ACP Atmospheric Chemistry and Physics ACP 1680-7324 Copernicus GmbH Göttingen, Germany 10.5194/acp-11-4929-2011 Deposition of dinitrogen pentoxide, N<sub>2</sub>O<sub>5</sub>, to the snowpack at high latitudes Huff D. M. 1 2 Joyce P. L. 1 2 Fochesatto G. J. 2 3 Simpson W. R. 1 2 Department of Chemistry and Biochemistry, University of Alaska, Fairbanks, AK, USA Geophysical Institute, University of Alaska, Fairbanks, AK, USA Department of Atmospheric Science, University of Alaska, Fairbanks, AK, USA 26 05 2011 11 10 4929 4938 This is an open-access article ditributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. This article is available from http://www.atmos-chem-phys.net/11/4929/2011/acp-11-4929-2011.html The full text article is available as a PDF file from http://www.atmos-chem-phys.net/11/4929/2011/acp-11-4929-2011.pdf

Dinitrogen pentoxide, N<sub>2</sub>O<sub>5</sub>, is an important nighttime intermediate in the oxidation of NO<sub>x</sub> that is hydrolysed on surfaces. We conducted a field campaign in Fairbanks, Alaska during November 2009 to measure the gradient and derive a flux (and deposition velocity) of N<sub>2</sub>O<sub>5</sub> depositing to snowpack using the aerodynamic gradient method. The deposition velocity of N<sub>2</sub>O<sub>5</sub> under Arctic winter conditions was found to be 0.59 ± 0.47 cm s<sup>−1</sup>, which is the first measurement of this parameter to our knowledge. Based on the measured deposition velocity, we compared the chemical loss rate of N<sub>2</sub>O<sub>5</sub> via snowpack deposition to the total steady state loss rate and found that deposition to snowpack is at least 1/8th of the total chemical removal of N<sub>2</sub>O<sub>5</sub> that is located within the first few meters above the ground surface.

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