2024年8月7日出版的《大气科学进展》杂志发表了国防科技大学黄小刚教授团队的最新成果，他们报道了天气形势对中国四川盆地极端持续性暴雨时空特征及日变化的影响。

据研究人员介绍，中国四川盆地(SCB)是极持续强降雨(EPHR)事件的高发地区。2009-2019年的EPHR主要集中在北部、西北部迎风坡和中部盆地。集中发生在6-9月，以7月最为明显，在当地标准时间03点达到高峰。

在这里，研究人员使用ERA-5再分析资料和客观分类，以探讨天气模式及其影响。EPHR过程中出现了三种天气型，均伴有西南低涡。西南低涡的位置和强度、青藏高原(TP)热作用力和低空风对EPHR的强度和空间分布有重要影响。当西南涡旋位于南海西侧且存在偏南低空急流(LLJs)时，辐合和上坡风会导致西北或北部迎风坡发生EPHR。

如果没有LLJ，整个SCB处于西南涡中心，夜间EPHR受西南涡内环流和TP热作用力产生的上升气流控制，降水偏弱。SCB的东南入口是低空风主导EPHR夜间高峰的关键区域。关键区域夜间东南风增强被归因于惯性振荡，地形摩擦作用通过产生偏东和偏东北的地转风向盆地输送动量和水分。

附：英文原文

Title: Influence of Synoptic Pattern on the Spatiotemporal Feature and Diurnal Variation of Extremely Persistent Heavy Rainfall Over Sichuan Basin, China

Author: Fan Xia, Huang xiao gang, Jian-Fang Fei, ju wang, Xiaoping CHENG, Chi ZHANG

Issue&Volume: 2024-08-07

Abstract: The Sichuan Basin (SCB), China has a high incidence of extremely persistent heavy rainfall (EPHR) events. The EPHR from 2009 to 2019 in SCB was mainly concentrated in the northern and northwestern windward slopes and the central basin. It occurred from June to September, especially in July, and peaked at 03 local standard time. ERA-5 reanalysis data and the objective classification were used to investigate the synoptic patterns and their effect. There were three synoptic patterns during EPHR and they were all accompanied by the southwest vortex. The location and intensity of the southwest vortex, thermal forcing of Tibetan Plateau (TP), and low-level winds can greatly affect the intensity and spatial distribution of EPHR. When the southwest vortex was located in the western SCB and there were southerly low-level jets (LLJs), convergence and upslope wind would lead to EPHR on the northwestern or northern windward slopes.  If there was no LLJ and the whole SCB was in the center of the southwest vortex, the nocturnal EPHR was controlled by the internal circulation of the southwest vortex and the updraft generated by the thermal forcing of TP, and the rainfall was weaker. The southeastern entrance of SCB was a key area where the low-level wind dominated the nocturnal peak of EPHR. The nocturnal strengthened southeasterly wind in the key area is attributed to inertial oscillation, and the topographic friction plays an essential role in transporting momentum and moisture into the basin by generating easterly and northeasterly ageostrophic winds.

DOI: 10.1007/s00376-024-3358-9

Source: http://www.iapjournals.ac.cn/aas/en/article/doi/10.1007/s00376-024-3358-9viewType=HTML