Spatial variability of perchlorate in East Antarctic surface snow: Implications for atmospheric production. (1st October 2020)

• Record Type: Journal Article
• Authors: Jiang, Su; Cole-Dai, Jihong; An, Chunlei; Shi, Guitao; Yu, Jinhai; Sun, Bo
• Is Part Of: Atmospheric environment. Volume 238(2020)
• Publication Date: 2020-10-01
• Subjects: Perchlorate -- Atmospheric production -- Stratosphere -- Troposphere -- Spatial variability -- Antarctic snow; Air -- Pollution -- Periodicals; Air -- Pollution -- Meteorological aspects -- Periodicals; 551.51
• DOI: 10.1016/j.atmosenv.2020.117743
• Languages: English
• ISSNs: 1352-2310

Abstract

Abstract: Surface snow along a 1250-km transect from the coast to the East Antarctic ice sheet summit Dome Argus are used to investigate factors influencing spatial variability of perchlorate (ClO4 − ) production and deposition, and to explore contributions from tropospheric and stratospheric sources to ClO4 − in Antarctic snow. The average ClO4 − concentration of 104.3 ± 33.3 ng kg −1 is in the range of previously reported ClO4 − concentrations in Antarctic snow, and one to two orders of magnitude higher than those in Arctic snow. The transect profile of ClO4 − concentration shows relatively small spatial variability and no single consistent trend, with apparently high concentrations at locations with low accumulation rate. In the coastal region, strong correlation between ClO4 − and troposphere-produced nitrate (NO3 − ) is observed. This may indicate that ClO4 − in the coastal region is formed predominantly in the troposphere during summer, and the contribution from the stratosphere may be negligibly small. The lack of apparent correlation between ClO4 − and NO3 − in snow in interior East Antarctica suggests that a significant amount of ClO4 − may be of stratospheric origin, with some tropospheric production. No significant correlation is found between sea-salt chloride (Cl − ) and ClO4 − in the coastal region, suggesting that tropospheric sea-salt Cl − is probably not an important precursor of ClO4 − in snow in this region. In the inland Dome A region, part of Cl − might be converted into ClO4 − . Highlights: (3–5 bullets, <85 characters including spaces): Concentration of ClO4 − shows relatively small spatial variability along the transect. Perchlorate may be formed mainly in the troposphere in the coastal region in summer. Perchlorate may be of stratospheric and tropospheric origin in inland East Antarctica. Sea-salt Cl − is probably not an important precursor of ClO4 − in the coastal region.