| 一次秋季台风倒槽大暴雨过程诊断及中尺度分析 |
| |
| 引用本文： | 王丽芳,张雪蓉,廖一帆,濮梅娟.一次秋季台风倒槽大暴雨过程诊断及中尺度分析[J].气象科学,2021,41(2):209-220. |
| |
| 作者姓名： | 王丽芳 张雪蓉 廖一帆 濮梅娟 |
| |
| 作者单位： | 嘉定区气象局, 上海 201800;中国气象局交通气象重点开放实验室, 南京 210009;南京气象科技创新研究院, 南京 210009;南京信息工程大学, 南京 210044;南京信息工程大学, 南京 210044;江苏省气象台, 南京 210008 |
| |
| 基金项目： | 国家自然科学基金资助项目(41805036);江苏省气象学会青年科研基金项目(KQ201908);上海市气象局"青年起航计划" |
| |
| 摘 要： | 利用FNL再分析资料,结合加密自动站、多普勒雷达、卫星资料和数值模式预报产品,对2018年9月16—17日长三角地区一次典型的秋季台风倒槽大暴雨进行了分析。结果表明:大暴雨是在远距离台风倒槽、低空急流和高空槽共同影响下,由冷暖空气持续交汇激发的4个中尺度对流云团活动造成。第一阶段长江口区强暴雨发生在3号云团快速增强期间,暴雨出现在云团北侧TBB梯度大值区中,雨强随云顶温度降低快速增强;4号云团缓慢东移造成第二阶段暴雨,降水累积效应使长江口区降水量进一步加大。东北风(偏北风)与东南风(偏东风)形成的地面中尺度辐合线是暴雨的关键触发机制,气旋性辐合中心的形成对雨团增幅具有重要作用。多普勒雷达径向速度场上中气旋的形成提前于强暴雨增幅约30 min,具有良好的先兆性和预报预警意义。(超)低空急流持续的水汽和能量输送、高低空急流耦合及冷空气侵入形成的倾斜上升支和垂直环流圈、上干冷下暖湿的对流不稳定层结有利于中尺度暴雨云团的形成和维持。表征冷暖空气结合的地面辐合线位置是暴雨落区预报的关键,对于秋季台风倒槽暴雨,要特别重视冷空气对暴雨的触发和增幅作用,基于实况资料监测及时订正模式预报结论。
|
| 关 键 词： | 大暴雨 台风倒槽 冷空气 中尺度云团 地面中尺度辐合线 |
| 收稿时间： | 2019/10/21 0:00:00 |
| 修稿时间： | 2020/5/9 0:00:00 |
A diagnosis and mesoscale analysis of an autumn severe rainstorm caused by typhoon trough |
| |
| WANG Lifang,ZHANG Xuerong,LIAO Yifan,PU Meijuan.A diagnosis and mesoscale analysis of an autumn severe rainstorm caused by typhoon trough[J].Scientia Meteorologica Sinica,2021,41(2):209-220. |
| |
| Authors: | WANG Lifang ZHANG Xuerong LIAO Yifan PU Meijuan |
| |
| Institution: | Jiading District Meteorological Bureau, Shanghai 201800,China;Key Laboratory of Transportation Meteorology, China Meteorological Administration, Nanjing 210009, China;Nanjing Joint Institute for Atmospheric Sciences, Nanjing 210009, China;Nanjing University of Information Science & Technology, Nanjing 210044, China; Nanjing University of Information Science & Technology, Nanjing 210044, China;Jiangsu Meteorological Observatory, Nanjing 210008, China |
| |
| Abstract: | Based on FNL reanalysis data,combined with intensive observation of automatic weather stations data, Doppler radar images,meteorological satellite data and numerical model prediction products, a typical autumn severe rainstorm caused by typhoon trough occurred in Yangtze River Delta region during 16-17 September 2018. Results show that it was caused by four mesoscale convective clouds triggered by sustained interaction of warm and cold air under the combined action of a remote typhoon trough, low-level jet and high-level through. The first stagerainstorm at the Yangtze riveroccur during the rapid enhancement of the third cloud, the heavy rainstorm area corresponds to the large TBB gradient area on the north side of the cloud, and the rain intensity increaserapidly as the cloud top temperature decreases.The slow eastward movement of the fourth cloud leads tothe second stage of rainstorm, and the accumulative effect of precipitation makes the rainfall amount further increases at the Yangtze river estuary.The surface mesoscale convergence line formed by northeasterly wind (northerly wind) and southeasterly wind (easterly wind) is the vital triggering mechanism, and the formation of cyclonic convergence center plays an important role in the increasing of rainfall.The formation of mesocyclone in doppler radar radial velocity field is about half an hour ahead of the increasing of heavy rain, which has important significance of forecast and warning.The sustained transportaction of water vapor and energy by lowlevel jet,inclined ascending branch and vertical circulation caused by the coupling of low and high level jet together with cold air intrusion,convective unstable stratification formed by dry-cold top and warm-wet bottom a benefit for the formation and maintenance of mesoscale storm clouds.The location of surface convergence line indicating the combination of cold and warm air is the key to the prediction of the rainstorm area.Special attention should paid to the effect of cold air activity on the triggering and increasing of rainstorm during similar autumn rainstorm caused by typhoon trough, timely modify model forecast conclusion based on real time observation. |
| |
| Keywords: | severe rainstorm typhoon trough cold air mesoscale clouds surface mesoscale convergence line |
| 本文献已被 CNKI 等数据库收录！ |
| 点击此处可从《气象科学》浏览原始摘要信息 |
| 点击此处可从《气象科学》下载免费的PDF全文 |
|
