柴达木盆地区域性中到大雨个例分析

应用平均场资料,对2005年7月7~10日柴达木盆地东部出现的区域性中到大雨天气过程进行了综合分析。结果表明:此次区域性中到大雨过程的发生与巴尔喀什湖低槽不断分裂的小槽、柴达木盆地对流层中低层的低涡(切变)和副高外围强盛发展的西南暖湿气流的共同作用密切相关。对流层中低层辐合、高层辐散和高湿度区的维持,以及强散度柱、强涡度柱耦合和高低空急流的稳定维持是产生这次区域性中到大雨天气过程的主要原因。

Case Study of a Regional Heavy Rain over Northwestern Qinghai Province

The regional synoptic process with moderate-to-heavy rain appeared in the eastern Chaidamu basin on 7 to 10 July 2005 is analyzed by means of the averaged field data.It is closely correlated with the branch trough separated from the Balkhash low trough and the low-vortex shear in the lower/middle troposphere over the Chaidamu basin,as well as the southwest warm/wet air around the subtropical high.The convergence in the middle troposphere,the maintenance of divergence in the upper troposphere and high humidity,the coupling of strong vorticity and stability columns and the maintenance of the upper/lower jet flow are the main causes of the moderate to heavy synoptic weather process.