摘要
为开展全球高分辨率数值天气预报和模拟,以中国气象局现有业务模式GRAPES为基础,发展了水平0.1°×0.1°分辨率的球面准均匀阴阳网格全球非静力模式GRAPES;Y。选择2020年7月6—8日出现在安徽南部的一次强降水个例作为研究对象,利用0.1°×0.1°分辨率GRAPES;Y模拟结果,结合FNL 0.25°×0.25°再分析资料、逐时降水融合产品和雷达资料,对模拟结果进行分析和检验。结果表明,此次强降水受高空槽、低涡切变线、低空急流的共同影响,由稳定梅雨锋上的不断东移的中尺度对流系统形成,模拟的大尺度环流系统的位置及强度与FNL 0.25°×0.25°再分析结果基本一致。模式较好模拟出24 h累积降水雨带的大值区位置和走向,但强降水强度和弱降水雨带分布有差异,强降水区维持明显的低层水汽辐合以及西南水汽通道。模拟结果显示,强降水和对流中心对应异常强的500 hPa假相当位温的大值区,其位置的南北摆动保持一致,表现在剖面图上为梅雨锋对流区的深厚对流中性区和锋区南北为对流不稳定区,锋区的850 hPa以下的边界层内表现为一致的对流不稳定。
For global high-resolution numerical weather prediction,based on the GRAPES developed by China Meteorological Administration,an updated version,the GRAPES;Y,has been developed on the Yin-Yang grid,which is now available at 0.1°×0.1°resolution.The"violent Meiyu"process that took place in the middle and lower reaches of Yangtze River during 6—8 July 2020 is selected as the object of simulation.A case of Meiyu severe rainfall in south of Anhui Province is analyzed by using the 0.1°×0.1°model outputs,FNL 0.25°×0.25°reanalysis data and hourly rainfall observation and weather radar reflectivity.Results show that the severe rainfall was a direct result of eastward moving mesoscale convective systems under the joint action of upper trough,low vortex shear lines and low-level jets.The simulated position and intensity of the large-scale systems is comparable with the FNL 0.25°×0.25°reanalysis results.The orientation and position of the 24 h precipitation are well described in the simulation although distinction on severe-rainfall intensity and weak-rainfall region is found.Persistent severe rainfall depends on the low-level vapor convergence and smooth vapor transport.The severe rainfall is in accordance with the largeθ;region at 500 hPa,showing up as convectively neutral zone.Except the instable below 850 hPa in frontal zone,convectively instable layer appears at both south and north of the front.
作者
焦涵
赵益帆
常飞
彭新东
JIAO Han;ZHAO Yifan;CHANG Fei;PENG Xindong(Disaster Prevention Research Institute,Kyoto University,Kyoto 611-0011,Japan;State Key Laboratory of Severe Weather,Chinese Academy of Meteorological Sciences,Beijing 100081;Gansu Branch,CAAC Northwest Regional Administration,Lanzhou 730087)
出处
《气象》
CSCD
北大核心
2021年第11期1359-1368,共10页
Meteorological Monthly
基金
国家重点研发计划(2018YFC1507005)资助。
关键词
阴阳网格
非静力模式
梅雨锋
对流
降水
Yin-Yang grid
non-hydrostatic model
Meiyu front
convection
precipitation
