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| Titel |
Formaldehyde (HCHO) in air, snow, and interstitial air at Concordia (East Antarctic Plateau) in summer |
| VerfasserIn |
S. Preunkert, M. Legrand, M. M. Frey, A. Kukui, J. Savarino, H. Gallée, M. King, B. Jourdain, W. Vicars, D. Helmig |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 15, no. 12 ; Nr. 15, no. 12 (2015-06-17), S.6689-6705 |
| Datensatznummer |
250119834
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| Publikation (Nr.) |
 copernicus.org/acp-15-6689-2015.pdf |
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| Zusammenfassung |
| During the 2011/12 and 2012/13 austral summers, HCHO was investigated for the
first time in ambient air, snow, and interstitial air at the Concordia site,
located near Dome C on the East Antarctic Plateau, by deploying an Aerolaser
AL-4021 analyzer. Snow emission fluxes were estimated from vertical gradients
of mixing ratios observed at 1 cm and 1 m above the snow surface as well as
in interstitial air a few centimeters below the surface and in air just above the
snowpack. Typical flux values range between 1 and
2 × 1012 molecules m−2 s−1 at night and 3 and
5 × 1012 molecules m−2 s−1 at noon. Shading
experiments suggest that the photochemical HCHO production in the snowpack at
Concordia remains negligible compared to temperature-driven air–snow
exchanges. At 1 m above the snow surface, the observed mean mixing ratio of
130 pptv and its diurnal cycle characterized by a slight decrease around
noon are quite well reproduced by 1-D simulations that include snow emissions
and gas-phase methane oxidation chemistry. Simulations indicate that the
gas-phase production from CH4 oxidation largely contributes (66%)
to the observed HCHO mixing ratios. In addition, HCHO snow emissions account
for ~ 30% at night and ~ 10% at noon to the observed
HCHO levels. |
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