JpGU-AGU Joint Meeting 2017

講演情報

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[EE] 口頭発表

セッション記号 A (大気水圏科学) » A-OS 海洋科学・海洋環境

[A-OS17] [EE] Climate variations in the Atlantic Ocean and their representation in climate models

2017年5月24日(水) 09:00 〜 10:30 303 (国際会議場 3F)

コンビーナ:Ingo Richter(JAMSTEC Japan Agency for Marine-Earth Science and Technology)、Noel S Keenlyside(Geophysical Institute Bergen)、Thomas Spengler(University of Bergen)、Carlos R Mechoso(University of California Los Angeles)、座長:Richter Ingo(JAMSTEC Japan Agency for Marine-Earth Science and Technology)、座長:Mechoso Carlos(University of California Los Angeles)

09:00 〜 09:15

[AOS17-01] 熱帯大西洋の風-混合層-海面水温モード

*片岡 崇人1、渡部 雅浩1、木本 昌秀1 (1.東京大学大気海洋研究所)

The tropical Atlantic Ocean hosts a “meridional mode”, which is accompanied by cross-equatorial sea surface temperature (SST) anomaly gradient. It is thought that this mode is destabilized due to thermodynamic coupling between the wind speed, evaporation, and SST (WES feedback). Using a simple linear coupled model, we show that two additional ocean-atmosphere coupled feedback, which contribute to a cross-equatorial SST anomaly gradient, are possible in the tropical Atlantic, by taking mixed layer depth (MLD) variations into account. It is found that those feedback processes are stronger than the canonical WES feedback in our simple model framework. In the presence of damping effects, however, they exist either as a weakly unstable mode or a least damped mode. The SST and MLD structures in the simple model bear a resemblance to those of observed Atlantic meridional modes.