甘肃省春季沙尘暴强弱年份大气环流特征对比分析

Contrast Analysis on The Atmospheric Circulation Between Active And Inactive Years of Spring Sandstorms in Gansu

文中使用NCEP/NCAR1955～2000年全球月平均再分析网格点资料(2.5°×2.5°纬度/经度)和甘肃省区域性沙尘暴过程资料,分别选取了甘肃省5个春季典型沙尘暴年份和5个春季非沙尘暴年份,对其气候平均的大尺度环流场和有关物理量场的动力和热力结构差异进行了对比分析。初步探讨了甘肃省春季沙尘暴发生与全球海温异常的关系。分析结果表明,甘肃省春季沙尘暴年和非沙尘暴年大尺度高低空环流场和有关物理量场差异明显,从而揭示了沙尘暴形成的大尺度环流以及动力和热力因子影响的事实,以期对我国西北地区沙尘暴气候成因有更全面深入的了解,为沙尘暴短期气候预测提供理论依据和强信号。

Based upon the regional sandstorm records in Gansu, the geopotential height, temperature and wind fields at mandatory levels generated by NCEP/NCAR reanalysis dataset(2.5°×2.5°Lat/Lon) for 46 years(1955～2000), The 5 active sandstorm years and the 5 inactive sandstorm years in spring over Gansu are selected respectively to contrast the difference on the large-scale atmospheric circulation and the relevant dynamical and thermodynamic factors. The results show that the climatic circulation backgrounds between more and less spring sandstorm in Gansu are evidently different. Therefore, it is revealed the facts that the anomalies of the large-scale circulation and the relevant dynamic and thermodynamic factors can result in the formation of spring sandstorm in Gansu. So that the climatic causes of sandstorm in Northwest China can be understood very well. Above preliminary results have some novel and applied value for the climatic prediction of the sandstorm in Northwest China.