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Influence of snow processes on surface exchange of mass and energyтезисы доклада
- Авторы: Lehning M., Bartelt P., Exner T., Fierz C., Meirold–Mautner I., Raderschall N., Sokratov S.
- Сборник: XXIII General Assembly of the International Union of Geodesy and Geophysics; June 30–July 11, 2003; Sapporo, Japan: Abstracts Week B
- Тезисы
- Год издания: 2003
- Место издания: International Union of Geodesy and Geophysics IUGG2003 Local Organizing Committee Sapporo
- Первая страница: JSM10/07A/B23-004 (p. B.63)
- Аннотация: There are many influences of snow on the surface exchanges of mass, energy and momentum. The most important ones are: a) Change of surface albedo through snow on the ground; b) Change of surface roughness through snow on the ground; c) Change of surface roughness through drifting snow; d) Change of latent heat transfer (sublimation) through drifting snow; e) Insulation of soil layers and vegetation through snow on the ground. When analyzing the processes in more detail, it becomes clear that all exchange processes are highly interdependent and cannot be separated from the processes that take place within the snow cover. For example, metamorphic changes of surface snow such as the formation of a wind slab or a melt-freeze crust will prevent subsequent erosion of the snow. Or erosion of snow will create surface ripples and sastrugis with the effect of changing surface momentum and heat fluxes. Another example is the dependence of the surface latent heat flux on ventilation and vapor flux in the upper snow layers. Thus, the correct representation of snow processes is a crucial part in assessing the snow ・atmosphere interaction This presentation gives an overview of the relevant processes at the snow ・atmosphere interface. It shows how these processes are represented in the detailed snow cover model SNOWPACK. Focus is on the interaction between latent heat and thus moisture fluxes, surface roughness, vapor transport within the snow and snow ventilation effects as well as radiation transfer in snow. The energy balance over and in the snow cover is discussed using field data from summit at Greenland, from the Weissfluhjoch experimental site at Davos Switzerland and laboratory data from the cold wind tunnel in Davos Switzerland. It is shown that the correct representation of the snow processes is necessary to close the energy balance. At the same time, snow development itself depends crucially on these processes. Applications of such a detailed model are discussed, which include avalanche warning, ice core interpretation and ecological research.
- Добавил в систему: Сократов Сергей Альфредович