Sulfate in air and snow at the South Pole: Implications for transport and deposition at sites with low snow accumulation
Article first published online: 21 SEP 2012
Copyright 2000 by the American Geophysical Union.
Journal of Geophysical Research: Atmospheres (1984–2012)
Volume 105, Issue D18, pages 22825–22832, 27 September 2000
How to Cite
2000), Sulfate in air and snow at the South Pole: Implications for transport and deposition at sites with low snow accumulation, J. Geophys. Res., 105(D18), 22825–22832, doi:10.1029/2000JD900351., , and (
- Issue published online: 21 SEP 2012
- Article first published online: 21 SEP 2012
- Manuscript Accepted: 2 JUN 2000
- Manuscript Received: 6 MAR 2000
Air and surface snow were sampled at Amundsen-Scott Station at the South Pole from July through December of 1992. Four-day averages of non-sea-salt sulfate (nss-SO4=) aerosol show a strong seasonal trend, increasing by a factor of about 30 from winter to summer as oceanic biogenic sources become more active and atmospheric transport pathways change. Three-dimensional sampling of small-scale surface topography (sastrugi) provides evidence supporting wind pumping and filtration of aerosol by snow as a significant mechanism for dry deposition at this site. The estimated monthly flux of nss-SO4= to the snow surface also increases from winter to spring, but by only a factor of 2, suggesting that the efficiency of deposition for this aerosol-borne species from the near-surface air to the snow is greater in winter. The strong surface-based temperature inversion in winter inhibits vertical motion and may limit the rate of delivery of aerosol to the boundary layer from the free troposphere. Because the snow surface is a sink for aerosol, near-surface measurements of aerosol in the stable inversion layer may not be representative of the free troposphere. Air and snow data in summer (when the inversion is weak) are used to estimate a tropospheric residence time of 4–20 days for nss SO4=.