Underway O2/Ar-estiment net community production across the Kuroshio Extension and impact on winter pCO2 drawdown

Abstract

[author abstract] Continuous and discrete O2 and O2/Ar measurements were sampled during a late winter transect across the Kuroshio Extension (~30ºN 146ºE to 41ºN 150ºE). Average saturation values for O2 and O2/Ar were found to be -4.4 ± 1.2% and -4.4 ± 1.4% respectively. Entrainment flux and air-sea gas exchange flux terms were accounted for in a ML mass balance. O2 and O2/Ar entrainment fluxes were found to be -93 ± 89 and -76 mmol C m-2 d-1. O2, and O2/Ar air-water fluxes were both equal to 70 ± 80 mmol C m-2 d-1. High variation obscured NCP estimation. Future studies within the KE must take into account entrainment fluxes to better constrain the mixed layer mass balance.