Application Of NOAA/AMSU Temperature Profile Data In The Study Of Typhoon Structure And Track

Typhoon is kind of tropical cyclone with certain intensity which happens in thePacific Ocean. It is a typical severe disaster, which can result in a huge loss ofpeople’s lives and properties. The Advanced Microwave Sounding Unit (AMSU) waslaunched aboard the NOAA weather satellite by the National Oceanic andAtmospheric Administration (NOAA), which has more detection channels, higherspatial resolution and improved radiometer detection accuracy. Owing to themicrowave radiation can penetrate clouds, it’s very appropriate for us to do researchon typhoon’s internal characteristic parameters in use of the AMSU data, which canreveal the characteristic changes of typhoon internal structure. And these studies mayprovide certain value in improving typhoon numerical prediction.In this thesis, the status and progress of the typhoon research work are described.Then we present how to retrieve the atmospheric temperature and humidityparameters from NOAA/AMSU data using BP neural network and SeaSpaceTeraScan software, which is carried out at the satellite earth stations in OceanUniversity of China. On this basis, we select four typhoons happened in the year2006-2011, including Bilis, Raccoon, Morakot and Muifa, to study their structuresand track characteristics. In typhoon structure studying, the AMSU-B brightnesstemperature (channel89GHZ) images are used to present the temperaturecharacteristics and rainfall features, especially for the warm core structure and spiralrain band which form in the developing process of typhoon. In typhoon track analysis,we first describe the relations between warm core structure and typhoon intensity.Using AMSU-A temperature data that corresponds to different height troposphereatmosphere which is closely related to the typhoon intensity, we locate the position oftyphoon warm core and obtain the typhoon track. Furthermore, MTSAT infrared cloud images are also utilized to locate the typhoon center. In order to analyze theeffect of typhoon track study, we use JTWC typhoon best track to make comparisonwith AMSU-A and MTSAT methods.The conclusions of this thesis are as follows:(1) The warm core structure and thespiral rain band of typhoon can be well and clearly showed by AMSU-B (channel89GHZ). Compared with MTSAT infrared image, the symmetry of structure showed byAMSU-B89GHZ brightness temperature images is more intuitive.(2) With typhoonintensity increasing, the warm core position is changing. The result shows that thestronger is typhoon, the bigger is warm core pressure, and the lower is the height ofwarm core.(3) Using AMSU temperature profile data to locate warm core of typhoon,the moving track can be efficiently estimated and is similar to JTWC typhoon besttrack. According to JTWC typhoon best track, the RMS error in this thesis is smallerthan that of MTSAT infrared cloud images locating method. The results shows thateyewall vertical structure may be highly tilted and the vertical wind shear profile ismuch more complex than generally expected in the process of typhoon moving.