Abstract. Rapid climate warming and sea-ice loss have induced major changes in the sea surface partial pressure of CO2 (𝑝CO2). However, the long-term trends in the western Arctic Ocean are unknown. Here we show that in 1994–2017, summer 𝑝CO2 in the Canada Basin increased at twice the rate of atmospheric increase.
Warming and ice loss in the basin have strengthened the 𝑝CO2 seasonal amplitude, resulting in the rapid decadal increase. Consequently, the summer air–sea CO2 gradient has reduced rapidly, and may become near zero within two decades. In contrast, there was no significant 𝑝CO2 increase on the Chukchi Shelf, where strong and increasing biological uptake has held 𝑝CO2 low, and thus the CO2 sink has increased and may increase further due to the atmospheric CO2 increase. Our findings elucidate the contrasting physical and biological drivers controlling sea surface 𝑝CO2 variations and trends in response to climate change in the Arctic Ocean.
Ouyang Z., Qi, D., Chen, L., Takahashi, T., Zhong, W., DeGrandpre, M.D., Chen, B., Gao, Z., Nishino, S., Murata, A., Sun,H.,. Robbins, L.L, Jin, M., Cai, W. (2020), Sea ice loss amplifies summer-time decadal CO2 increase in the western Arctic Ocean. Nature Climate Change, 10, 678-684. (RGMA)