The Application of AMSU Data for the Enviromental Water Vapor Transportation around the Tropical Cyclone

Large-scale environmental vapor flux plays a very important role in the development of tropical cyclones. A regression method was developed to get the relationship between radiances measured by the Advanced Microwave sounding unit (AMSU) and water vapor content. With this formula, we get the water vapor content in the upper, middle and lower troposphere, which retrieveled by channels 183.3 plusmn 1 GHz, 183.3 plusmn 3 GHz and 183.3 plusmn 7 GHz brightness temperatures respectively. Then, we illustrate the Typhoon Bilis (0604) to analyse the distributing and evolvement of the surrounding water vapor. By this exponentially algorithm, there are great water vapor transportations as indicated by the water vapor channel brightness temperatures. And it shows the importance of the environmental water vapor in the development of tropical cyclones.