宜蘭與蘇澳東北季風時期之降水分析

An Analysis of Precipitation in Yilan and Su-ao during the Northeast Monsoon Period

楊淑明(Shu-Ming Yang)

《北市教大社教學報》 10期 (2011/12) Pp. 157-179

https://doi.org/10.7035/PSCTSCHP.201112.0157

摘要

蘭陽平原位於臺灣的東北角，為東北季風迎風區。每年十月到隔年二月，東北季風帶來水氣，使得本區降下豐沛的雨量。本研究主要以中央氣象局蘇澳和宜蘭2個地面氣象站之氣象數據，比較季節及東北季風時期的年際變化，探究兩地氣候之差異性。分析季節變化得到：蘇澳及宜蘭平均溫度全年無顯著差異；蘇澳站的降水量、降水日數、降水強度及平均風風速均高於宜蘭站；宜蘭平均相對濕度全年高於蘇澳。分析東北季風時期年際變化得知：蘇澳的降水量高於宜蘭，降水趨勢為下降，但不明顯；蘇澳降水日數高於宜蘭，兩地趨勢均為下降；蘇澳降水強度高於宜蘭，兩地降水強度趨勢微幅上升；兩地平均溫度趨勢均為上升，宜蘭上升輻度高於蘇澳；平均相對濕度在2000年以前，宜蘭大都高於蘇澳，但在2000年以後，則是蘇澳高於宜蘭，趨勢為下降；蘇澳平均風風速高於宜蘭，蘇澳趨勢微幅下降，宜蘭則是上升。

關鍵字

東北季風 ； 宜蘭 ； 蘇澳 ； 降水

並列摘要

Yilan is located in northeastern Taiwan, in the northeast monsoon zone. From October to February every year, moisture air brought by the northeast monsoon causes heavy rains in the area. This study analyzes observational data from two Central Weather Bureau weather stations in Su-ao and Yilan from 1982 to 2009, to compare their seasonal variation and their interannual variation during the northeast monsoon period; and in so doing, explore the climatic differences between the two stations. The results of the seasonal change show that no significant differences in mean annual temperature could be detected between Yilan and Su-ao. The Su-ao station's annual precipitation, precipitation days, precipitation intensity, and average wind speed were all higher than those of the Yilan station, while the average annual relative humidity was higher in Yilan than in Su-ao. The interannual variations in the northeast monsoon period are as follows: Su-ao's precipitation and number of precipitation days were higher than those of Yilan and showed a declining trend. The declining trend in precipitation and precipitation days was more obvious in Yilan than in Su-ao. The precipitation intensity was higher in Su-ao than in Yilan; both places displayed a slight trend of increased precipitation intensity and had a trend of rising temperatures, but Yilan's rate of increase was higher than Su-ao's. Both places' average relative humidity was gradually decreasing year by year. Before the year 2000, the relative humidity was higher in Yilan; after 2000, it was higher in Su-ao, showing that the trend of declining temperature is stronger in Yilan. The average wind speed was higher in Su-ao and showed a slight increasing trend, while the increasing trend in Yilan was more apparent.

並列關鍵字

Northeast monsoon ； Yilan ； Su-ao ； precipitation