The Application Of NOAA/AMSU Data In Typhoon Study In North-West Pacific Ocean

Typhoon, as a disaster weather, has great relations with human activities. NOAA satellite data has been widely used in numerical weather forecasting due to its larger coverage with high temporal and spatial resolution. NOAA/AMSU data can be used to reveal the inner structure of tropical cyclone, which is very important to improve tropical cyclone forecasting.In this thesis, we introduce the status of typhoon study using satellite data and the principle and methods of atmospheric parameters retrieval, especially the principle of atmospheric temperature retrieval using BP neural network, which is used in SeaSpace TeraScan software at the satellite ground station in Ocean University of China.Based on the retrieved temperature profile from NOAA/AMSU data, typhoon"BILIS"and"KAEMI"in 2006, and typhoon"SEPAT","WIPHA"and"KROSA"in 2007 are selected in this thesis to analyze their structures, intensities and tracks. The typhoon structures showed by AMSU-B data (channel 150GHz) in this thesis are clearer and more intuitionistic compared with the MTSAT data. In AMSU-B data (channel 150GHz),the decrease of bright temperature means an increase of ice crystal above freezing layer because the main element absorbed in this channel is water vapor. Therefore, the bright temperature at 150GHz channel can be used as an indicator of the rain intensity. After the 5 typhoon cases processed, we analyze the relationship among temperature anomaly, typhoon intensity and warm core pressure and gives the quantitative relationship between typhoon intensity and warm core pressure, which can be used to study typhoon center's location. In this thesis, we found that typhoon's center is located at different height according to its intensity, which is different from the result of typhoon's center located at the height of 250hPa proposed by Liu et al.(2001). The typhoon track result is similar with JTWC's best track and the rms error in this thesis is smaller compared with the method of Liu et al.(2001). This study can be used as a reference to typhoon analysis using NOAA/AMSU data received at the satellite ground station in Ocean University of China.