中国暖区暴雨的研究进展

利用常规气象观测、多普勒天气雷达、风云2G卫星、ERA5再分析资料，基于多尺度子空间变换及局地多尺度能量分析方法，对2020年1月24—26日广西沿海一次漏报的暖区暴雨天气进行了诊断研究，结果表明：暖区暴雨期间南支槽前西南急流的暖湿输送为暴雨发生提供有利背景场；对流系统不断在越南东北部喇叭口地形作用下触发，受高层气流引导移入广西沿海一带造成明显降水；暖区暴雨的发生发展主要由对流尺度动能主导，两者演变具有较好的匹配关系；对流能量主要来源于对流层中、低层，而在对流层高层为能量的流失；背景尺度向对流尺度的动能转换贡献最大；对流层中层、低层背景流场的正压失稳主导了暖区暴雨的发展；对流层中层对流尺度有效位能向动能的浮力转换进一步促进了系统的发展；动能的空间输送使得对流动能在空间上均匀分配，有利于对流系统平稳发展，使其维持较长生命史并移动较远距离造成多地降水；天气尺度动能转换和气压梯度力做功的贡献很小，体现了暖区暴雨弱天气尺度强迫的性质。

A review of the warm-sector rainstorms in China

Based on multiscale diagnosis method of energy budget, the missing-forecast coastal warm-sector rainstorm process of Guangxi occurred in 24-26 January 2020 was analyzed by using the stational data, Doppler radar, FY-2G satellite data and the ERA5 reanalysis data. The results are shown below: The warm and moisture southwest jet in front of the southern branch trough provides a favorable synoptic condition for the rainstorm. The convection system was constantly triggered by the trumpet topography in the northeast of Vietnam, and moved northeastward to the coastal of Guangxi, which was influenced by the upper level airflow and produced significant amount of precipitation. It is found that the occurrence and development of warm-sector rainstorm were mainly dominated by the convection-scale kinetic energy that correlated well with the former in evolution. The convective energy mainly come from the middle and lower troposphere and losts in the upper troposphere. The kinetic energy from the background scale contributed the most, and the barotropic instability of the background flow field in the middle and lower troposphere dominated the development of rainstorm in the warm-sector. The buoyancy conversion of convection-scale available potential energy to kinetic energy in the middle troposphere further promoted the development of system. The transport of kinetic energy made the convection-scale kinetic energy distribute evenly spatially, which led to the stable development of the convective system and enabled it to maintain for long time and thus produce large amount of precipitation over its path. The contribution of synoptic-scale kinetic energy conversion and pressure gradient work is small, which reflects the nature of weak synoptic-scale forcing of warm-sector rainstorm.