青藏高原地区季风特征及与我国气候异常的联系

RELATIONSHIP BETWEEN QINGHAI-XIZANG PLATEAU REGION MONSOON FEATURES AND ABNORMAL CLIMATE IN CHINA

  • 摘要: 利用1951~2000年NCEP/ NCAR 600 hPa逐日再分析资料, 计算候时间尺度能够代表青藏高原地区季风特征的高度场指数序列, 研究青藏高原高度场指数的基本特征及其年代际变化趋势。结果表明:青藏高原地区600 hPa夏季为低压, 冬季为高压, 夏季低压形成的时间呈提早的趋势, 夏季低压强度也呈增强趋势; 青藏高原高度场指数年变化与高原雨日的年变化基本相似。夏季青藏高原高度场指数与同期我国160站的降水和气温相关表明:与降水相关分布从华北到华南呈“-+-”东西向带状分布; 冬季高原高压强度指数与同期气温均为正相关, 青藏高原东侧边缘区和华南地区正相关最为显著。

     

    Abstract: Time series of pentad mean 600 hPa height indices of Qinghai-Xizang Plateau region Monsoon features and derived from 1951—2000 NCEP/NCAR reanalysis of daily gridded data (2.5 °×2.5°), with which to investigate basic features and trends of Qinghai-Xizang Plateau high field index (QXPFI) on an interdecadal basis. Results indicate that the 600 hPa level is under the control of a low (high) in summer (winter), with the low tending to appear ahead of time and intensity progressively, on the whole, the annual variation in the indices is similar to that of the number of rainy days in Qinghai-Xizang Plateau. Moreover, correlation of QXPFI to the 160-station precipitation and air temperature in China shows that, on a simultaneous basis, the indices are significantly correlated to the precipitation as "﹣+﹣ " in zonal bands from northern to southern China, and the indices display a positive correlation with winter temperature, which is most significant over eastern edge of Qinghai-Xizang Plateau and South China.

     

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