【摘要】 利用多源资料对2016年6月14—15日发生在湖南株洲的一次极端特大暴雨过程进行了多尺度特征分析。结果表明:强降雨位于地面冷锋南侧的暖区内,阻高崩溃形成的阶梯槽带动冷空气南下与南支槽前暧湿气流在湖南交汇是造成此次强降雨的高空环流背景,稳定维持的地面辐合线为其提供了触发机制;本次极端降雨由对流性降雨和稳定性降雨组成,日雨量与小时雨量创株洲市建站以来极值;强降雨发生在高层正涡度向低层正涡度增强、上升气流发展最强及西南气流加强的过程中,高层辐散强于低层辐合,辐散抽吸作用强;中尺度云团演变特征显示,株洲特大暴雨主要由三个中γ尺度云团发展融合而成,出现在中尺度云团发展到成熟阶段,暴雨落区位于云团西部边缘的TBB梯度大值区;雷达降水回波主要以低质心回波为主,强降水回波在株洲中部地区生消发展造成明显的"列车效应",速度径向剖面可见明显的底层逆风区,在其前部有较强的斜升气流,使对流风暴得以维持和发展。更多还原

【Abstract】 Based on multi-resource data, the multi-scale characteristics were analyzed for the extreme rainfall in Zhuzhou, Hunan Province during 14-15 June, 2016. The results show that the heavy rainfall is located in the warm zone on the south side of the cold front of the ground. Cold air southward and wet airflow in front of the south branch groove meets in Hunan is the background of the high-altitude circulation causing the heavy rainfall. A stably maintained ground convergence line provides a trigger mechanism for heavy rain. The extreme rainfall process broke the extreme values of daily rainfall and hourly rainfall since Zhuzhou station was built, which includes two stages of convection and stratification stability. The strong rainfall occurred in the process of increasing the positive vorticity from the upper layer to the lower layer, the strongest upward airflow and the stronger southwest current. The divergence in the upper layer is stronger than the convergence in the lower layer, so the divergence suction effect is strong. Mesoscale clouds showed that Zhuzhou torrential rain is mainly formed by the development and fusion of three meso-γ scale clouds, which appear in the stage from occurrence and development of meso-scale clouds to mature, and its falling area is located in the TBB gradient large area on the western edge of the clouds. The radar precipitation echo is mainly low centroid echo, and the strong precipitation echo causes obvious " train effect" in the development of Zhuzhou central region. The velocity radial profile shows obvious bottom upwind region, and there is strong oblique upward airflow in the front, which makes convective storm maintain and develop.更多还原