Advances in newly-fallen snow density research

The prediction of newly-fallen snow depth is a key and difficult task for winter meteorological service in Northern China. The es-timation of newly-fallen snow density is its essential technology. In this paper we review the important influencing factors on newly-fallen snow density, and introduce and compare several most widely applied estimating methods. Then we discuss their characteristics, limitations and the relations among them. Finally, we envision the developing direction of newly-fallen snow density estimation in the future. The main conclusions are as follows. (1) Temperature, wind speed, humidity, solar radiation and precipitation are important meteorological factors af-fecting newly-fallen snow density. (2) At present, the most widely used newly-fallen snow density estimation methods include those assum-ing a constant, building formulae, performing post diagnosis and invoking microphysical processes. They all have their own characteristics and limitations, and have fore-and-aft connections. (3) The relatively scientific post diagnosing and microphysical processes methods have their own relative superiorities and deficiencies that are difficult to overcome. The developing of newly-fallen snow density estimation needs the mutual promoting and common progress of those two methods.