An evaluation study of the DRP-4-DVar approach with the Lorenz-96 model

作     者：JUANJUAN LIU~1,BIN WANG~(1*) QINGNONG XIAO~2,1 LASG,Institute of Atmospheric Physics, Beijing 100029,China 2 College of Marine Science,University of South Florida,St.Petersburg,FL 33701,USA 

会议日期：2012年

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

基　　金：the China Meteorological Administration for the R&D Special Fund for Public Welfare Industry(meteorology) (Grant No.GYHY(QX)200906009) the National High Technology Research and Development Program of China(863 Program.No.2010AA012304) the LASG free exploration fund 

摘      要：The study evaluates the performance of the dimension-reduced projection four-dimensional variational data assimilation (DRP-4-DVar) with the Lorenz-96 *** experiments over a period of 200 days have been *** results show that the DRP-4-DVar works *** generates an analysis equivalent to that of the Ensemble Kalman Filter(EnKF) if the synchronous observations are assimilated at the analysis time,while it produces more accurate analysis than the EnKF does when assimilating observations in an 18-h assimilation *** experiments also reveal that the impact of the tangent linear assumption for the Lorenz-96 model in the DRP-4-DVar over a 24-h or shorter assimilation window is ***,with a background error covariance matrix(B-matrix) that has a non-singular projection onto the ensemble space or is exphcitly flow-dependent,the DRP-4-DVar performs even better than with a B-matrix that has a singular projection or is not exphcitly flow-dependent.