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This research utilized the data collected eleven ground observation stations from four synoptic observation stations and nine automatic weather stations of Central Weather Bureau, and analyzed the features of temperature , rain and wind distribution in Yunlin , Chiayi and Tainan from 1997 to 2016 , which involves parameters such as average temperature, highest temperature, lowest temperature, temperature difference between day and night , average wind speed and average wind direction, rain amount and rain hour. The relationship with temperature, rain and control factors such as the altitude of observation station, the latitude of the station and wind speed were further explored as well.
It was discovered in the research that annual average temperature has a significant negative correlation to the altitude of observation station, meaning that temperature decreases with the increase of altitude; Though annual average temperature and the latitude of the station have a significant negative correlation, meaning that temperature decreases with the increase of latitude. It is no significant correlation between hourly average temperature and wind speed. However, the sea-land temperature difference is expressed in Tainan and Yujing, it is found that the hourly average sea-land temperature difference has a significant positive correlation with wind speed (p<0.05). The higher the sea-land temperature difference, the higher the wind speed; The valley temperature difference is represented by Alishan and Yujing. It was showed that the hourly average valley temperature difference was significantly negatively correlated with wind speed (p<0.05). The higher the valley temperature difference, the lower the wind speed. It means that the hourly temperature difference has an effect on the local wind system. However , under the influence of a weakly synoptic weather system , the local wind system such as sea-land breeze and valley breeze becomes more significant.
The distribution of average daily accumulated rainfall and daily rainfall hours in Yunlin , Chiayi and Tainan, it is mainly related to the terrain, geographical location, including upwind, leeward and surrounding terrain. Rainfall is generally higher in the typhoon season and autumn than in the other three seasons. The average accumulated rainfall in Yujing Station during the plum rain season and typhoon season is the highest among flat ground stations, which is related to the terrain of the river valley where it is located.
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