Measurements of pernitric acid at the South Pole during ISCAT 2000
Article first published online: 2 NOV 2002
Copyright 2002 by the American Geophysical Union.
Geophysical Research Letters
Volume 29, Issue 21, pages 7-1–7-4, November 2002
How to Cite
Measurements of pernitric acid at the South Pole during ISCAT 2000, Geophys. Res. Lett., 29(21), 2011, doi:10.1029/2002GL015703, 2002., , , , , , , , , , , , and ,
- Issue published online: 2 NOV 2002
- Article first published online: 2 NOV 2002
- Manuscript Revised: 13 SEP 2002
- Manuscript Accepted: 13 SEP 2002
- Manuscript Received: 19 JUN 2002
 The first measurements of pernitric acid at the South Pole were performed during the second Investigation of Sulfur Chemistry in the Antarctic Troposphere (ISCAT 2000). Observed HO2NO2 concentrations averaged 25 pptv. Simple steady-state calculations constrained by measurements show that the lifetime of pernitric acid was largely controlled by dry deposition, with thermal decomposition becoming increasingly important at warmer temperatures. We determined that the pernitric acid equilibrium constant is less uncertain than indicated in the literature. One consequence of pernitric acid deposition to the snow surface is that it is an important sink for both NOx and HOx. Another is that the photochemistry of HO2NO2 in the Antarctic snowpack may be a NOx source in addition to nitrate photolysis. This might be one of the important differences in snow photochemistry between the South Pole and warmer polar sites.