[A-CG35] 熱帯におけるマルチスケール大気海洋相互作用

[ACG35-09] 2010年代以降の急激な地球温暖化と熱帯太平洋十年規模変動の役割

*小坂 優¹、謝 尚平² (1.東京大学先端科学技術研究センター、2.カリフォルニア大学スクリプス海洋研究所)

キーワード：熱帯太平洋十年規模変動、地球温暖化、要因分析

Observational records feature a jump of the global mean surface temperature in the mid-2010s after the so-called “hiatus” of global warming, in association with the 2015/16 strong El Niño event. Since then, the temperature has remained high despite some La Niña events, and the top seven of annual global mean surface temperature in instrumental records are occupied by the recent seven years. Our coupled model pacemaker simulation, where the tropical Pacific SST anomalies are forced to follow the observational counterparts, reproduces this post-hiatus global warming well. The Pacific Decadal Variability shifted from the negative peak in the late hiatus period to the neutral state in the post-hiatus period, contributing to the rapid global warming. Atmospheric model experiments suggest that, in addition to direct influence from the tropical SST anomalies, tropical Pacific-induced extratropical SST and sea ice anomalies contributed comparably to the Northern Hemisphere atmospheric circulation anomalies during the post-hiatus period.