Rapid climate warming and sea-ice loss have induced major changes in the sea surface partial pressure of CO₂ (\(p_{{\mathrm {CO}}_2}\)). However, the long-term trends in the western Arctic Ocean are unknown. Here we show that in 1994–2017, summer \(p_{{\mathrm {CO}}_2}\) in the Canada Basin increased at twice the rate of atmospheric increase. Warming and ice loss in the basin have strengthened the \(p_{{\mathrm {CO}}_2}\) 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 \(p_{{\mathrm {CO}}_2}\) increase on the Chukchi Shelf, where strong and increasing biological uptake has held \(p_{{\mathrm {CO}}_2}\) 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 \(p_{{\mathrm {CO}}_2}\) variations and trends in response to climate change in the Arctic Ocean.

快速的气候变暖和海冰的流失已引起了CO ₂的海面分压（\（p _ {{\ mathrm {CO}} _ 2} \））的重大变化。然而，未知北冰洋西部地区的长期趋势。在这里，我们显示在1994–2017年期间，加拿大盆地的夏季\（p _ {{\ mathrm {CO}} _ 2} \）的增长速度是大气增长率的两倍。流域的变暖和冰流失加剧了\（p _ {{\ mathrm {CO}} _ 2} \）季节振幅，导致年代际迅速增加。因此，夏季海气CO ₂梯度迅速减小，并且可能在二十年内接近于零。相反，没有明显的\（p _ {{\ mathrm {CO}} _ 2} \）在楚科奇（Chukchi）架上增加，而生物吸收的增加又使\（p _ {{\ mathrm {CO}} _ 2} \）低，因此，CO ₂汇增加了，并且由于大气中CO _2的增加而可能进一步增加。我们的发现阐明了控制北冰洋\（p _ {{\ mathrm {CO}} _ 2} \）响应于北冰洋气候变化的变化和趋势的物理和生物驱动因素的对比。