Construction of surface temperatures off the Kanto-Tokai districts over the past 108 years: Coastal warming and its influence on Japanese climate

2021 Fiscal Year Final Research Report

• Project/Area Number: 18K03737
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 17020:Atmospheric and hydrospheric sciences-related
• Research Institution: Tohoku University
• Principal Investigator: Sugimoto Shusaku 東北大学, 理学研究科, 准教授 (50547320)
• Project Period (FY): 2018-04-01 – 2022-03-31
• Keywords: 黒潮 / 大気海洋相互作用 / 大蛇行 / 地域気候 / 水蒸気 / 温暖化 / CMIP6 / 猛暑

Outline of Final Research Achievements

We collected oceanographic data from research institutes around the world and produced the past 100-year temperature time series for the inner region between Japan and the Kuroshio. As a result, we found that the inner region off the Kanto-Tokai district has warmed remarkably down to a depth of a few hundred meters. The world's most advanced satellite observation data and in-situ data from R/V Shinsei-maru revealed the coastal warming off the Kanto-Tokai district associated with the Kuroshio large meander and clarified that the warming is induced by the westward Kuroshio bifurcation. Numerical experiments using an atmospheric model revealed that the increased water vapor associated with the coastal warming in the Kanto-Tokai district causes a hotter and wetter summer climate in the Kanto region.

Free Research Field

海洋物理学

Academic Significance and Societal Importance of the Research Achievements

近年、地球温暖化に伴う海の変化が気候に及ぼす影響が懸念されている。本研究課題により、水蒸気を介して海洋（関東・東海沖沿岸域）が陸上気候（関東周辺の夏季気候）に影響を及ぼすことを世界で初めて明らかにした。近年、大気中の水蒸気は地球温暖化の進行とともに増加していることが指摘されており、今後、黒潮の流れ方によっては関東周辺は一層厳しい夏になることが懸念される。本研究成果は熱中症のリスクの低減や気候変動適応計画の策定に貢献するものである。