Japan Geoscience Union Meeting 2016

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International Session (Poster)

Symbol A (Atmospheric and Hydrospheric Sciences) » A-CG Complex & General

[A-CG06] Multi-scale ocean-atmosphere interaction in the tropics

Tue. May 24, 2016 5:15 PM - 6:30 PM Poster Hall (International Exhibition Hall HALL6)

Convener:*Tomoki Tozuka(Department of Earth and Planetary Science, Graduate School of Science, The University of Tokyo), Tangdong Qu(University of Hawaii at Manoa), Takuya Hasegawa(Japan Agency for Marine-Earth Science and Technology), Motoki Nagura(Japan Agency for Marine-Earth Science and Technology), Hiroki Tokinaga(Disaster Prevention Research Institute/Hakubi Center, Kyoto Univesity), Ayako Seiki(Japan Agency for Marine-Earth Science and Technology), Masamichi Ohba(Central Research Institute of Electric Power Industry (CRIEPI), Environmental Science Research Laboratory)

5:15 PM - 6:30 PM

[ACG06-P04] Variation of North Pacific subtropical gyre heat transport caused by the interior flow change

*Akira Nagano1, Shoichi Kizu2, Kimio Hanawa2, Dean Roemmich3 (1.Japan Agency for Marine-Earth Science and Technology, 2.Tohoku University, 3.Scripps Institution of Oceanography)

Keywords:North Pacific subtropical gyre, quasi-decadal variation, Tropical western Pacific warm pool

The subtropical gyre of the North Pacific consists of the northward flowing Kuroshio and the southward interior return flow. The variation of the net heat transport of the gyre is caused by the changes of the volume transport distribution with respect to temperature in the Kuroshio and the interior flow in addition to the gyre volume transport change. In this study, we focused on the volume transport distribution change in the interior flow, which can be taken into accounted by the volume transport-weighted temperature. By applying the altimeter-derived gravest empirical mode method to hydrographic and altimetric data from San Francisco to 30N, 145E via Honolulu, we estimated the geostrophic interior flow of the subtropical gyre between 1993 and 2012. Anomaly of the volume transport-weighted temperature from the seasonal mean cycle is caused by the change of the volume transport in a layer just above the isopycnal of 25.5sigma-theta. Peaks in a quasi-decadal variation of the volume transport-weighted temperature are found approximately one year before peaks of sea surface temperature in the tropical western Pacific warm pool region.