基于扰动观测的EDA方法在CMA集合预报中的应用  

Application of Observation Perturbation-based EDA Method to CMA Ensemble Forecasting

作　　者：张涵斌 夏宇 曹亚杰 Zhang Hanbin;Xia Yu;Cao Yajie(Institute of Urban Meteorology,CMA,Beijing 100081;Tangshan Meteorological Bureau of Hebei,Tangshan 063000)

机构地区：[1]北京城市气象研究院,北京100089 [2]河北省唐山市气象局,唐山063000

出　　处：《应用气象学报》2025年第2期129-141,共13页Journal of Applied Meteorological Science

基　　金：中国气象局气象能力提升联合研究专项(22NLTSQ008);国家自然科学基金项目(U2242213)。

摘　　要：为发展中国气象局地球系统数值预报中心CMA-MESO模式对流尺度集合预报,基于CMA-MESO模式设计了观测扰动构建技术,并利用该技术发展集合资料同化(ensemble data assimilation,EDA)初值扰动方法。开展观测扰动敏感性试验、EDA方法在CMA-MESO对流尺度集合预报中的应用试验,分析观测扰动构建合理性及影响特征,并对比传统的动力降尺度方法与EDA方法的效果,结果表明:观测扰动可有效表征同化中来源于观测资料的不确定性特征;观测扰动主要影响CMA-MESO模式短时效预报效果,随时效延长逐渐耗散;EDA方法可有效形成对流尺度集合预报初值扰动,相对于传统的动力降尺度,该方法可显著减少初值扰动中来自背景场的扰动分量,并增加观测扰动分量体现观测的不确定性;强对流降水个例试验也表明,EDA方法可有效提高降水概率预报效果。To facilitate the development of convective-allowing ensemble forecasting technology based on the China Meteorological Administration's(CMA)Mesoscale Model(CMA-MESO),an observation perturbation scheme is designed.This scheme further enhances the ensemble data assimilation(EDA)method for generating initial conditions for CMA-MESO convective allowing ensemble forecasting system.The design and distinctive characteristics of the observation perturbations are studied,and several severe convective events are analyzed.It can be concluded that the observation perturbation scheme developed for CMA-MESO aligns with actual observation error characteristics,it can address uncertainties in the model initial analysis field stemming from observations,and multiple sets of observations generated can effectively represent uncertainties in observations.Observation sensitivity experiments are conducted to explore the impact characteristics of observation perturbations,and a typical convective weather event in Beijing is analyzed,results indicate that observation perturbations primarily affect the short-range forecast performance of CMA-MESO model,causing relatively small forecast perturbations.The growth of perturbations reaches saturation within a 12-24 h forecast range,while the energy of observational perturbations gradually dissipates as the forecast range extends.Observational uncertainties significantly influence the local convective characteristics and the spatiotemporal distribution of convective-related elements in short-range forecasts.Based on observation perturbations,an EDA initial value perturbation scheme is constructed,and a convective-scale ensemble forecasting experiment with a 3 km resolution is conducted over the North China.Results indicate that EDA scheme can effectively generate initial perturbations for convective-scale ensemble forecasting.Compared to traditional dynamic downscaling methods,EDA scheme minimizes uncertainties arising from large-scale background fields in convective-scale ensemble forecasting,

关 键 词：CMA-MESO模式 对流尺度集合预报 观测扰动 集合资料同化 

分 类 号：TP3[自动化与计算机技术—计算机科学与技术]