NUMERICAL EXPERIMENTS ON MULTI-LEVEL STATISTICAL ESTIMATION OF DYNAMIC BALANCE CONSTRAINTS IN GRAPES-3DVAR  

作　　者：王瑞春 龚建东 张林 薛谌彬 

机构地区：[1]School of Atmospheric Science, Nanjing University of Information Science & Technology [2]National Meteorological Center [3]Jiangxi Meteorological Observatory

出　　处：《Journal of Tropical Meteorology》2015年第4期417-427,共11页热带气象学报（英文版）

基　　金：China Special Fund for Meteorological Research in the Public Interest(GYHY201106008,GYHY201506003);China Meteorological Administration Special Fund for the Development of Numerical Weather Prediction(GRAPES);Research Innovation Program for College Graduates of Jiangsu Province(CXZZ13_0497)

摘　　要：This paper further explores the estimating and expressing of dynamic balance constraints using statistical methods in GRAPES-3DVAR(Version GM). Unlike the single-level scheme which only considers the coupling between mass and wind at one level, the multi-level scheme considers the coupling between their vertical profiles and calculates the balanced mass field at each layer using the rotational wind at all model levels. A reformed ridge regression method is used in the new scheme to avoid the multicollinearity problem and reduce the noises caused by unbalanced mesoscale disturbances. The results of numerical experiments show that the new scheme can get more reasonable vertical mass field, reduce the magnitude of the adjustment by the initialization, and improve the potential temperature analysis performance. Furthermore, the results of forecast verification in January(winter) and July(summer) both confirm that the new scheme can significantly improve the temperature forecast accuracy and bring slight positive effects to the pressure and wind forecast.This paper further explores the estimating and expressing of dynamic balance constraints using statistical methods in GRAPES-3DVAR （Version GM）. Unlike the single-level scheme which only considers the coupling be- tween mass and wind at one level, the multi-level scheme considers the coupling between their vertical profiles and cal- culates the balanced mass field at each layer using the rotational wind at all model levels. A reformed ridge regression method is used in the new scheme to avoid the multicollinearity problem and reduce the noises caused by unbalanced mesoscale disturbances. The results of numerical experiments show that the new scheme can get more reasonable verti- cal mass field, reduce the magnitude of the adjustment by the initialization, and improve the potential temperature anal- ysis performance. Furthermore, the results of forecast verification in January （winter） and July （summer） both confirm that the new scheme can significantly improve the temperature forecast accuracy and bring slight positive effects to the pressure and wind forecast.

关 键 词：dynamic balance constraints 3DVAR GRAPES numerical experiment 

分 类 号：P456[天文地球—大气科学及气象学]