JpGU-AGU Joint Meeting 2017

講演情報

[EE] 口頭発表

セッション記号 A (大気水圏科学) » A-CG 大気水圏科学複合領域・一般

[A-CG43] [EE] 中緯度大気海洋相互作用

2017年5月20日(土) 13:45 〜 15:15 302 (国際会議場 3F)

コンビーナ:西井 和晃(三重大学大学院生物資源学研究科)、佐々木 克徳(Hokkaido University)、杉本 周作(東北大学大学院理学研究科)、大石 俊(東京大学大学院理学系研究科地球惑星科学専攻)、座長:西井 和晃(三重大学大学院生物資源学研究科)、座長:升永 竜介(東京大学先端科学技術研究センター)

13:45 〜 14:00

[ACG43-01] Inter-decadal modulations in the dynamic state of the Kuroshio Extension system: 1905-2016

★招待講演

*Bo Qiu1Shuiming Chen1Niklas Schneider1 (1.Department of Oceanography, University of Hawaii at Manoa)

キーワード:Kuroshio Extension, decadal variability, air-sea interaction

The Kuroshio Extension is an eastward-flowing, inertial jet in the subtropical western North Pacific after the Kuroshio separates from the coast of Japan. Being the extension of a wind-driven western boundary current, the KE has long been recognized as a turbulent current system rich in large-amplitude meanders and energetic mesoscale eddies. An important feature emerging from the past 25-yr satellite altimeter measurements is that the KE system exhibits clearly-defined decadal modulations between a stable and an unstable dynamic state. The decadally-modulating KE dynamic state exerts a great impact on the regional sea surface temperature, heat content and water mass properties. By clarifying the relationship and physical processes between the basin-scale wind forcing and the KE dynamic state over the altimeter era, we hindcast the KE dynamic state going back to 1905 with the use of ECMWF reanalysis wind stress product. It is found that the low-frequency KE variability modulated in the past century in connection with the mid-1920s, mid-1940s, and mid-1970s' climatic regime shifts in the Aleutian Low pressure system. In addition to the modulations in KE's response to the external wind forcing, the midlatitude ocean's feedback to the overlying atmosphere appeared to have differed within the epochs of the different 20th century regimes.