摘要
利用青藏高原上72个常规气象观测站的逐日积雪厚度、冻结深度、气温、降水和地表温度资料,分析了高原积雪和季节冻土年际变化差异的原因.结果表明:气温和地表温度对高原积雪和季节冻土都有重要的影响,而降水对积雪的影响很重要,但是对季节冻土的影响则比较小.高原积雪对季节冻土有较大的影响,在积雪达到一定厚度以后,积雪的保温作用会影响冻结深度的变化,积雪越厚,保温作用越强;积雪越浅,保温作用越弱,当积雪小于某一厚度时其主要起降温作用.积雪的保温作用可能是积雪与季节冻土年际变化差异的原因之一.
In this paper the cause of the differentia in interannual variation between snow cover and seasonal frozen soil in the Tibetan Plateau is analyzed by using conventional meteorological observations in 72 stations, including daily snow depth, frozen soil depth, air temperature, precipitation and ground surface temperature. It is found that the changes of air temperature and ground surface temperature mostly affect snow cover and seasonal frozen soil, with a very good negative correlation between snow cover, as well as seasonal frozen soil, and air temperature, as well as ground surface temperature. Almost all the maximum/minimum depths of snow cover and seasonal frozen soil are corresponding to the minimum/maximum temperatures of air and ground surface. Precipitation also affects snow cover, but less influence seasonal frozen soil. Mostly, abnormal precipitation corresponds to abnormal snow cover, but abnormal precipitation hardly corresponds to abnormal seasonal frozen soil. The difference in impact factors may be the important cause of the differentia in interannual variation between snow cover and seasonal frozen soil. Snow cover has a great influence on seasonal frozen soil. When snow cover reaches to a certain depth, its heat preservation may affect the depth change of seasonal frozen soil. The thicker the snow cover is, the stronger the heat preservation is. The shallower the snow cover is, the weaker the heat preservation is. When snow cover is less than a certain depth, no heat preservation can be seen. The heat preservation of snow cover may be another important cause for the differentia of interannual variation between snow cover and seasonal frozen soil.
出处
《冰川冻土》
CSCD
北大核心
2004年第2期153-159,共7页
Journal of Glaciology and Geocryology
基金
中国科学院知识创新工程项目(KZCX1 10 07)
中国科学院知识创新工程重要方向项目(ZKCX2 SW 210)资助
