Chemical species, snowpack

The snowpack forms an interface between the atmosphere and the ground or sea ice that affects the energy balance of the Earth s surfaceand the exchange of chemical species between the surface and the atmosphere. Studies of snow areal extent (e.g. ref. 4) show that during the boreal winter snow covers about 14% of the Earth s surface, therefore affecting the surface energy balance at near-planetary scales, while its overall effect on tropospheric chemistry still needs to be assessed. 

Snowpack permeability determines air flow within the snowpack, as driven by differences in surface pressure between different parts of the snow surface. Air flow through the snow leads to the exchange of heat and of chemical species between the snow and the atmosphere and is the last physical variable discussed here. 

Adsorption. The concentration of adsorbed species in snow is determined by snow SSA, temperature and by the partial pressure of the species in snowpack interstitial air. Thus, the reduction in SSA usually observed during metamorphism will lead to the emissions of adsorbed species. Adsorbed species are also readily available for dark and light-induced chemical reactions. ... 

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