JpGU-AGU Joint Meeting 2020

Presentation information

[E] Poster

A (Atmospheric and Hydrospheric Sciences ) » A-OS Ocean Sciences & Ocean Environment

[A-OS17] Climate variability and predictability on subseasonal to decadal timescales

convener:Takashi Mochizuki(Department of Earth and Planetary Sciences, Kyushu University), V Ramaswamy(NOAA GFDL), Yushi Morioka(Japan Agency for Marine-Earth Science and Technology)

[AOS17-P13] The Atlantic SST influences on the Pacific subdecadal variability

*Takashi Mochizuki1,2, Masahiro Watanabe3, Masahide Kimoto3 (1.Department of Earth and Planetary Sciences, Kyushu University, 2.Japan Agency for Marine-Earth Science and Technology, 3.Atmosphere and Ocean Research Institute, The University of Tokyo)

By performing two sets of partial data assimilation experiments using global climate model, we have demonstrated that sea surface temperature (SST) anomalies in the tropical and subtropical Atlantic Ocean contribute to forming high ocean temperature anomalies of the tropical Pacific in the early-2000s. Low SST over the tropical Atlantic changes the Walker circulation and the associated weakening of the Pacific trade wind raises the equatorial SST on the subdecadal timescales. At the same time, high SST anomaly is generated also in the off-equatorial North Pacific through deepening of the upper ocean thermocline due to an accompanying anti-cyclonic surface wind anomaly aloft. While the subtropical north Atlantic SST may help the subdecadal SST rising in the equatorial Pacific, the resultant SST anomalies show 1-year delay in phase transition and are hardly accompanied by the ocean thermocline deepening.