APPLICATION OF BDA SCHEME IN TYPHOON TRACK PREDICTION

The MM5, which is the PSU/NCAR mesoscale nonhydrostatic limited-area model, and itsadjoining modeling system are used in this paper. Taking T106 analysis data as background field the authorsgenerate an optimal initial condition of a typhoon by using two bogus data assimilation schemes, and conductsome numerical simulating experiments. The results of No.9608 typhoon (Gloria) show that the optimal initialfield have some dramatic improvements, such as inaccurate position of typhoon center, weaker typhooncirculation and incomplete inner structure of the typhoon, which are caused by shortage of data over the sea.Some improvements have been made in the track forecast. Through several comparing experiments, theinitialization optimized by BDA scheme is found to be more reasonable than GFDL scheme and its typhoon trackforecast is better.