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Measurements of pernitric acid at the South Pole during ISCAT 2000
Author(s) -
Slusher D. L.,
Huey L. G.,
Tanner D. J.,
Chen G.,
Davis D. D.,
Buhr M.,
Nowak J. B.,
Eisele F. L.,
Kosciuch E.,
Mauldin R. L.,
Lefer B. L.,
Shetter R. E.,
Dibb J. E.
Publication year - 2002
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2002gl015703
Subject(s) - snow , snowpack , troposphere , sink (geography) , acid deposition , atmospheric sciences , nitrate , decomposition , environmental science , polar , atmospheric chemistry , photodissociation , sulfur , deposition (geology) , environmental chemistry , chemistry , climatology , meteorology , photochemistry , geology , ozone , physics , soil science , soil water , geomorphology , cartography , organic chemistry , astronomy , sediment , geography
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 HO 2 NO 2 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 NO x and HO x . Another is that the photochemistry of HO 2 NO 2 in the Antarctic snowpack may be a NO x 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.