially less COS in the glacial period atmosphere than the Holocene and a 2 to 4-fold COS rise during the deglaciation synchronous with the associated climate signal. The deglacial COS rise was primarily source driven. Oceanic emissions in the form of COS, carbon disulfide (CS2), and dimethylsulfide (DMS) are collectively the largest natural source of atmospheric COS. A large increase in ocean COS emissions during the deglaciation suggests enhancements in emissions of ocean sulfur gases via processes that involve ocean productivity, although we cannot quantify individual contributions from each gas.
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- PAR ID:
- 10608398
- Publisher / Repository:
- Copernicus
- Date Published:
- Journal Name:
- Climate of the Past
- Volume:
- 20
- Issue:
- 8
- ISSN:
- 1814-9332
- Page Range / eLocation ID:
- 1885 to 1917
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.5194/cp-20-1885-2024
