CMA-TYM混合En3DVar方案的设计和初步试验  

Development and Preliminary Test of CMA-TYM Hybrid En3DVar Scheme

作　　者：瞿安祥[1,2] 麻素红 张进[1,2] QU Anxiang;MA Suhong;ZHANG Jin(CMA Earth System Modeling and Prediction Centre(CEMC),Beijing 100081;State Key Laboratory of Severe Weather(LaSW),Beijing 100081)

机构地区：[1]中国气象局地球系统数值预报中心,北京100081 [2]灾害天气国家重点实验室,北京100081

出　　处：《气象》2022年第3期299-310,共12页Meteorological Monthly

基　　金：国家重点研发计划(2017YFC1502001);公益性行业(气象)科研专项(201406006)共同资助。

摘　　要：基于CMA-TYM的3DVar系统,发展了利用扩展控制变量引入流依赖背景误差协方差(集合扰动成员统计表达)的混合En3DVar同化方案。测试显示,单点台风中心气压数据同化会引起风场非对称增量形成,以及导致传统3DVar方案认为不相关的湿度增量出现。台风个例试验表明,混合En3DVar方案能提取台风内零散观测资料信息,并按实际台风动力特征和分布区域向四周传播,从而影响分析场中台风涡旋强度、结构。同时,与3DVar方案相比,混合En3DVar方案对提高台风路径、强度预报效果明显。In this paper,a hybrid variational data assimilation scheme by extended control variable,which introduces flow-dependent background error covariance(statistically described with ensemble forecast perturbations),has been developed based on the CMA-TYM 3 DVar system.Tests have shown that the assimilation of single-point typhoon central sea level pressure can cause the formation of asymmetric wind increments,and lead to the appearance of humidity increments that are considered irrelevant with pressure in the traditional 3 DVar scheme.Experiments of a typhoon case show that the hybrid En3 DVar scheme can effectively extract scattered observation data,and propagate it around according to the actual typhoon dynamic characteristics and distribution area,thereby it will change the structure and intensity of typhoon in the analysis field.At the same time,compared with the traditional 3 DVar scheme,the hybrid En3 DVar scheme has significant effect in improving the typhoon track and intensity forecast.

关 键 词：CMA-TYM 区域台风模式 混合变分资料同化 En3DVar 流依赖背景误差协方差 

分 类 号：P456[天文地球—大气科学及气象学]