崳山島(120.3E, 26.9N)，位於東海一個孤立的島嶼，在島上湖泊採集一沉積岩芯，發現數個從1930年代以來粗顆粒比例較高的沉積層。分析現地與衛星的雨量資料、再分析資料和颱風路徑資料，發現粗顆粒較多的沉積層，會產生在由梅雨鋒面系統和/或經過東海的颱風所造成的降雨異常強的年。此研究顯示沉積物紀錄有助於了解過去的氣候。 ;A significant poleward shift of tropical cyclones (TCs or typhoons) and TC-induced storm surge in the western North Pacific has occurred in recent decades. Here we use 64-year rainfall observations around Taiwan to provide an independent evidence of the shift. We show that, due to the island’s unique location relative to typhoon tracks, TC-induced rainfall trends are significantly rising west and north of the island but are insignificant east and southeast, caused by a preference in recent decades for TCs to veer more poleward. Analyses of large-scale fields indicate that the TCs’ poleward shift is caused by the weakening of the steering flow and western North Pacific subtropical high, which in turn is due to tropic-subtropical Indo-Pacific warming and a weakened monsoon, consistent with the expansion of the tropics due to climate change.
A sediment core collected in the bed of an isolated island lake in the East China Sea (120.3E, 26.9N) shows layers of high concentration of coarse deposition since the 1930’s. We show by analyzing in situ and satellite rainfall data, reanalysis data, and typhoon track data that the coarse-sediment layers were formed in years of anomalously strong precipitations contributed by passages of Mei-Yu fronts and/or typhoons across the East China Sea. Our study shows that sediment records can yield useful insight into the past climate.
