Analysis and Modeling of Low Visibility Environment Characterization in Western Taiwan and Off-Shore Islands

• Main Authors: CHIU,CHEN-YUAN, 邱振源
• Other Authors: LIAO,CHI-CHANG
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/66018301281523617276

碩士 === 國防大學理工學院 === 大氣科學碩士班 === 104 === According to civil air transport flight accidents disaggregated statistics, in 1999-2008 there were 37 flight accidents and 41% were related to the environment factors. Meanwhile, weather factors accounted for 38%. Based on the Aviation Safety Network statistics showing 2000-2014 of the fatal flight accidents and weather-related, in which the flight safety accident occurred due to low visibility accounted for 34%, Evident low visibility hugely affect flight safety. Taiwan belongs island climate with abundant moisture and the western region are mostly plain, terraced terrain, wherefore more conducive to the formation of dense fog. This resulted the effective control dense fog forming timing is extremely important for the west and the outer islands airports. In this study, surface meteorological observations data of the Central Weather Bureau (2009-2014) and Air Force (2009-2013) were used. Besides that, used statistics method summed up the regional, fogging characteristics and establishes the fogging of meteorological elements reference indicators. Statistics showed that station in western Taiwan fogging temperature range between 14°C-19°C. In addition, the relative humidity and the difference of the temperature and dew point respectively 95% above and 0-2.5°C. In terms of wind speed, Hsinchu region Winds weak during fogging but Chiayi and Tainan station up to 3ms-1-5ms-1 still have the chance of fogging. Statistics showed that Forecast rate is seriously low, represent each indicator is fogging sufficient conditions, but not necessary condition, therefore not suitable as a basis for forecasting. However, it still manages to understand the environmental characteristics by predicted value and provide forecasters reference. In order to develop low visibility forecast models for Taiwan, in this study, the most prone to dense fog in winter and spring, selection of Chiayi and Tainan low visibility cases were analyzed using high-resolution numerical WRF model. Reference from foreign scholars successfully simulated fog parameter and visibility equation were acted as a platform to simulate low visibility occurrence with the discovery of more than simulate regional as well as fogging occurs broadly in line with the actual time.