Current State of Ocean Acidification in Surface Waters of the Western Arctic Ocean from 2020 to 2022

Abstract

The aragonite saturation state (Ωarag) was determined for surface waters of the western Arctic Ocean over 3 years, from 2020 to 2022, to investigate the current state of ocean acidification and to assess the interannual variation in surface Ωarag. In the Chukchi marginal area (CMA), surface Ωarag ranged from 0.97 to 1.86 over 3 years, with an average value of 1.20, indicating near-saturated conditions with respect to aragonite. In the East Siberian marginal area (ESMA), surface Ωarag varied from 0.88 to 1.47, with an average value of 1.12, which was slightly lower than levels in the CMA. The ESMA experienced significant changes in environmental conditions and seawater carbonate chemistry during 2020？2022 compared to 2016？2018. These notable changes in the ESMA during 2020？2022 were attributed to the influence of the Beaufort Gyre. In contrast, the CMA showed little interannual variation in environmental conditions and seawater carbonate chemistry from 2016 to 2022. In the ESMA, the progression of ocean acidification depends on the Arctic Oscillation (AO) state; ocean acidification improves with a positive AO state and worsens when the AO state is negative.