An experimental analysis for the impact of 3D variation assimilation of satellite data on typhoon track simulation

A series of test simulations are performed to evaluate the impact of satellite-derived meteorological data on numericaltyphoon track prediction. Geostationary meteorological satellite (GMS5) and NOAAs TIROS operational verticalsounder (TOVS) observations are used in the experiments. A three-dimensional variational (3DVar) assimilationscheme is developed to assimilate the satellite data directly into the Penn StateNCAR nonhydrostatic meteorologi-cal model (MM5). Three-dimensional objective analysis fields based on the T213 results and conventional observa-tions are employed as the background fields of the initialization. The comparisons of the simulated typhoon tracksare carried out, which correspond respectively to assimilate different kinds of satellite data. It is found that, comparedwith the experiment without satellite data assimilation, the 3D-Var assimilation schemes lead to significant improve-ments on typhoon track prediction. Track errors reduce from approximately 25% at 24 h to approximately 30% at48 h for 3DVar assimilation experiments.