A reassessment of HOx South Pole chemistry based on observations recorded during ISCAT 2000

Authors

G Chen, Georgia Institute of Technology - Main CampusFollow
D D. Davis, Georgia Institute of Technology
J Crawford, NASA - Langley Research CenterFollow
Manuel Hutterli, University of Arizona
L Gregory Huey, Georgia Institute of Technology - Main Campus
D Slusher, Georgia Institute of Technology - Main Campus
Lee Mauldin, NCAR
Fred Eisele, NCAR
D Tanner, Georgia Institute of Technology - Main Campus
Jack E. Dibb, University of New HampshireFollow
Martin Buhr, Georgia Institute of Technology - Main Campus
J R. McConnell, Desert Research Institute
Barry Lefer, University of Houston - Main
R E. Shetter, NOAA
D R. Blake, University of California, Irvine
C H. Song
K Lombardi, Georgia Institute of Technology - Main Campus
J Arnoldy, Georgia Institute of Technology - Main Campus

Abstract

Reported here are modeling results based on ISCAT (Investigation of Sulfur Chemistry of Antarctic Troposphere) 2000 observations recorded at the South Pole (SP) during the Austral Summer of 2000. The observations included a comprehensive set of photochemical parameters, e.g., NO, O3, and CO. It is worthy to note that not only were OH and HO2 observed, but also HOx precursor species CH2O, H2O2, and HONO were measured. Previous studies have suggested that HONO is the major source of OH/HOx in the Arctic; however, observed HONO levels at SPinduced dramatic model overprediction of both HOx and NOx when used to constrain the model calculations. In contrast, model predictions constrained by observed values of CH2O and H2O2 are consistent with the observations of OH and HO2 (i.e., within 20%) for more than half of the data. Significant model overpredictions of OH, however, were seen at the NO levels lower than 50 pptv or higher than 150 pptv. An analysis of HOx budget at the median NO level suggests that snow emissions of H2O2 and CH2O are the single most important primary source of SPHOx, contributing 46% to the total source. Major sinks for HOx are found to be dry deposition of HO2NO2 and HNO3 as well as their reactions with OH. Although ISCAT 2000 led to a major progress in our understanding of SPHOx chemistry, critical aspects of this chemistry are still in need of further investigation.

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.2003.07.018

Document Type

Article

Recommended Citation

G. Chen, D. Davis, J. Crawford, L.M. Hutterli, L.G. Huey, D. Slusher, L. Mauldin, F. Eisele, D. Tanner, J. Dibb, M. Buhr, J. McConnell, B. Lefer, R. Shetter, D. Blake, C.H. Song, K. Lombardi, J. Arnoldy, A reassessment of HOx South Pole chemistry based on observations recorded during ISCAT 2000, Atmospheric Environment, Volume 38, Issue 32, October 2004, Pages 5451-5461, ISSN 1352-2310, http://dx.doi.org/10.1016/j.atmosenv.2003.07.018.

Rights

r 2004 Elsevier Ltd. All rights reserved.