集合敏感性分析法在一次典型梅雨锋暴雨中的应用  

Application of the method of ensemble sensitivity analysis in torrential rainfall of typical Meiyu front

作　　者：何斌[1] 宋刘明 任思婧 HE Bin;SONG Liuming;REN Sijing(Jiaxing Meteorological Bureau,Zhejiang Jiaxing 314050,China)

机构地区：[1]嘉兴市气象局,浙江嘉兴314050

出　　处：《气象科学》2025年第1期68-81,共14页Journal of the Meteorological Sciences

基　　金：中国气象局预报员专项(CMAYBY2020-051);浙江省气象局科技计划重点项目(2022ZD01)。

摘　　要：针对2017年6月11—12日影响浙江的一次典型梅雨锋暴雨过程,利用集合敏感性分析法研究了与暴雨落区、强度和相邻时次预报降水差异相关的短期和中期时段内主要环流系统的敏感性区域及其演变发展特征,验证了利用模式早期误差推算未来误差分布及强度演变的可能性。结果表明:(1)中期时段内与落区相关的主要敏感性天气系统为巴尔科什湖地区的低槽及其上游乌拉尔山地区的低涡,进入短期时段后,该低槽的发展将对其下游高压脊的发展和位置产生较明显的影响,进而影响阻塞高压前部深厚低涡系统的移动。高原西南部低槽的东移发展及副热带高压不同位置上的强度变化对落区也有显著影响;(2)对于强度而言,短期时段内敏感性信号较强,但进入中期时段后,信号则明显减弱,且主要集中在巴尔科什湖西北方的低涡附近。此外低纬度地区副热带高压与热带低压系统之间的相互作用及低压移动路径将对短期时段内副高西段的强度产生影响;(3)相邻时次降水预报差异的原因,在临近暴雨发生前与阻塞高压南侧、副高北侧的发展强度,高原东侧脊的强弱及高原中南部低压槽的发展有关,中期时段可以追溯到乌拉尔山低涡、巴尔克什湖低槽及高原西南侧的低槽附近,副高附近敏感性区域的演变则呈较明显的不连续特征;(4)前向集合回归的敏感性分析试验表明,正负回归区域与同时次上位势高度差的演变发展趋势存在较高的一致性,这表明早期模式误差可以预测未来系统误差的演变发展特征。By using the method of ensemble sensitivity analysis,this paper investigated the sensitivity areas of major circulation systems associated with the torrential rainfall of typical Meiyu front during 11-12 June 2017 over Zhejiang,and their evolution processes during short and medium ranges.Then,the possibility of prediction for error distribution and its evolution characteristics in the future by using early forecast errors were evaluated.Results are as follows:(1)it is showed that in medium range the major sensitive weather systems associated with torrential rainfall location are the lower trough nearby the Balkash Lake and the upstream vortex in the region of Ural Hill,while in short range the development of the lower trough has significant impact on the evolution of the downstream ridge,which further influences the movement of the deeper vortex in front of the blocking high.Also torrential rainfall location is substantially influenced by the eastward movement and development of the trough in the south-west Tibet Plateau and by the intensity changes in different parts of the subtropical high.It is also found that signal of sensitivity is strong in short range but weak in medium range,which mainly correlates with the vortex located in the upstream region of the Balkash Lake,so is the analysis of torrential rainfall intensity.In addition the interaction between the subtropical high and the tropical depression in lower latitude,and the depression s track have effects on the intensity in west side of the subtropical high.(2)The difference of forecasted precipitation between two adjacent runs are correlated with,near the time approaching torrential rainfall,the intensities of the blocking high and the subtropical high,the development of the low trough and ridge in the south-central and eastern Tibet Plateau,and in medium range,the vortex in the region of Ural Hill,the troughs in the Balkash Lake and the south-west Tibet Plateau.In addition,the evolution of the sensitivity areas in the subtropical high shows obvious fe

关 键 词：集合敏感性分析法 梅雨锋暴雨 经验正交分解 前向集合回归 

分 类 号：P458.121.1[天文地球—大气科学及气象学]