碩士 / 國防大學理工學院 / 大氣科學碩士班 / 103 / Low visibility fog have a significant impact on flight safety and shipping traffic. It is necessary to strengthen research the fog in Taiwan, sea fog forecast increase sensitivity, effectively grasp publish special reports of the timing of sea fog.
In this study, the main source of information is based on CWB. This study selected the hourly ground observation data during the past five years (2009-2013) the station near Taiwan Strait, characteristics of meteorological when sea fog occurred. Using statistical methods, synoptic method and model simulations to study. According to the statistical methods to understand the main of the distribution on fog time, found the most vulnerable areas of fog is Kinmen and Matsu station where is in the outlying islands. From station data, Kinmen station used the temperature difference with the dew point temperature (T-Td ≦ 1.5˚C), specific humidity (q> 0.01 kg / kg, q-qmavg> 0), wind speed (Ws ≦ 3m / s ) and rainfall ≦ 0.1mm to create prediction reference index for the establishment of the fog, the reference index of forecast is 50.4%, from February to May of forecast is 43.5%; Matsu station using the temperature difference with the dew point temperature (T-Td ≦ 1.5˚C), specific humidity (q> 0.008 kg / kg, q-qmavg> 0), wind speed (Ws ≦ 5m / s) and rainfall ≦ 0.1mm to create prediction reference index for the establishment of the fog, the reference index of forecast is 68.8%, from February to May of forecast is 31.7%. The results showed that it can’t only predict fog by using CWB station data. Through, it have to use numerical simulation to simulate sea fog.
Use case studies to understand the weather patterns of the fog and model simulations. First, use synoptic method to analyze weather map in April and May on 2013. Choose two cases to analyze the existing observational data. Reference past foreign scholars for sea fog simulation parameter setting and using simulation visibility equation to match the fog area is more reasonable. In addition, Kinmen and Matsu simulated by temperature and dew point temperature, relative humidity, wind speed and wind direction graph, can be found can be a good simulation of its trends.
Use two visibility equation to simulate every day in April and May by WRF model to check and statistics station observation data. dividing into Matsu and Kinmen to statistic. The correctness of simulation for observation is more than 73%. The ETS scores for SW99 visibility equation is slightly higher than FSL visibility equation. There is the overestimation for FSL visibility equation.
| Identifer | oai:union.ndltd.org:TW/103CCIT0022002 |
| Date | January 2015 |
| Creators | Shen, Cheng-Kuang, 沈正光 |
| Contributors | Liao, Chi-chang, 廖杞昌 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 86 |
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