Macroscopic water vapor diffusion is not enhanced in snow

<p>Water vapor transport in dry snowpacks plays a significant role for snow metamorphism and the mass and energy balance of snowpacks. The molecular diffusion of water vapor in the interstitial pores is usually considered to be the main or only transport mechanism, and current detailed snow ph...

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Main Authors: K. Fourteau, F. Domine, P. Hagenmuller
Format: Article
Language:English
Published: Copernicus Publications 2021-01-01
Series:The Cryosphere
Online Access:https://tc.copernicus.org/articles/15/389/2021/tc-15-389-2021.pdf
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author K. Fourteau
F. Domine
F. Domine
P. Hagenmuller
author_facet K. Fourteau
F. Domine
F. Domine
P. Hagenmuller
author_sort K. Fourteau
collection DOAJ
description <p>Water vapor transport in dry snowpacks plays a significant role for snow metamorphism and the mass and energy balance of snowpacks. The molecular diffusion of water vapor in the interstitial pores is usually considered to be the main or only transport mechanism, and current detailed snow physics models therefore rely on the knowledge of the effective diffusion coefficient of water vapor in snow. Numerous previous studies have concluded that water vapor diffusion in snow is enhanced relative to that in air. Various field observations also indicate that for vapor transport in snow to be explained by diffusion alone, the effective diffusion coefficient should be larger than that in air. Here we show using theory and numerical simulations of idealized and measured snow microstructures that, although sublimation and deposition of water vapor onto snow crystal surfaces do enhance microscopic diffusion in the pore space, this effect is more than countered by the restriction of diffusion space due to ice. The interaction of water vapor with the ice results in water vapor diffusing more than inert molecules in snow but still less than in free air, regardless of the value of the sticking coefficient of water molecules on ice. Our results imply that processes other than diffusion play a predominant role in water vapor transport in dry snowpacks.</p>
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spelling doaj.art-331e9f4cf0594437a99164bc6e9a8c832022-12-21T22:27:46ZengCopernicus PublicationsThe Cryosphere1994-04161994-04242021-01-011538940610.5194/tc-15-389-2021Macroscopic water vapor diffusion is not enhanced in snowK. Fourteau0F. Domine1F. Domine2P. Hagenmuller3Univ. Grenoble Alpes, Université de Toulouse, Météo-France, CNRS, CNRM, Centre d'Études de la Neige, Grenoble, FranceTakuvik Joint International Laboratory, Université Laval (Canada) and CNRS-INSU (France), Québec, QC, G1V 0A6, CanadaCentre d'Études Nordiques (CEN) and Department of Chemistry, Université Laval, Québec, QC, G1V 0A6, CanadaUniv. Grenoble Alpes, Université de Toulouse, Météo-France, CNRS, CNRM, Centre d'Études de la Neige, Grenoble, France<p>Water vapor transport in dry snowpacks plays a significant role for snow metamorphism and the mass and energy balance of snowpacks. The molecular diffusion of water vapor in the interstitial pores is usually considered to be the main or only transport mechanism, and current detailed snow physics models therefore rely on the knowledge of the effective diffusion coefficient of water vapor in snow. Numerous previous studies have concluded that water vapor diffusion in snow is enhanced relative to that in air. Various field observations also indicate that for vapor transport in snow to be explained by diffusion alone, the effective diffusion coefficient should be larger than that in air. Here we show using theory and numerical simulations of idealized and measured snow microstructures that, although sublimation and deposition of water vapor onto snow crystal surfaces do enhance microscopic diffusion in the pore space, this effect is more than countered by the restriction of diffusion space due to ice. The interaction of water vapor with the ice results in water vapor diffusing more than inert molecules in snow but still less than in free air, regardless of the value of the sticking coefficient of water molecules on ice. Our results imply that processes other than diffusion play a predominant role in water vapor transport in dry snowpacks.</p>https://tc.copernicus.org/articles/15/389/2021/tc-15-389-2021.pdf
spellingShingle K. Fourteau
F. Domine
F. Domine
P. Hagenmuller
Macroscopic water vapor diffusion is not enhanced in snow
The Cryosphere
title Macroscopic water vapor diffusion is not enhanced in snow
title_full Macroscopic water vapor diffusion is not enhanced in snow
title_fullStr Macroscopic water vapor diffusion is not enhanced in snow
title_full_unstemmed Macroscopic water vapor diffusion is not enhanced in snow
title_short Macroscopic water vapor diffusion is not enhanced in snow
title_sort macroscopic water vapor diffusion is not enhanced in snow
url https://tc.copernicus.org/articles/15/389/2021/tc-15-389-2021.pdf
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