Meteorological Knowledge Useful for the Improvement of Snow Rain Separation in Surface Based Models

Hydrology

Angela Lundberg¹  Nils Sandström¹  William Graff²  David Gustafsson³  James Feiccabrino⁴ 

[1] Department of Civil, Environmental and Natural Resources Engineering, Lulea University, Lulea 971-87, Sweden;Operational Weather Squadron, United States Air Forces in Europe, Kapuan Air Base, APO-AE 09021, Germany;Research and Development, Hydrology, Swedish Meteorological and Hydrological Institute, Norrköping 601-76, Sweden;Water Resources Engineering, Lund University, Lund S-221 00, Sweden;

关键词: precipitation phase;    snow;    snow modeling;    hydrology;    meteorology;    hydrometeorology;    phase change;   

DOI  :  10.3390/hydrology2040266

来源: DOAJ

【 摘 要 】

An accurate precipitation phase determination—i.e., solid versus liquid—is of paramount importance in a number of hydrological, ecological, safety and climatic applications. Precipitation phase can be determined by hydrological, meteorological or combined approaches. Meteorological approaches require atmospheric data that is not often utilized in the primarily surface based hydrological or ecological models. Many surface based models assign precipitation phase from surface temperature dependent snow fractions, which assume that atmospheric conditions acting on hydrometeors falling through the lower atmosphere are invariant. This ignores differences in phase change probability caused by air mass boundaries which can introduce a warm air layer over cold air leading to more atmospheric melt energy than expected for a given surface temperature, differences in snow grain-size or precipitation rate which increases the magnitude of latent heat exchange between the hydrometers and atmosphere required to melt the snow resulting in snow at warmer temperatures, or earth surface properties near a surface observation point heating or cooling a shallow layer of air allowing rain at cooler temperatures or snow at warmer temperatures. These and other conditions can be observed or inferred from surface observations, and should therefore be used to improve precipitation phase determination in surface models.

【 授权许可】

Unknown