中文摘要：

利用NCEP/NCAR地面感热通量再分析格点资料， 分析了1951-2010年青藏高原（下称高原）地区地面感热通量的基本气候特征、 年际与年代际变化及其空间分布， 采用滑动t检验和小波分析研究了高原年平均感热通量变化的突变特征， 并分析了影响高原感热变化的因素以及探讨了高原感热的变化对东亚、 南亚夏季风的影响。结果表明, 就全年平均而言， 高原感热通量大部分地区为正值， 说明高原为热源； 冬季是全年感热通量最小的季节， 为负值； 其余季节感热均为正值， 即由地面向大气输送感热。近60年高原的感热通量出现了不同程度的减少， 春、 夏季呈现出不显著的下降趋势， 秋、 冬季和年平均感热通量的下降趋势比较显著， 分别为0.94， 0.50和0.49 W·m-2·（10a）-1。感热线性趋势的空间分布具有季节性和区域性差异。由于1969年前后的突变， 导致高原感热在1970-1981年的下降趋势显著。高原感热的变化与气温呈负相关， 与风速和地温呈正相关， 与降水的关系不明显。年际尺度上， 春季、 年平均高原感热的减弱（增强）区域和东亚、 南亚夏季风指数有很好的正（负）相关， 其显著变化可能会在某种程度上影响东亚、 南亚夏季风。

英文摘要：

Using the analyzed surface sensible heat flux （SHF） grid data provided by NECP/NCAR, the basic temporal-spatial distribution and evolution features of surface SHF over Qinghai-Xizang （Tibetan） Plateau （QXP） had been systematically investigated during the period 1950-2010 based on moving t test and wavelet analysis. The influence factors of surface SHF variation were analyzed using different data. Meanwhile, the influence of surface SHF change on Asia summer monsoon was discussed. The result shows that the annual average surface SHF is positive in most parts of QXP, accounting for QXP being a heat source. The average value of the surface SHF over QXP merely appears a weak negative value in the winter. And it is positive in the rest seasons, that is, heat flux＇s translated from ground to atmosphere. The surface SHF presented weak downward trend in the spring and summer during the last 60 years, but not significantly. However, prominent downward trend appeared in the annual mean change, winter and autumn, and annual mean sensible heat flux has weakened by 0.49 W·m-2·（10a）-1, autumn and winter for 0.94 and 0.50 W·m-2·（10a）-1, respectively. The spatial distribution of linear trend had seasonal and regional differences. During the period from 1970 to 1981, the downtrend of surface SHF is extremely remarkable on QXP due to the abrupt climate change around 1969. There are negative correlation between SHF and air temperature, positive correlation between SHF and wind speed and surface temperature, no obvious relationship with precipitation over QXP. Furthermore, there are positive （negative） correlation between the weakening （strengthening） of SHF and Asian summer monsoon. Therefore, its significance variation may affect Asian summer monsoon to some extent at the interannual scale.