The Xiamen Symposium on Marine Environmental Sciences

2027 Xiamen Symposium on Marine Environmental Sciences

January 12-15, 2027

Mechanisms Underlying the Absence of a Significant Ocean Carbon Sink Response to the 2023 Strong El Niño
ID:451 Oral Presentation

2027-01-13 14:30 (China Standard Time)

Session:Session 50 - Indo-Pacific Ocean Dynamics and Tropical Climate

Abstract
El Niño dominates the interannual variability of global air–sea CO₂ fluxes by suppressing CO₂ outgassing in the tropical Pacific. Using an ensemble of observation-based fCO₂ products and global ocean biogeochemical models (GOBMs), we find that in 2023, this suppression was weaker than during the previous major El Niño events of 1997–1998 and 2015–2016 (hereafter referred to as 1997/2015), despite comparable levels of surface warming. Focusing on a single GOBM, we show that during 1997/2015, strong warming coincided with a weakening of westerly winds and sharply reduced equatorial upwelling, causing pronounced outgassing suppression. In contrast, although warming in 2023 was similarly strong, the westerly wind anomaly and upwelling reduction were not as strong as during the previous El Niño events. Consequently, the non-thermal ocean pCO₂ decrease was smaller than in 1997/2015, while the thermal anomaly remained comparable, limiting the net pCO₂ response. In addition, the comparably high wind speeds facilitated high gas-exchange rates, which further prevented the suppression of CO₂ outgassing. These findings highlight the variability and complexity of the canonical El Niño–carbon coupling and call for improved theoretical, modeling, and observational constraints.
Speaker
Enhui Liao Shanghai Jiao Tong University

Author
Enhui Liao Shanghai Jiao Tong University

    Important Dates

    • Jan 30

      2026

      Session / Event proposals open

    • Mar 31

      2026

      Session / Event proposals close
      (Extended to April 7)

    • Apr 30

      2026

      Session acceptance notifications

    • Apr 30

      2026

      Abstract submissions & registration open

    • Jun 30

      2026

      Abstract submissions close
      (Extended to July 21)

    • Aug 31

      2026

      Abstract acceptance notifications

    • Sep 15

      2026

      Scientific program released

    • Oct 15

      2026

      Early bird registration closes

    • Jan 12–15

      2027

      XMAS 2027