DeGrandpre Michael, Evans Wiley, Timmermans Mary-Louise, Krishfield Richard, Williams Bill, Steele Michael
Department of Chemistry and Biochemistry University of Montana Missoula MT USA.
Hakai Institute Heriot Bay British Columbia Canada.
Geophys Res Lett. 2020 Jun 28;47(12):e2020GL088051. doi: 10.1029/2020GL088051. Epub 2020 Jun 13.
Less than three decades ago only a small fraction of the Arctic Ocean (AO) was ice free and then only for short periods. The ice cover kept sea surface CO at levels lower relative to other ocean basins that have been exposed year round to ever increasing atmospheric levels. In this study, we evaluate sea surface CO measurements collected over a 6-year period along a fixed cruise track in the Canada Basin. The measurements show that mean CO levels are significantly higher during low ice years. The CO increase is likely driven by ocean surface heating and uptake of atmospheric CO with large interannual variability in the contributions of these processes. These findings suggest that increased ice-free periods will further increase sea surface CO, reducing the Canada Basin's current role as a net sink of atmospheric CO.
不到三十年以前，北冰洋只有一小部分区域无冰，而且只是短时间无冰。与那些常年暴露于不断增加的大气二氧化碳水平下的其他海洋盆地相比，海冰覆盖使海表二氧化碳水平保持在较低水平。在本研究中，我们评估了沿加拿大海盆一条固定巡航路线在六年期间收集的海表二氧化碳测量数据。测量结果表明，在低冰年份，平均二氧化碳水平显著更高。二氧化碳的增加可能是由海洋表面升温以及大气二氧化碳的吸收所驱动的，这些过程的贡献存在很大的年际变率。这些发现表明，无冰期的增加将进一步提高海表二氧化碳水平，削弱加拿大海盆目前作为大气二氧化碳净汇的作用。
