The authors thank the three anonymous reviewers for their valuable comments. This study was supported by the Korea Meteorological Administration Research and Development Program under Grant CATER 2012-2030.
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The domain is centered in the typhoon region rather than near the Korean Peninsula because the experiments were conducted for the 2008 typhoon season, when the international field campaign T-PARC was conducted.
The WRFDA system includes four-dimensional variational data analysis (4DVAR; Huang et al. 2009) and hybrid systems (Wang et al. 2008), as well as the 3DVAR system. Because of the complex characteristics of the adjoint-derived observation impact estimation, we adopted 3DVAR as an analysis system. It does not consider the time variation of state. First guess at appropriate time (FGAT) was not used in this study.