Formaldehyde in the Alaskan Arctic snowpack: Partitioning and physical processes involved in air-snow exchanges
The snowpack is a photochemically active medium which produces numerous key reactive species involved in the atmospheric chemistry of polar regions. Formaldehyde (HCHO) is one such reactive species produced in the snow, and which can be released to the atmospheric boundary layer. Based on atmospheri...
Published in: | Journal of Geophysical Research |
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Language: | English |
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American Geophysical Union
2011
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Online Access: | http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-011-003 https://doi.org/10.1029/2011JD016038 |
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ftncar:oai:drupal-site.org:articles_12147 2023-09-05T13:17:05+02:00 Formaldehyde in the Alaskan Arctic snowpack: Partitioning and physical processes involved in air-snow exchanges Barret, Manuel (author) Domine, Florent (author) Houdier, Stephan (author) Gallet, Jean-Charles (author) Weibring, Petter (author) Walega, James (author) Fried, Alan (author) Richter, Dirk (author) 2011-09-17 application/pdf http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-011-003 https://doi.org/10.1029/2011JD016038 en eng American Geophysical Union Journal of Geophysical Research-Atmospheres http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-011-003 doi:10.1029/2011JD016038 ark:/85065/d7tx3g2q Copyright 2011 American Geophysical Union. Troposphere: composition and chemistry Arctic region Boundary layer processes Snow Cryosphere Text article 2011 ftncar https://doi.org/10.1029/2011JD016038 2023-08-14T18:41:15Z The snowpack is a photochemically active medium which produces numerous key reactive species involved in the atmospheric chemistry of polar regions. Formaldehyde (HCHO) is one such reactive species produced in the snow, and which can be released to the atmospheric boundary layer. Based on atmospheric and snow measurements, this study investigates the physical processes involved in the HCHO air-snow exchanges observed during the OASIS 2009 field campaign at Barrow, Alaska. HCHO concentration changes in a fresh diamond dust layer are quantitatively explained by the equilibration of a solid solution of HCHO in ice, through solid-state diffusion of HCHO within snow crystals. Because diffusion of HCHO in ice is slow, the size of snow crystals is a major variable in the kinetics of exchange and the knowledge of the snow specific surface area is therefore crucial. Air-snow exchanges of HCHO can thus be explained without having to consider processes taking place in the quasi-liquid layer present at the surface of ice crystals. A flux of HCHO to the atmosphere was observed simultaneously with an increase of HCHO concentration in snow, indicating photochemical production in surface snow. This study also suggests that the difference in bromine chemistry between Alert (Canadian Arctic) and Barrow leads to different snow composition and post-deposition evolutions. The highly active bromine chemistry at Barrow probably leads to low HCHO concentrations at the altitude where diamond dust formed. Precipitated diamond dust was subsequently undersaturated with respect to thermodynamic equilibrium, which contrasts to what was observed elsewhere in previous studies. Article in Journal/Newspaper Arctic Barrow Alaska OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) Arctic Journal of Geophysical Research 116 |
institution |
Open Polar |
collection |
OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) |
op_collection_id |
ftncar |
language |
English |
topic |
Troposphere: composition and chemistry Arctic region Boundary layer processes Snow Cryosphere |
spellingShingle |
Troposphere: composition and chemistry Arctic region Boundary layer processes Snow Cryosphere Formaldehyde in the Alaskan Arctic snowpack: Partitioning and physical processes involved in air-snow exchanges |
topic_facet |
Troposphere: composition and chemistry Arctic region Boundary layer processes Snow Cryosphere |
description |
The snowpack is a photochemically active medium which produces numerous key reactive species involved in the atmospheric chemistry of polar regions. Formaldehyde (HCHO) is one such reactive species produced in the snow, and which can be released to the atmospheric boundary layer. Based on atmospheric and snow measurements, this study investigates the physical processes involved in the HCHO air-snow exchanges observed during the OASIS 2009 field campaign at Barrow, Alaska. HCHO concentration changes in a fresh diamond dust layer are quantitatively explained by the equilibration of a solid solution of HCHO in ice, through solid-state diffusion of HCHO within snow crystals. Because diffusion of HCHO in ice is slow, the size of snow crystals is a major variable in the kinetics of exchange and the knowledge of the snow specific surface area is therefore crucial. Air-snow exchanges of HCHO can thus be explained without having to consider processes taking place in the quasi-liquid layer present at the surface of ice crystals. A flux of HCHO to the atmosphere was observed simultaneously with an increase of HCHO concentration in snow, indicating photochemical production in surface snow. This study also suggests that the difference in bromine chemistry between Alert (Canadian Arctic) and Barrow leads to different snow composition and post-deposition evolutions. The highly active bromine chemistry at Barrow probably leads to low HCHO concentrations at the altitude where diamond dust formed. Precipitated diamond dust was subsequently undersaturated with respect to thermodynamic equilibrium, which contrasts to what was observed elsewhere in previous studies. |
author2 |
Barret, Manuel (author) Domine, Florent (author) Houdier, Stephan (author) Gallet, Jean-Charles (author) Weibring, Petter (author) Walega, James (author) Fried, Alan (author) Richter, Dirk (author) |
format |
Article in Journal/Newspaper |
title |
Formaldehyde in the Alaskan Arctic snowpack: Partitioning and physical processes involved in air-snow exchanges |
title_short |
Formaldehyde in the Alaskan Arctic snowpack: Partitioning and physical processes involved in air-snow exchanges |
title_full |
Formaldehyde in the Alaskan Arctic snowpack: Partitioning and physical processes involved in air-snow exchanges |
title_fullStr |
Formaldehyde in the Alaskan Arctic snowpack: Partitioning and physical processes involved in air-snow exchanges |
title_full_unstemmed |
Formaldehyde in the Alaskan Arctic snowpack: Partitioning and physical processes involved in air-snow exchanges |
title_sort |
formaldehyde in the alaskan arctic snowpack: partitioning and physical processes involved in air-snow exchanges |
publisher |
American Geophysical Union |
publishDate |
2011 |
url |
http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-011-003 https://doi.org/10.1029/2011JD016038 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Barrow Alaska |
genre_facet |
Arctic Barrow Alaska |
op_relation |
Journal of Geophysical Research-Atmospheres http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-011-003 doi:10.1029/2011JD016038 ark:/85065/d7tx3g2q |
op_rights |
Copyright 2011 American Geophysical Union. |
op_doi |
https://doi.org/10.1029/2011JD016038 |
container_title |
Journal of Geophysical Research |
container_volume |
116 |
_version_ |
1776198397381836800 |