500hPa zonal wind RMS error
0.92
2.36
0.30
0.36
0.43
0.74
4.04
3D-Var
LETKF
RMSE
Rawinsonde; climatology; uniform; random; ensemble spread; ÒidealÓ; 100%
ØWith 10% adaptive observations, the analysis accuracy is significantly improved for both 3D-Var and LETKF.
Ø 3D-Var is more sensitive to adaptive strategies than LETKF. Ensemble spread strategy gets best result among operational possible strategies
0.36
0.38
0.23
0.29
0.32
0.33
1.18