气候变化领域集成服务门户

This paper studies the characteristics of snow cover variations for the Tibetan Plateau (TP) region (25 degrees-45 degrees N, 65 degrees-105 degrees E). The TP region‘s daily snow cover data are a subset of the Interactive Multisensor Snow and Ice Mapping System (1MS) 24 km-by-24 km snow cover dataset for the entire Northern Hemisphere. A database of the daily snow cover for the TP region was developed from Febtuary 4, 1997-March 15, 2012, Thus, an animation of the TP snow cover was made as a data product of this research. The maximum percentage snow cover (67 %) occurred on February 6, 2008 and the minimum (0.5 O/o) on September 1, 2009. The average snow cover is 16 %. The seasonal cycle of the monthly TP snow cover reaches maximum in January (about 37 A) and minimum in August (2 %). The trend of the snow cover reduction is 4.0 ‘Yo per decade, with a total reduction of 5.7 % from February 4, 1997 to March 15, 2012, The Hilbert Huang Transform and Fourier spectral analyses indicate the existence of a cycle of TP snow cover having a period of 2-3 years. The histogram and higher statistics moment analyses imply that the positive skewness favors more spring snowstorms than spring droughts and the sharp peakedness at the climatology indicates the snow cover predictability by climate normals.