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

[AOS17-09] Interbasin effects on subdecadal climate changes relevant to global warming hiatus

*Takashi Mochizuki¹, Masahiro Watanabe², Masahide Kimoto², Yoshimitsu Chikamoto³ (1.Japan Agency for Marine-Earth Science and Technology, 2.The University of Tokyo, 3.Utah State University)

Keywords:interbasin effects, decadal climate variability, global climate model

Subdecadal modulation in the upper ocean heat content relevant to global warming hiatus is observed over the tropical Pacific in 2000s, in a different manner from other decades. On the subdecadal timescales, dynamical ocean response to the strong Pacific trade wind works to keep warm and cold tendencies in the western and eastern tropical Pacific Oceans, respectively. Consequently, it can contribute to slow down of global warming. Our decadal hindcasts with initialization insufficiently reproduce this subdecadal modulation a few years in advance, particularly due to low skill in hindcasting the strong trade wind observed in mid-2000s. Sensitivity experiments using a coupled climate model suggest that the strong trade wind can be largely contributed by high sea surface temperature over the tropical Atlantic Ocean in relation to the positive peak of the Atlantic Multidecadal Oscillation.