Investigation of the Air-sea CO2 Uptake at the KEO Buoy in the NW Pacific Kuroshio Extension Recirculation Gyre

The Kuroshio Extension Observatory (KEO) is a moored buoy, located in the Western North Pacific measuring meteorological and upper ocean conditions. These long-term observations track large exchanges of CO2 and heat at the air-sea interface typical of Western Boundary Currents like the Kuroshio. This study focuses on understanding the drivers of the partial pressure of CO2 (pCO2) in seawater and CO2 flux at KEO. We use established methods to separate the effects of temperature and other drivers, like biology and upwelling of CO2-rich water, on the seasonal cycle of seawater pCO2. We find that the seasonal cycle of CO2 uptake is primarily influenced by changes in seawater pCO2. The thermodynamic effect on the seasonality of seawater pCO2 is more influential than other drivers, such as seasonal biological production. By characterizing the drivers of ocean CO2 variability, we can better understand CO2 uptake and respond to the potential impacts of ocean acidification on marine life as the ocean continues to warm and absorb CO2.