Correlations of snow depth retrieved from SSM/I with precipitation and temperature over China

Climatological data during the period 1978-2005 in China were analyzed to characterize the relationships between temperature, precipitation (rainfall and snow), and snow as well as their temporal variations. Data at forty-two observation sites among 160 sites are chosen for the analysis. The China domain is broadly divided into northeastern, northwestern, and Tibet regions. The results show that the evolution of snow depth and area is in good agreement with that from previous studies using different datasets. An abrupt jump occurred in the year 1990. Oscillations with a wavelength of about five years can be identified in the time sequence. Significant correlations between snow depths, snow covers, temperatures, and precipitation are found for various time frames at different sites. The cold air mass comes from the northwestern and northeastern China and moves into the southern China through an aisle between them. This cold air transportation brings the influence of snow information on the temperature and precipitation into the southern China. In the sensitive region, the snow information in the three regions has strong effects on the temperature and precipitation. The actual effect of snow information on temperature and precipitation is the result of competition among these three snow covered regions. The snow information in the Tibet region has a larger scale effect on the temperature and precipitation than in the other two regions. This is in accordance with its characteristics that are able to inspire the larger scale atmospheric circulations.