基于FY-4A卫星产品的2022年7月陕北一次暴雨天气过程分析  

Analyzing a Rainstorm Process in Northern Shaanxi in July2022 Based on FY-4A Satellite Products

作　　者：高星星 杜莉丽[1] 马晓华[1] Gao Xingxing;Du Lili;Ma Xiaohua(Shaanxi Meteorological Observatory,Xi’an 710014,China;Key Laboratory of Eco-Environment and Meteorology for the Qinling Mountains and Loess Plateau,CMA,Xi’an 710016,China)

机构地区：[1]陕西省气象台,西安710014 [2]中国气象局秦岭和黄土高原生态环境气象重点开放实验室,西安710016

出　　处：《气象与环境科学》2025年第2期94-103,共10页Meteorological and Environmental Sciences

基　　金：陕西省自然科学基础研究计划项目(2024JC-YBMS-217);秦岭和黄土高原生态环境气象重点实验室开放基金课题(2023G-2)。

摘　　要：利用FY-4A云图和定量化产品及地面气象站点观测、MICAPS、NCEP再分析和多普勒雷达资料,对2022年入汛以来陕北最强暴雨天气过程(7月11—12日)进行了分析。结果发现:降水主要集中在11日白天,08—20时累计雨量超过50 mm的站点有97个(占47%),超过100 mm的站点有11个,小时雨强大于20 mm的站点有60个。FY-4A降水估计也显示此次降水过程具有雨量大,极端性强,小时雨强大等特点,为强等级。高空槽配合低涡暖切是此次降水过程的主要影响系统,高空西风急流带的存在与维持使暴雨区400 hPa以上存在强FY-4A大气运动矢量辐散,叠加700 hPa低空急流左前侧强辐合区,使降水强度增强。强降水发生在涡旋云系中β及γ尺度对流云团的发展过程中,地面辐合线是涡旋云系中β及γ尺度对流云团的可能触发机制之一,FY-4A云参数进一步揭示了暴雨区存在强对流上升运动。FY-4A对流初生产品证实了层状云降水回波中镶嵌着对流单体,此次强降水与对流单体不断生成并东移产生“列车效应”有直接关系。暴雨前,来自南海的水汽输送已开始,10日16时FY-4A大气水汽总量最大值已达7 g/kg, 11日水汽输送不断加强,降水峰值时水汽通量中心最大值增加至8000 g·(cm·s·hPa)~(-1)。此次暴雨过程中,FY-4A对流层顶折叠深度最大的地区与位涡高中心对应较好,高空大值湿位涡下传,使高空干冷空气入侵低层,造成动力对流层顶折叠现象,是产生强对流天气的主要原因。To provide a scientific reference for the application of FY-4A cloud images and quantitative products in rainstorm weather monitoring and forecasting,using FY-4A cloud images and quantitative products,surface observations,MICAPS,NCEP reanalysis and Doppler radar data,this paper analyzes the heaviest rainstorm in Northern Shaanxi in July 11—12,2022 after into the flood season.The results show that the precipitation is mainly concentrated in the daytime of July 11.From 08:00 to 20:00 on the 11th,there were 97 stations with accumulated rainfall exceeding 50 mm(47%),11 stations with rainfall exceeding 100 mm,and 60 stations with hourly rainfall intensity exceeding 20 mm.The FY-4A precipitation estimates also show that the precipitation process was characterized by large rainfall amount,strong extremes and intense hourly rainfall,so it was a severe grade of rainstorm.The high trough and the warm shear of the low vortex were the main influence systems for this severe precipitation process.The existence and maintenance of the upper-air westerly jet belt caused strong FY-4A atmospheric motion vector divergence above 400 hPa in the rainstorm area,superposing the strong convergence area on the left front side of the low-level jet at 700 hPa and enhancing the precipitation intensity.Severe precipitation occurred in the developing process ofβandγscale convective cloud clusters in the vortex cloud system.The surface convergence line was one of the possible triggering mechanisms ofβandγscale convective cloud clusters in the vortex cloud system.The FY-4A cloud parameters further reveal the existence of strong convective upward motion in the rainstorm area.FY-4A convective initiation product confirms that convective cells were embedded in stratiform cloud precipitation echo,and this severe rainfall was directly related to the“train effect”caused by the continuous generation and eastward movement of convective cells.Before the occurrence of the rainstorm,there was water vapor transported from the South China Sea.At 16:0

关 键 词：FY-4A定量化产品 云图 对流初生 对流层顶折叠 陕北暴雨 

分 类 号：P458.121.1[天文地球—大气科学及气象学]