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Regional Characteristics of Atmospheric Sulfate Formation in East Antarctica Imprinted on 17 O‐Excess Signature
- Source :
- Journal of Geophysical Research: Atmospheres, Journal of Geophysical Research: Atmospheres, American Geophysical Union, 2021, 126 (6), pp.e2020JD033583. ⟨10.1029/2020JD033583⟩, Journal of Geophysical Research: Atmospheres, 2021, 126 (6), pp.e2020JD033583. ⟨10.1029/2020JD033583⟩
- Publication Year :
- 2021
- Publisher :
- AMER GEOPHYSICAL UNION, 2021.
-
Abstract
- International audience; 17O-excess (Δ17O = δ17O − 0.52 × δ18O) of sulfate trapped in Antarctic ice cores has been proposed as a potential tool for assessing past oxidant chemistry, while insufficient understanding of atmospheric sulfate formation around Antarctica hampers its interpretation. To probe influences of regional specific chemistry, we compared year-round observations of Δ17O of non-sea-salt sulfate in aerosols (Δ17O(SO42−)nss) at Dome C and Dumont d'Urville, inland and coastal sites in East Antarctica, throughout the year 2011. Although Δ17O(SO42−)nss at both sites showed consistent seasonality with summer minima (∼1.0‰) and winter maxima (∼2.5‰) owing to sunlight-driven changes in the relative importance of O3 oxidation to OH and H2O2 oxidation, significant intersite differences were observed in austral spring–summer and autumn. The cooccurrence of higher Δ17O(SO42−)nss at inland (2.0‰ ± 0.1‰) than the coastal site (1.2‰ ± 0.1‰) and chemical destruction of methanesulfonate (MS–) in aerosols at inland during spring–summer (October–December), combined with the first estimated Δ17O(MS–) of ∼16‰, implies that MS– destruction produces sulfate with high Δ17O(SO42−)nss of ∼12‰. If contributing to the known postdepositional decrease of MS– in snow, this process should also cause a significant postdepositional increase in Δ17O(SO42−)nss over 1‰, that can reconcile the discrepancy between Δ17O(SO42−)nss in the atmosphere and ice. The higher Δ17O(SO42−)nss at the coastal site than inland during autumn (March–May) may be associated with oxidation process involving reactive bromine and/or sea-salt particles around the coastal region.
- Subjects :
- [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere
Atmospheric Science
010504 meteorology & atmospheric sciences
methanesulfonate
Geochemistry
East antarctica
sulfate
010501 environmental sciences
01 natural sciences
chemistry.chemical_compound
Geophysics
chemistry
13. Climate action
Space and Planetary Science
[SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry
Earth and Planetary Sciences (miscellaneous)
Environmental science
Antarctica
[SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology
Sulfate
Signature (topology)
isotope
aerosols
0105 earth and related environmental sciences
Subjects
Details
- Language :
- English
- ISSN :
- 2169897X and 21698996
- Volume :
- 126
- Issue :
- 6
- Database :
- OpenAIRE
- Journal :
- JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES = JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
- Accession number :
- edsair.doi.dedup.....b447f9f140fb000356e774ab23f0b10d