Assessment of austral autumn air–sea CO2 exchange in the Pacific sector of the Southern Ocean and dominant controlling factors

The factors that control the partial pressure of carbon dioxide ( p CO 2 ) in Pacific sector Southern Ocean were investigated April 2018, onboard icebreaker, ARAON. mean (± 1σ) sea surface was estimated to be 431 ± 6 μatm north Ross Sea (NRS), 403 18 Amundsen–Bellingshausen (ABS), and 426 16 western Antarctic Peninsula Weddell (WAP/WS). controlling for NRS appeared meridionally different based on southern boundary Circumpolar Current (SB; ~62.5°S Sea). exhibited a strong correlation with salinity difference between O /Ar (ΔO /Ar) values sample air-saturated water south SB, respectively. ABS WAP/WS displayed salinity. Furthermore, ΔO ice formation appear dominant Confluence Zone (CZ) northern parts WAP/WS. air–sea fluxes (positive negative indicate source sink atmospheric , respectively) range from 3.1 18.8 mmol m −2 d −1 NRS, −12.7 17.3 ABS, −59.4 140.8 In addition, biology-driven large variations flux observed CZ. Our results are most recent observation data acquired austral autumn Ocean.