CMA-BJ模式对“23·7”极端强降水过程预报性能分析  

Evaluating the CMA-BJ model performance in predicting the July 2023 extreme heavy rainstorm over North China

作　　者：郭淳薇 仲跻芹 赵秀娟 张亦洲 程思宇 张帅 薛一迪 李玉焕 卢冰 黄诚诚 徐敬 GUO Chunwei;ZHONG Jiqin;ZHAO Xiujuan;ZHANG Yizhou;CHENG Siyu;ZHANG Shuai;XUE Yidi;LI Yuhuan;LU Bing;HUANG Chengcheng;XU Jing(Institute of Urban Meteorology,China Meteorological Administration,Beijing 100089,China)

机构地区：[1]北京城市气象研究院,北京100089

出　　处：《气象学报》2025年第2期304-319,共16页Acta Meteorologica Sinica

基　　金：国家重点研发计划课题(2021YFC3000901);国家自然科学基金气象联合基金(U2442204);北京市气象局科技项目青年基金(BMBKJ202302003)。

摘　　要：由于台风“杜苏芮”登陆北上减弱为低压后,受到“高压坝”阻挡停滞移动缓慢,2023年7月29日至8月2日,京津冀地区出现一次极端强降水过程,该次降水过程持续时间长、单站累计降水量突破历史极值,造成了严重的洪涝灾害。基于降水观测资料,全面评估了华北中尺度数值预报系统(CMA-BJ v2.0)对此次降水过程的预报性能和表现。使用资料包括京津冀地区站点降水观测、欧洲中期天气预报中心(ECMWF)、美国国家环境预报中心(NCEP)GFS(Global Forecast System)全球预报场。结果表明:CMA-BJ v2.0预报与观测的累计降水空间量分布特征整体一致,降水时段一致,雨量整体偏大,其中D02预报与观测最为接近。使用GFS全球场进行驱动时,雨带整体南移,降水高值区出现在河北省中、南部,与观测偏差较大,使用ECMWF驱动预报更接近观测;多次循环同化策略相比于冷启动不同化、冷启动单次同化方式,风速不断增大,带来大量水汽,降水的分布与观 测更加吻合;边界层参数化方案的选择对风场的预报有一定的影响,进而影响降水的分布和量级,此次降水过程中 YSU( Yonsei University scheme)方案较 ACM2(Asymmetric Convective Model)、Boulac(Bougeault-Lacarrere scheme)方案预报效果更好。Typhoon"Doksuri"weakened to a low-pressure system in the north,and it was blocked by a high-pressure ridge and moved slowly.From 29 July to 2 August 2023,an extremely heavy rainstorm event occurred in Beijing-Tianjin-Hebei region and lasted for a long time.Record-breaking cumulative precipitation occurred at individual stations,causing severe flooding.Based on precipitation observations,this paper comprehensively evaluates the CMA-BJ v2.0 performance on the simulation of the precipitation event.Spatial distribution characteristics of the cumulative precipitation and precipitation period in the CMA-BJ v2.0 forecast are consistent with observations.The rainfall overall was overestimated,and the D02 forecast is closest to the observation.When the GFS(Global Foercast System)global background field is used,the rain belt moved further south,and high precipitation area appeared in central and southern Hebei province,greatly deviating from the observations.In contrast,the ECMWF-driven forecast is closer to the observation.Compared to results of the cold-start run and single-time assimilation run,wind speed in the multipleassimilation run keeps increasing,and brings in a large amount of water vapor.As a result,the distribution of precipitation is more consistent with observations.The choice of boundary layer parameterization scheme has certain impacts on the forecast of wind field,and affects the distribution and magnitude of precipitation.The YSU(Yonsei University)scheme performs better than the ACM2(Asymmetric Convective Model)and Boulac(Bougeault-Lacarrere)schemes in the simulation of this precipitation event.

关 键 词：极端强降水过程 CMA-BJ 大尺度背景场 同化 物理过程 

分 类 号：P435[天文地球—大气科学及气象学]