재분석 자료를 이용한 투발루 해역의 파랑, 해상풍의 장기 변동성 연구

Abstract

Recently, due to global climate change, sea levels have risen and coastal areas of South Pacific island countries are experiencing a crisis due to ocean climate change. Among them, the sea level in Tuvalu is rising by 5mm every year, and the risk of coastal disasters is increasing due to the very low altitude of about 4m and the increase in typhoon intensity. In order to respond to coastal disaster risks, analysis of related ocean climate variables is necessary, and for this, it is necessary to understand the state of the past ocean climate. Therefore, we would like to compare and analyze long-term changes in waves and sea surface winds, which are risk factors that can increase the risk of coastal disasters in Tuvalu. Accordingly, this study studied the long-term fluctuations and characteristics of waves and sea surface wind over past 30 years (1993 to 2022) based on ERA5 data, a re-analysis data targeting the sea around Funafuti, Tuvalu. Additionally, we performed an analysis of the impact of global-scale fluctuations on the fluctuations around the Funafuti, Tuvalu. In comparison with the global fluctuation, the sea surface wind in the vicinity of Funafuti showed an increase rate of 3 times, whereas the significant wave height and the wave period decreased by 0.5 and 1.6 times, respectively.