2023年7月10~12日海北中到大雨天气成因分析

Analysis of Causes of Moderate to Heavy Rain in Haibei from July 10~12, 2023

摘要: 本文利用站点实况数据、MICAPS数据、刚察风廓线雷达数据以及ERA5再分析资料研究了2023年7月10~12日青海省海北州出现的中到大雨天气过程，结果表明：此次天气过程发生发展与维持的动力条件来自高层南亚高压、中层短波槽及低层切变和热低压共同形成的高低空配置；孟加拉湾的水汽是此次强降水过程的主要水汽来源，西南气流在海北地区低层的动力输送下形成充沛的水汽供应；高温、高湿的环境贮存了较强的不稳定能量，中尺度系统的动力抬升和冷空气的入侵均有利于触发不稳定能量的释放，进一步增强了强对流天气的发生发展，导致短时强降水的出现；刚察风廓线雷达显示强降水开始前探测高度迅速增大，有短波槽在降水时段过境。

Abstract: In this paper, using the site data, MICAPS data, wind profile radar data and ERA5 reanalysis data, we studied the moderate to heavy rain weather process in Haibei Prefecture, Qinghai Province from July 10 to 12, 2023. The results show that: the dynamic conditions for the development and maintenance of the weather process came from the high and low altitude configuration formed by the upper South Asian high pressure, the middle short-wave trough, and the low level shear and thermal low pressure. The water vapor in the Bay of Bengal is the main source of water vapor in the heavy precipitation process, and the southwest airflow forms abundant water vapor supply under the power transport of the lower level in Haibei area. High temperature and high humidity store strong unstable energy. The dynamic uplift of mesoscale system and the intrusion of cold air are conducive to triggering the release of unstable energy, which further enhances the occurrence and development of strong convective weather and leads to the emergence of short-term heavy precipitation. Just observed wind profile radar showed that the detection height increased rapidly before the onset of heavy precipitation, and there was a short-wave trough passing through the precipitation period.