A two-stage inflation method in parameter estimation to compensate for constant parameter evolution in Community Earth System Model

作     者：Zheqi Shen Youmin Tang Zheqi Shen;Youmin Tang

作者机构：Key Laboratory of Marine Hazards Forecasting of Ministry of Natural ResourcesHohai UniversityNanjing 210098China College of OceanographyHohai UniversityNanjing 210098China Southern Marine Science and Engineering Laboratory(Zhuhai)Zhuhai 519080China Environmental Science and EngineeringUniversity of Northern British ColumbiaPrince George V2N 4Z9Canada 

出 版 物：《Acta Oceanologica Sinica》 (海洋学报（英文版）)

年 卷 期：2022年第41卷第2期

页      面：91-102页

核心收录：

学科分类：07[理学] 070601[理学-气象学] 0706[理学-大气科学] 

基　　金：The National Key Research and Development Program under contract No.2017YFA0604202 the Fundamental Research Funds for the Central Universities under contract No.B210201022 the National Natural Science Foundation of China under contract Nos 42176003,41690124,41806032 and 41806038 

主　　题：parameter estimation data assimilation inflation CESM EnKF 

摘      要：Parameter estimation is defined as the process to adjust or optimize the model parameter using observations.A long-term problem in ensemble-based parameter estimation methods is that the parameters are assumed to be constant during model *** assumption will cause underestimation of parameter ensemble spread,such that the parameter ensemble tends to collapse before an optimal solution is *** this work,a two-stage inflation method is developed for parameter estimation,which can address the collapse of parameter ensemble due to the constant evolution of *** the first stage,adaptive inflation is applied to the augmented states,in which the global scalar parameter is transformed to fields with spatial *** the second stage,extra multiplicative inflation is used to inflate the scalar parameter ensemble to compensate for constant parameter evolution,where the inflation factor is determined according to the spread growth ratio of model *** observation system simulation experiment with Community Earth System Model(CESM)shows that the second stage of the inflation scheme plays a crucial role in successful parameter *** proper multiplicative inflation factors,the parameter estimation can effectively reduce the parameter biases,providing more accurate analyses.