宁夏适宜人工增雨作业天气条件分析

利用宁夏24个测站1971～2000年常规地面观测中总云量、低云量、云状、降水量等资料，结合NCEP／NCAR（1971～2000年）逐日全球再分析资料，对宁夏30年层状云、对流云及混合云降水的时空分布及环流特征进行综合分析。结果表明：30年中，宁夏层状云降水次数明显多于对流云和混合云降水次数，是宁夏降水的主要类型；而大雨以上降水主要为混合云降水；宁夏南部地区以层状云降水为主，北部地区对流云和混合云降水次数相对较多。

Analysis of Suitable Conditions for Artificial Rainfall Enhancing Operation

Based on the total and low cloud cover, cloud form, precipitation data of 24 weather stations in Ningxia from 1971 to 2000, reanalyzed data of NCEP/NCAR in the same period, the spatial and temporal distribution of precipitation of stratiform cloud, convective cloud and mixed cloud and the circulation correspondingly are investigated. The results show that the number of precipitation times of stratiform cloud is much higher than that of the others and stratiform cloud precipitation is the main type of rainfall in 30 years. The heavy and torrential rainfalls are caused by mixed clouds. In the southern part of Ningxia, the stratiform cloud precipitation plays an important role, and in the northern part, convective and mixed cloud precipitations are crucial. Based on the results above, the suitable precipitation enhancing operation/nodes are discussed under different circulation and weather conditions.