Abstract Bimodal dynamic states of the Kuroshio Extension (KE)—stable and unstable—have been extensively studied due to the KE’s critical role in climate variability. However, its influence on sea‐air CO2 flux remains uncertain, despite the KE region being recognized as one of the principal oceanic carbon sinks globally. Utilizing observational data and a state‐of‐the‐art global ocean biogeochemistry model that assimilates both physical and biogeochemical observations, we reveal that the KE bimodal states substantially modulate sea‐air CO2 flux. During the KE stable state, oceanic CO2 uptake intensifies due to lateral divergence of dissolved inorganic carbon (DIC) within the mixed layer and increased surface wind speed. The DIC divergence results from the northward displacement of the DIC front associated with the northward‐shifted KE jet. Observations reveal that mesoscale warming contributes to accelerated surface winds, a feature not captured by the model.
Observations from the Little Bunker
Last updated: August 18, 2025 04:13 PM
Atmospheric CO₂
425.4 ppm
+18.4
ppm/year
Atmospheric CH₄
1934.91 ppb
+9.11
ppb/year
Global Temperature
+1.48 °C
Peak: +1.73°C
World Population
8.1 billion
+67
million/year