基于ERA5资料的分析增量更新初始化对华南一次飑线过程预报的影响  

Impact of incremental analysis update initialization with ERA5 data on the forecasts of a squall line event in southern China

作　　者：高彦青 王晓峰 张蕾 张赟程[1,2] GAO Yanqing;WANG Xiaofeng;ZHANG Lei;ZHANG Yuncheng(Shanghai Ecological Forecasting and Remote Sensing Center,Shanghai 200030,China;Innovative Center of Regional High Resolution Numerical Weather Prediction,Shanghai 200030,China;Shanghai Typhoon Institute of China Meteorological Administration,Shanghai 200030,China)

机构地区：[1]上海市生态气象和卫星遥感中心,上海200030 [2]区域高分辨率数值预报创新中心,上海200030 [3]中国气象局上海台风研究所,上海200030

出　　处：《气象科学》2024年第6期1027-1037,共11页Journal of the Meteorological Sciences

基　　金：国家重点研发计划资助项目(2017YFC1501902);上海市科委自然科学基金资助项目(21ZR1457700)。

摘　　要：本文以2016年4月9—10日发生在华南地区的一次飑线过程为例,通过分析增量更新(Incremental Analysis Update, IAU)方法将全球模式再分析场ERA5信息融入高分辨率区域模式WRF中,研究了IAU初始化对此次飑线过程预报的影响。结果表明:(1)IAU初始化能有效减少粗分辨率全球再分析场引入到高分辨率区域模式所导致的不平衡,并保留区域模式背景场中的微物理信息,减少模式初始调整时间。(2)相比于直接利用ERA5冷启动的试验,采用IAU初始化模拟的飑线系统的线状结构和降水分布都更加接近观测。(3)进一步诊断表明,IAU初始化对此次飑线过程预报的改进主要与:保留区域模式背景场中的微物理信息导致冷池更快发展和通过修正环境场生成更加有利于飑线系统发展的层结条件有关。In this study,the impact of Incremental Analysis Update(IAU)initialization on the forecasts of a squall line event that occurred in southern China on 9-10 April 2016 was investigated.The ERA5 global reanalysis was incorporated into the high-resolution regional model WRF through the IAU method.Results show that:(1)IAU initialization can effectively reduce the imbalance caused by the introduction of low-resolution global reanalysis field into high-resolution regional model and retain the microphysical information in the background field of regional model,reducing the model spin-up time.(2)Compared with the cold start run initialized directly by the ERA5,the linear structure and precipitation distribution of the squall line system using IAU initialization are closer to the observations.(3)Further diagnostics indicate that the improvement of the squall line forecasts using IAU initialization is mainly related to the faster development of cold pool caused by retaining the microphysical information in the background field of regional model and more favorable stratification conditions for the development of squall line corrected by the IAU increment.

关 键 词：分析增量更新 高分辨率区域模式 飑线 ERA5 

分 类 号：P412.25[天文地球—大气科学及气象学]