研究顯示地震期間地殼形變可能伴生電荷而產生垂直地表之大氣電場，進而引發大氣閃電之發生。本論文分析台灣地區1994-2002年閃電數量及強度的時間與空間分布以瞭解大氣電場的變化趨勢。分別就季節變化、日變化及太陽活動變化三個部分進行探討，結果發現閃電主要發生在夏季及秋季的午後，且空間分布集中在台灣西部及西南部。地震方面，探討發生於1999年9月21日之集集地震期間大氣放電現象，發現於車龍埔斷層附近震前之閃電次數多於其震後。為了進一步驗證此趨勢，統計分析1993-2002十年期間台灣地區356個發生於269天期間ML≧5.0地震震央附近閃電次數及強度分布，並分別探討72個陸上地震及197個海上地震，以瞭解閃電和地震發生位置之關係。結果顯示，陸上地震震前閃電次數明顯多於震後，但海上地震則是地震前後閃電次數相當。此一現象說明地震期間之閃電發生與地表電導率有關。 The crust deformation could activate charges, which causes the atmospheric electric field and might result in lightning. In this thesis, seasonal, daily, and solar activity variations of the lightning activities in Taiwan during the period 1994-2002 are investigated. It is found that lightning often occurs in the afternoon of summer and fall seasons around the west and southwest of Taiwan. A case study shows that lightning activities near the fault zone significantly enhanced 2-7 days prior to the Chi-Chi earthquake occurred on 20 September 1999, 1747UT. A statistical investigation of lightning activities 15 days before and after 269 ML≧5.0 earthquake days occurred in Taiwan during 1993-2002 are carried out. Lightning frequencies and intensity are isolated within 50km x 50km area of each epicenter 15 days before and after the earthquakes and stacked for the overall 269 earthquakes, the 197 sea earthquakes, and the 72 land earthquakes. Results show that the stacked sum of the lightning frequencies before the earthquakes is greater than that of after for the land earthquakes. However, for the sea earthquakes, the stacked sum is nearly equal before and after the earthquakes. The difference between the land and sea earthquakes suggests the conductivity to be important.
