碩士 / 國防大學中正理工學院 / 應用物理研究所 / 96 / In this study, the brightness temperatures of 19, 22, and 37 GHz microwave channels from multiple satellites are matched with the radiosounde data to set up the retrieval equation for water vapor over the sea areas surrounding Taiwan. It is to monitor the amount of water vapor to improve the forecast ability for the heavy rainfall associated with the southwesterly flows, fronts, and yphoons affecting Taiwan.
The microwave brightness temperature (Tb) data of TMI, AMSR-E, SSM/I and the rawinsonde data over the Taiwan region during May - August of 2002 to 2006 have been collected and analyzed for this research. The Tetens’s equation is used to calculate the water vapor amount (V) from rawinsonde data. The V-Tb multi-channel linear regression equation is then set up by the statistic method and utilized to
estimate the water vapor amount over seas around Taiwan.
The results show that the water vapor amounts are underestimated at high values and overestimated at low values, comparing with those calculated from rawinsonde data. For TMI, the root-mean-square is 2.98 kg/m2 and the correlation coefficient is 0.959. For AMSR-E, they are respectively 3.48 kg/m2 and 0.934. For SSM/I, they are
respectively 2.46 kg/m2 and 0.954. Among the three types of satellite data, SSM/I, as a whole, has the best results in water vapor retrieval.
From case studies, the relation between the change of water vapor amounts and the evolution of precipitation associated with weather systems is found to be evident. Comparatively speaking, the water vapor amount and precipitation associated with the southwesterly flows have more obvious positive correlation for their spacial and
temporal evolution. For fronts and typhoons, the weather systems introduce more water vapor. As for the relation between the water vapor amount and precipitation, further research needs to be done in the future.
| Identifer | oai:union.ndltd.org:TW/096CCIT0504004 |
| Date | January 2008 |
| Creators | CHU CHIUNG-KUANG, 朱炯光 |
| Contributors | WANN JIN CHEN, 陳萬金 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 89 |
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