An overview of ISCAT 2000

Authors

D D. Davis, Georgia Institute of Technology
Fred Eisele, NCAR
G Chen, Georgia Institute of Technology - Main CampusFollow
J Crawford, NASA - Langley Research CenterFollow
L Gregory Huey, Georgia Institute of Technology - Main Campus
D Tanner, Georgia Institute of Technology - Main Campus
D Slusher, Georgia Institute of Technology - Main Campus
Lee Mauldin, NCAR
S Oncley, NCAR
D Lenschow, NCAR
S Semmer, NCAR
R E. Shetter, NOAA
Barry Lefer, University of Houston - Main
Richard Arimoto, New Mexico State University - Carlsbad
A Hogan, Desert Research Inst.
P Grube, Lyndon State College
M Lazzara, University of Wisconsin-Madison
A R. Bandy, Drexel University
D C. Thornton, Drexel University
H Berresheim, German Weather Service
H Bingemer, Frankfurt University
Manuel Hutterli, University of Arizona
J R. McConnell, Desert Research Institute
R Bales, University of Arizona
Jack E. Dibb, University of New HampshireFollow
Martin Buhr, Air Quality Design, Inc.
J Park, University of Minnesota - Twin Cities
P McMurry, University of Minnesota - Twin Cities
Aaron L. Swanson, University of California, Irvine
Simone Meinardi, University of California, Davis
D R. Blake, University of California, Irvine

Abstract

The Investigation of Sulfur Chemistry in the Antarctic Troposphere (ISCAT) took place over the timer period of 15 November to 31 December in the year 2000. The study location was the Amundsen Scott Station in Antarctica. ISCAT 2000 defines the second phase of a program designed to explore tropospheric chemistry in Antarctica. As in 1998, the 2000 ISCAT study revealed a strong oxidizing environment at South Pole (SP). During the 2000 investigation, however, the suite of measurements was greatly expanded. These new measurements established the recycling of reactive nitrogen as a critical component of this unique environment. This paper first presents the historical background leading up to the ISCAT 2000 observations; then it focuses on providing a summary of the year 2000 results and contrasts these with those recorded during 1998. Important developments made during the 2000 study included the recording of SP data for several species being emitted from the snowpack. These included NO, H₂O₂ and CH₂O. In this context, eddy-diffusion flux measurements provided the first quantitative estimates of the SP NO and NO_x snow-to-atmosphere fluxes. This study also revealed that HNO₃ and HO₂NO₂ were major sink species for HO_x and NO_x radicals. And, it identified the critical factors responsible for SP NO levels exceeding those at other polar sites by nearly an order of magnitude. Finally, it reports on the levels of gas phase sulfur species and provides evidence indicating that the absence of DMS at SP is most likely due to its greatly shorten chemical lifetime in the near vicinity of the plateau. It is proposed that this is due to the influence of NO on the distribution of OH in the lower free troposphere over a region that extends well beyond the plateau itself. Details related to each of the above findings plus others can be found in the 11 accompanying Special Issue papers.

Department

Earth Sciences, Earth Systems Research Center

Publication Date

10-2004

Journal Title

Atmospheric Environment

Publisher

Elsevier

Digital Object Identifier (DOI)

10.1016/j.atmosenv.2004.05.037

Document Type

Article

Recommended Citation

D.D. Davis, F. Eisele, G. Chen, J. Crawford, G. Huey, D. Tanner, D. Slusher, L. Mauldin, S. Oncley, D. Lenschow, S. Semmer, R. Shetter, B. Lefer, R. Arimoto, A. Hogan, P. Grube, M. Lazzara, A. Bandy, D. Thornton, H. Berresheim, H. Bingemer, M. Hutterli, J. McConnell, R. Bales, J. Dibb, M. Buhr, J. Park, P. McMurry, A. Swanson, S. Meinardi, D. Blake, An overview of ISCAT 2000, Atmospheric Environment, Volume 38, Issue 32, October 2004, Pages 5363-5373, ISSN 1352-2310, http://dx.doi.org/10.1016/j.atmosenv.2004.05.037.

Rights

Copyright © 2004 Elsevier Ltd. All rights reserved.