台灣地區地磁場的相關研究最早在1981年，Yeh et al.,(1981)曾分析台灣地區地磁場的時空變化，發現地磁場有24、12及8小時這三個明顯的周期。台灣在2002年建立取樣率為一秒鐘一點的地磁觀測網。本研究主要針對台灣2009至2011三年的磁力資料作背景分析與討論，希望能對台灣的磁力背景更為了解。 在分析磁力資料中，發現恆春站的日變化量相較於台灣其他地區磁力站的日變化量大很多。為此瞭解原因於2012年9月及10月在恆春半島設置幾個二到三天的臨時觀測站，使用這些臨時站記錄的資料與恆春、台東、屏東地磁站做比較，初步結果認為在恆春半島由南往北日變化量大小逐漸遞減，同時為了瞭解日變化量較大的情況是否受緯度效應所致，分析中也將與台灣磁緯度相近的廣州與西班牙的磁力資料一起納入考量，結果顯示在廣州與西班牙磁力站的日變化量都比恆春的日變化量小。因此又於2013年1月在恆春半島設置4個經度相近緯度不同的臨時觀測站，探討在不同緯度各磁力站的日變化量差異。最後再與前人關於地磁海岸效應的研究進行比較與討論。本研究推測可能是因為恆春地區為半島，相較於台灣其他地磁站離海岸線較近，受到海岸效應影響較大，因此整個恆春半島的日變化量才會比台灣其他地磁站的日變化量大。 It has established a network of geomagnetic stations in Taiwan since 2002. This sampling rate is 1 sample per second. The earliest study of geomagnetic in Taiwan is Yeh et al., (1981), they has been observed geomagnetic field in Taiwan. They found that there are three periods 24, 12 and 8 hours in magnetic field. In this study, we also use the magnetic data of Taiwan from 2009 to 2011 analysis magnetic background and discussion. We expect to find out geomagnetic characteristics in Taiwan area. In addition, we find that the diurnal variation of the magnetic data in Hengchun station is much larger than other magnetic stations. In order to investigate why the diurnal variation is larger only in Taiwan, we add Guangzhou and Spain station whose magnetic latitude is similar to Taiwan and seek for the relationship between diurnal variation and magnetic latitude. The results show that the diurnal variation of Guangzhou and Spain station is smaller than the diurnal variation of the Hengchun station. In order to investigate the reason of the diurnal variation of the Hengchun station is much larger than other magnetic stations, the temporary stations had been set for two to three days recording in the Hengchun Peninsula on September and October in 2012. Then comparing these data with Hengchun, Taitung, Pingtung magnetic stations, we find the diurnal variation decrease gradually from south to north in the Hengchun Peninsula. Then, the temporary stations had been set again on January in 2013. Finally, we compared and discussed between our results and the previous studies about the geomagnetic coast effect. In this study, we presumably because the Hengchun is Peninsula region, the distance between the station and the coastline is nearer the other stations in Taiwan. So the diurnal variation of Hengchun Peninsula is larger than other stations in Taiwan.
