混合層預測方程式之研究

• Main Authors: Wei-Lin Tseng, 曾威霖
• Other Authors: 張能復
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/46447202209172251282

碩士 === 國立臺灣大學 === 環境工程學研究所 === 93 === Mixing layer height (MH) is an important parameter for estimating the potential and concentrations of air pollution. It stands for the highest height of pollutants diffused upward. However, it is difficult to predict hourly MH precisely only by twice upper air measurements one day. Therefore, this study is based on thermodynamic equations and kinetic energy equations of turbulence in order to develop a series of MH prediction equations with more meteorological parameters. For understanding the workability and precision of these prediction equations, at first this study not only simulates the MHs of Taipei, Taichung, Kaoshung cities and Kao-ping area but also compares these results with meteorological models of CLAMET and TPAQM. And the comparisons show the high correlation (up to 0.8) between them. When the results of MH prediction equations model are compared with TPAQM, they get higher or lower values than TPAQM. The reasons are that Holzworth method can not concern about the warm and cold advections effect and the upper air data used do not get enough finer space-spread. About the results spread on the domain of my model, they show more different MH fields between the land and the sea around and get more sharply change of the land MHs on daytime than TPAQM. Secondly, it gets ventilation index and air pollution monitoring value together to find the relationship of them. The results of it presents that when serious air pollution episode happens, the ventilation index actually decreases and the pollutants are diffused weakly. At last, this study also takes the sensitivity analyses of input parameters for the prediction equations. The result shows that Bowen Ratio is the most influencing surface parameter for the development of the MH and the same with the potential temperature lapse rate in the layer above mixing height.