Initializing numerical weather prediction models with satellite-derived surface soil moisture: Data assimilation experiments with ECMWF's Integrated Forecast System and the TMI soil moisture data set

被引:138
作者
Drusch, M. [1 ]
机构
[1] European Ctr Medium Range Weather Forecasts, Reading, Berks, England
关键词
D O I
10.1029/2006JD007478
中图分类号
P4 [大气科学(气象学)];
学科分类号
0706 ; 070601 ;
摘要
Satellite-derived surface soil moisture data sets are readily available and have been used successfully in hydrological applications. In many operational numerical weather prediction systems the initial soil moisture conditions are analyzed from the modeled background and 2 m temperature and relative humidity. This approach has proven its efficiency to improve surface latent and sensible heat fluxes and consequently the forecast on large geographical domains. However, since soil moisture is not always related to screen level variables, model errors and uncertainties in the forcing data can accumulate in root zone soil moisture. Remotely sensed surface soil moisture is directly linked to the model's uppermost soil layer and therefore is a stronger constraint for the soil moisture analysis. For this study, three data assimilation experiments with the Integrated Forecast System ( IFS) of the European Centre for Medium-Range Weather Forecasts (ECMWF) have been performed for the 2-month period of June and July 2002: a control run based on the operational soil moisture analysis, an open loop run with freely evolving soil moisture, and an experimental run incorporating TMI (TRMM Microwave Imager) derived soil moisture over the southern United States. In this experimental run the satellite-derived soil moisture product is introduced through a nudging scheme using 6-hourly increments. Apart from the soil moisture analysis, the system setup reflects the operational forecast configuration including the atmospheric 4D-Var analysis. Soil moisture analyzed in the nudging experiment is the most accurate estimate when compared against in situ observations from the Oklahoma Mesonet. The corresponding forecast for 2 m temperature and relative humidity is almost as accurate as in the control experiment. Furthermore, it is shown that the soil moisture analysis influences local weather parameters including the planetary boundary layer height and cloud coverage.
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页数:14
相关论文
共 83 条
[1]  
[Anonymous], J APPL METEOROL
[2]   A global root-zone soil moisture analysis using simulated L-band brightness temperature in preparation for the hydros satellite mission [J].
Balsamo, G. ;
Mahfouf, J. -F. ;
Belair, S. ;
Deblonde, G. .
JOURNAL OF HYDROMETEOROLOGY, 2006, 7 (05) :1126-1146
[3]  
Bélair S, 2003, J HYDROMETEOROL, V4, P352, DOI 10.1175/1525-7541(2003)4<352:OIOTIL>2.0.CO
[4]  
2
[5]  
Beljaars ACM, 1996, MON WEATHER REV, V124, P362, DOI 10.1175/1520-0493(1996)124<0362:TAROTU>2.0.CO
[6]  
2
[7]  
BENJAMIN SG, 1986, MON WEATHER REV, V114, P307, DOI 10.1175/1520-0493(1986)114<0307:SEOSHA>2.0.CO
[8]  
2
[9]   Land-surface, boundary layer, and cloud-field coupling over the southwestern Amazon in ERA-40 [J].
Betts, AK ;
Viterbo, P .
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 2005, 110 (D14) :1-15
[10]   Soil moisture estimates from TRMM Microwave Imager observations over the Southern United States [J].
Bindlish, R ;
Jackson, TJ ;
Wood, E ;
Gao, HL ;
Starks, P ;
Bosch, D ;
Lakshmi, V .
REMOTE SENSING OF ENVIRONMENT, 2003, 85 (04) :507-515