Formaldehyde (HCHO) in air, snow and interstitial air at Concordia (East Antarctic plateau) in summer

Preunkert, S.; Legrand, M.; Frey, M. ORCID: https://orcid.org/0000-0003-0535-0416; Kukui, A.; Savarino, J.; Gallee, H.; King, M.; Jourdain, B.; Vicars, W.; Helmig, D.. 2015 Formaldehyde (HCHO) in air, snow and interstitial air at Concordia (East Antarctic plateau) in summer. Atmospheric Chemistry and Physics, 15. 6689-6705. 10.5194/acp-15-6689-2015

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Abstract/Summary

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.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	10.5194/acp-15-6689-2015
Programmes:	BAS Programmes > BAS Programmes 2015 > Atmosphere, Ice and Climate
ISSN:	1680-7316
Date made live:	05 Jan 2015 13:59 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/509066

Item Type:

Publication - Article

Digital Object Identifier (DOI):

10.5194/acp-15-6689-2015

Programmes:

BAS Programmes > BAS Programmes 2015 > Atmosphere, Ice and Climate

ISSN:

1680-7316

Date made live:

05 Jan 2015 13:59 +0 (UTC)

URI:

https://nora.nerc.ac.uk/id/eprint/509066