Attempt of coral-based reconstructions of tropical cyclone frequency in the Northwestern Pacific

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K01227
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Geography
• Research Institution: Gifu University
• Principal Investigator: Morimoto Maki 岐阜大学, 教育学部, 准教授 (30377999)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: サンゴ骨格年輪 / 高時間分解能 / 降水量 / 塩分 / 台風

Outline of Final Research Achievements

Annual banded corals have been used as high time-resolution proxy of past climate such as sea water temperature and salinity changes, so that coral skeletal records are potential archives of tropical cyclone activity. We improved a drilling and weighing method of subsampling for high precision and time-resolution intraseasonal reconstructions. At the Sekisei Lagoon of Ryukyu Archipelago in the Northwestern Pacific, daily and weekly instrumental records of sea surface temperature and salinity, and weekly coral isotope and Sr/Ca records from a core of living massive Porites colony were compared to cyclone and heavy rainfall events to test for detecting them.

Free Research Field

古気候学

Academic Significance and Societal Importance of the Research Achievements

本研究の特色は、地質試料を用いた古気候復元研究においてほとんどおこなわれたことのない、１つの季節内の気象現象、特に台風の検出を進めたことである。検出が可能になれば過去の台風復元に適用可能となり、現在と過去の台風や豪雨の大きさや頻度の比較、さらには気候システム研究の発展に繋がる。