北半球大范围雪盖变化特征

The Variation Features of Large-Scale Snow Cover in Northern Hemisphere

The variation features and their correlations of snow cover area in three regions of North America, Eurasian continents and Tibet plateau in Northern Hemisphere were analyzed using NOAA / National Enviromental Satellite snow cover data of Northern Hemisphere from 1967 to 1983. The results show that there were different developing rules in the three regions. The annual variation of Eurasian snow cover was the most obvious in the three regions, the interannual change of Tibet plateau was the most obvious in the three regions. There were about 3 months, 6 months and 10 months periodic peaks in the changes of snow cover areas of North America and Eurasian, and 1.5 years, 3 years periodic peaks in Tibet plateau. There was a notable condensation in the changes of snow cover area of three regions on 6 years periodic oscillation, nevertheless Eurasian snowcovar falls behind North America about 2 months, falls backward Tibet plateau about 10.58 months.z