2017年7月6-9日九江市柴桑区晴空连续大风成因分析

Chaisang District, Jiujiang City, July 6-9, 2017 Cause Analysis of Continuous Gale in Clear Sky

对2017年7月6-9日柴桑区地面大风的影响机制进行了综合分析,主要结论有:此次晴空连续偏南大风的原因是6-9日夜间柴桑区高空和近地层出现强辐散,中层辐合,小尺度气压扰动,低空出现西南急流的脉动,动量下传,同时柴桑区的特殊地形,东倚庐山,西靠岷山,中间为盆地,形成东北-西南向的峡谷,南端德安县宽,北面柴桑区窄,如果吹西南风,柴桑区正处于喇叭口的出口处,有明显狭管效应。而东面庐山的阻挡与热力作用也会增强经过柴桑区的西南风,利于偏南大风的形成。

This paper makes a comprehensive analysis of the influencing mechanism of the Surface Gale in Chaisang area from July 6 to 9, 2017. The main conclusions are as follows: the reason for the continuous South gale in the clear sky is the strong divergence, convergence in the middle layer, small-scale pressure disturbance, the fluctuation of southwest jet at low altitude and the downward transmission of momentum in the upper and near strata of Chaisang area during the night of June 9. At the same time, the special topography of Chai-Sang area, which relies on Lushan Mountain in the East and Minshan Mountain in the west, has a basin in the middle, forming a northeast-southwest canyon. The southern end of De’an County is wide, and the northern Chai-Sang area is narrow. If the southwest wind blows, Chai-Sang area is at the exit of the trumpet mouth, with obvious narrow tube effect. The blocking and thermodynamic effects of the Lushan Mountains on the East will also enhance the southwest wind passing through the Chaishang area, which is conducive to the formation of the southerly gale.