TY  - JOUR
AU  - Legrand M, Preunkert S.
PY  - 2014//
TI  - Large mixing ratios of atmospheric nitrous acid (HONO) at Concordia (East Antarctic Plateau) in summer: a strong source from surface snow?
T2  - 1680-7316
JO  - Atmospheric Chemistry and Physics
SP  - 9963
EP  - 9976
VL  - 14
IS  - 18
PB  - Copernicus GmbH
N2  - During the austral summer 2011/2012 atmospheric nitrous acid (HONO) was investigated for the secondtime at the Concordia site (75060 S, 123330 E), located on the East Antarctic Plateau, by deploying a long-path absorption photometer (LOPAP). Hourly mixing ratios of HONO measured in December 2011/January 2012 (35±5.0 pptv) were similar to those measured in December 2010/January2011 (30.4±3.5 pptv). The large value of the HONO mixing ratio at the remote Concordia site suggests a local source of HONO in addition to weak production from oxidation ofNO by the OH radical. Laboratory experiments demonstrate that surface snow removed from Concordia can produce gasphase HONO at mixing ratios half that of the NOx mixing ratio produced in the same experiment at typical temperatures encountered at Concordia in summer. Using these lab data and the emission flux of NOx from snow estimated from the vertical gradient of atmospheric concentrations measured during the campaign, a mean diurnal HONO snow emission ranging between 0.5 and 0.8×109 molecules cm-2 s-1 is calculated. Model calculations indicate that, in addition to around 1.2 pptv of HONO produced by the NO oxidation, these HONO snow emissions can only explain 6.5 to 10.5 pptv of HONO in the atmosphere at Concordia. To explain the difference between observed and simulated HONO mixing ratios, tests were done both in the field and at lab to explore the possibility that the presence of HNO4 had biased the measurements of HONO.
SN  - 1680-7316
UR  - http://dx.doi.org/10.5194/acp-14-9963-2014
N1  - exported from refbase (http://publi.ipev.fr/polar_references/show.php?record=5968), last updated on Wed, 03 Jul 2024 19:20:59 +0200
ID  - LegrandM2014
ER  -