Atlantic impacts on subdecadal warming over the tropical Pacific in the 2000s

• Published in: Frontiers in Climate
• Main Authors: Takashi Mochizuki, Masahiro Watanabe
• Format: Article in Journal/Newspaper
• Language: English
• Published: Frontiers Media S.A. 2022
• Subjects: subdecadal variability; interbasin connection; walker circulation; ocean thermocline; tropical climate; partial data assimilation; Environmental sciences; GE1-350; Pacific; North Atlantic
• Online Access: https://doi.org/10.3389/fclim.2022.1040352; https://doaj.org/article/1668a3f09a0c48b3813ed7396fc8b128

IntroductionA subdecadal (i.e. , three-year running mean) variation over the tropical Pacific is very distinctively observed in the 2000s.Results and methodsHere, we have demonstrated that sea surface temperature (SST) anomalies in the tropical Atlantic contribute to forming high ocean-temperature anomalies in the tropical Pacific in the early 2000s by performing partial data assimilation of a global climate model. Low SSTs over the equatorial Atlantic change the Walker circulation, and the associated weakening of the Pacific trade winds raises the equatorial SST on subdecadal timescales. At the same time, a high SST anomaly is also generated in the off-equatorial North Pacific through deepening of the upper ocean thermocline due to an accompanying anticyclonic surface wind anomaly aloft. While the subtropical North Atlantic SSTs may help the subdecadal warming in the equatorial Pacific, the resultant SST anomalies show a one-year delay in the phase transition and are modestly accompanied by ocean thermocline deepening.DiscussionIt roughly follows the IMRaD format.