摘要
2008年7月20～22日甘肃河东出现了一次区域性暴雨天气，对这次过程的环流形势演变、主要影响系统和物理量场特征进行分析。结果表明：在有利的环流形势下，高原低涡东移发展是造成此次强降水的主要系统；低空急流为此次暴雨提供了充足的水汽；低层辐合、高层辐散的流场形势引起强烈上升运动，为暴雨的发生和维持提供了很好的动力条件，保证了降水云系的发展和维持；比湿和假相当位温分布对暴雨落区预报有一定的指示意义。
A regional rainstorm occurred in the east of Gansu Province from July 20 to 22, 2007 was analyzed from the circulation evolution, the main influence system and the features of physical quantity fields. Results show that the low - level jet provided sufficient moisture for the rainstorm, and the air stream convergence at low level and divergence at high level resulted in strong ascent motion, which was valuable for occurrence and maintain of the rainstorm, and ensured the development and maintenance of the precipitation cloud. The distribution of specific humidity and the pseudo - equivalent potential temperature has an indicative significance in prediction of rainstorm zone.
出处
《干旱气象》
2009年第3期271-275,293,共6页
Journal of Arid Meteorology
关键词
区域性暴雨
低涡
低空急流
物理量场
regional heavy rain
low vortex
low level jet stream
physical quantity field
