Theoretical and numerical study on a western boundary current extension jet as part of constructing ocean circulation theory

2023 Fiscal Year Final Research Report

• Project/Area Number: 19K03962
• 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: Hokkaido University
• Principal Investigator: KUBOKAWA Atsushi 北海道大学, 地球環境科学研究院, 名誉教授 (00178039)
• Project Period (FY): 2019-04-01 – 2024-03-31
• Keywords: 海洋循環 / 東向きジェット / 西岸境界流続流 / 再循環

Outline of Final Research Achievements

After the Kuroshio leaves the Japanese coast, it forms the Kuroshio Extension jet, which extends eastward for a long distance. This study theoretically and numerically investigated the meridional structure of the oceanic currents in areas where such western boundary current extension jet exists, the latitude of the extension jet, and how far the jet extends, using simple models. As a result, it has been found that if the large-scale southward flow has no influence, the latitude and meridional structure of the jet can be roughly determined by the large-scale circulation field and the jet strength, and the jet length is strongly affected by the background large-scale southward flow.

Free Research Field

海洋物理学、地球流体力学

Academic Significance and Societal Importance of the Research Achievements

西岸境界流続流ジェットの緯度や長さの大規模な海洋循環との関係を明らかにすることは、海盆スケールの海洋循環を理解するために必要である。また、西岸境界流続流域は海洋から大気への熱放出の大きなところであり、その大規模な風の場への応答を理解することは、気候変化の予測と理解にも重要であると考えられる。