2016年01号台风“尼伯特”对一次梅雨期降雨影响的数值试验

本文应用分段位涡反演方法和中尺度WRF模式研究了2016年01号台风“尼伯特”对一次梅雨锋降水的影响，研究结果表明:减弱（增强）台风之后，降雨区的水汽通量增加7.34%（减少6.67%），动能增加7.78%（减少5.36%），对流有效位能增加6.66%（减少5.71%）。江淮地区降雨量出现累积降雨量增加10.21%（减少8.13%）。台风“尼伯特”在其加强、靠近中国大陆的过程中，迫使西太平洋副热带高压（简称副高）北抬东撤，阻碍了沿副高边缘输送至江淮地区的水汽和热量，间接导致该地区降水显著减少至消失；此外台风增强过程中，本体环流对于水汽和能量的消耗增大，导致孟加拉湾输送至江淮降雨区的水汽和能量的减少，直接导致梅雨锋降水过程中止。

A Numerical Study of Typhoon "Nepartak" Impacts on a Precipitation Event during Meiyu Period

In this paper, the effects of typhoon Nepartak on a Meiyu frontal precipitation event is explored by using the piecewise potential vorticity inversion method and the mesoscale WRF model. The results show that after weakening (strengthening) the typhoon, the water vapor flux over the rainfall area increased by 7.34% (decreased by 6.67%), the kinetic energy increased by 7.78% (decreased by 5.36%), the convective available potential energy increased by 6.66% (decreased by 5.71%), and accumulated precipitation in the Yangtze-Huaihe River basin increased by 10.21% (decreased by 8.13%). During the period when typhoon Nepartak was strengthening and approaching Mainland China, the subtropical high was forced to move northward and retreat eastward, which could directly prevent the water vapor and thermal energy from transporting to the Yangtze-Huaihe River basin along the edge of the subtropical high and indirectly lead to significant precipitation reduction and even disappearance in the area. In addition, accompanied with the intensification of typhoon, the depletion of water vapor and energy of the noumenon circulation increased, leading to decreases in water vapor and energy transport form the Bay of Bengal to Yangtze-Huaihe River basin. As a result, the Meiyu frontal precipitation terminated.