Spatiotemporal changes in snow cover over China during 1960–2013

Snow cover is highly sensitive to global warming, and it, in return, has huge impacts on global and regional climate change. Because of the limitations of in-situ observations, only a few studies have analyzed the dynamics of snow cover across the whole of China. In this study, we studied the spatio-temporal variabilities of snow cover over China and explored the covary of snow cover with precipitation and temperature in spring and winter based on the surface snow cover observations of 201 meteorological stations in China during 1960–2013. The temporal and spatial distribution characteristics of the mean daily snow depth and the number of snow cover days were analyzed. Results showed snow depth and the number of snow-cover days were high in Northeast China, Eastern China-Inner Mongolia, Northern Xinjiang, Southeastern and South Region of the Tibetan Plateau. The trend of snow depth and the number of snow-cover days varied among different regions. Snow depth recorded at 34.3% of the stations showed an increasing trend during the study period. There were increasing trends of the snow-cover days at 40.8% of stations. Increasing trends of the mean annual daily snow depth and the number of snow-cover days were statistically insignificant (p > 0.05) while an abrupt change of the number of snow cover days was found in 1975. Change points of the mean daily snow depth in autumn and winter occurred in 1987 and 2008, respectively. Change points of the number of snow-cover days in spring and winter occurred in 2009 and 1983, respectively. Snow cover in China covaried with various climate factors, i.e., precipitation or temperature. This study improved our knowledge on snow cover changes and is beneficial for further studies on climate change in China.