Spatiotemporal distributions and influences on snow density in China from 1999 to 2008

Ground snow observation data from 1999 to 2008 were used to analyze the temporal and spatial distribution of snow density in China. The monthly maximum density shifted from north to south during the period from October to the following January, and then moved back from south to north during the period from January to April. The maximum snow density occurred at the border between Hunan and Jiangxi provinces in January, where snow cover duration was short and varied remarkably. Snow density in Northeast China and the Xinjiang Uygur Autonomous Region were also high and showed less variation when the snow cover duration was long. Ground observation data from nine weather stations were selected to study changes of snow density in Northeast and Northwest China. A phase of stable snow density occurred from the middle ten days of November to the following February; non-stationary density phases were observed from October to the first ten days of November and from March to April. To further investigate the effects of climatic factors on snow density, correlations between snow density and precipitation, air temperature, snow depth and wind velocity for Northeast and Northwest China were analyzed. Correlation analysis showed that snow depth was the primary influence on snow density.