Flow-dependent background-error covariances for a convective-scale data assimilation system

被引:42
作者
Brousseau, Pierre
Berre, Loik
Bouttier, Francois
Desroziers, Gerald
机构
[1] CNRS, CNRM GAME, Toulouse, France
[2] Meteo France, Toulouse, France
关键词
assimilation ensemble; limited-area model; AROME-France; 3D-Var; LIMITED-AREA MODEL; STATISTICS; VARIANCES; FORMULATION; MESOSCALE;
D O I
10.1002/qj.920
中图分类号
P4 [大气科学(气象学)];
学科分类号
0706 ; 070601 ;
摘要
AROME-France is a convective-scale numerical weather prediction system which has been running operationally at Meteo-France since the end of 2008. It uses a 3D-Var assimilation scheme in order to determine its initial conditions. Static background-error covariances are calculated for the 3D-Var using differences between AROME forecasts from an ensemble data assimilation. In this study, the covariance calculation is generalized in order to estimate time-dependent background-error covariances. A six-member ensemble is shown to provide robust covariance estimates in the context of the considered homogeneous covariance formulation. There is significant day-to-day variability in the variances, autocorrelations, and cross-correlations of background errors. This variability is linked to the meteorological conditions over the AROME-France model domain. The benefits of using flow-dependent background-error covariances, instead of static ones, are shown using assimilation diagnostics and measures of forecast performance. Copyright (c) 2011 Royal Meteorological Societyw
引用
收藏
页码:310 / 322
页数:13
相关论文
共 34 条
[11]   Spectral and spatial localization of background-error correlations for data assimilation [J].
Buehner, Mark ;
Charron, Martin .
QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY, 2007, 133 (624) :615-630
[12]  
Daley R, 1991, ATMOSPERIC DATA ANAL
[13]   A wavelet approach to representing background error covariances in a limited-area model [J].
Deckmyn, A ;
Berre, L .
MONTHLY WEATHER REVIEW, 2005, 133 (05) :1279-1294
[14]  
Denis B, 2002, MON WEATHER REV, V130, P1812, DOI 10.1175/1520-0493(2002)130<1812:SDOTDA>2.0.CO
[15]  
2
[16]  
Derber J, 1999, TELLUS A, V51, P195, DOI 10.1034/j.1600-0870.1999.t01-2-00003.x
[18]  
Fisher M., 2003, P ECMWF SEM REC DEV, P45
[19]  
Houtekamer PL, 1998, MON WEATHER REV, V126, P796, DOI 10.1175/1520-0493(1998)126<0796:DAUAEK>2.0.CO
[20]  
2