[A-CG34] 地球規模環境変化の予測と検出

[ACG34-02] Extreme Sea Level Rise along Indian Ocean Coastline

★Invited Papers

*Swapna Panickal¹、P. Sreeraj^1,2、R. Krishnan¹、A. G. Nidheesh^1,3、N. Sandeep^1,2 (1.Indian Institute of Tropical Meteorology、2.Savitribai Phule Pune University、3.Université catholique de Louvain)

Anthropogenic sea-level rise poses challenges to coastal areas globally, combined influence of rising mean sea level (MSL) and storm-surges exacerbate extreme sea levels (ESL). Increasing ESL poses major challenge for densely populated coastlines. Yet, knowledge about past occurrences of ESL and its progression is lacking along Indian Ocean coastline. Combining high frequency tide-gauge data and satellite data, we show that ESL have become more frequent, longer-lasting and intense along Indian Ocean coastline. We detect a 2-3 fold increase in ESL occurrence, with higher risk especially along Arabian Sea coast and Islands. Utilizing IPCC MSL projections we show that Indian Ocean region will be exposed annually to the present-day 100-year ESL event by 2100, irrespective of the greenhouse gas emission pathways, and by 2050 under moderate-emission-mitigation-policy scenario. An attempt is also made to utilize AI/ML methods to predict the surges and ESL along the Indian Ocean coastline.