Application of direct assimilation of ATOVS microwave radiances to typhoon track prediction

In order to solve the difficult problem of typhoon track prediction due to the sparsity of conventionaldata over the tropical ocean, in this paper, the No. 0205 typhoon Rammasun of 4-6 July 2002 is studiedand an experiment of the typhoon track prediction is made with the direct use of the Advanced TIROS-NOperational Vertical Sounder (ATOVS) microwave radiance data in three-dimensional variational dataassimilation. The prediction result shows that the experiment with the ATOVS microwave radiance datacan not only successfully predict the observed fact that typhoon Rammasun moves northward and turnsright, but can also simulate the action of the fast movement of the typhoon, which cannot be simulated withonly conventional radiosonde data. The skill of the typhoon track prediction with the ATOVS microwaveradiance data is much better than that without the ATOVS data. The typhoon track prediction of theformer scheme is consistent in time and in location with the observation. The direct assimilation of ATOVSmicrowave radiance data is an available way to solve the problem of the sparse observation data over thetropical ocean, and has great potential in being applied to typhoon track prediction.