National Center for Atmospheric Research, Boulder, CO, USA.
Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, USA.
Science. 2021 Dec 3;374(6572):1275-1280. doi: 10.1126/science.abi4355. Epub 2021 Dec 2.
The Southern Ocean plays an important role in determining atmospheric carbon dioxide (CO), yet estimates of air-sea CO flux for the region diverge widely. In this study, we constrained Southern Ocean air-sea CO exchange by relating fluxes to horizontal and vertical CO gradients in atmospheric transport models and applying atmospheric observations of these gradients to estimate fluxes. Aircraft-based measurements of the vertical atmospheric CO gradient provide robust flux constraints. We found an annual mean flux of –0.53 ± 0.23 petagrams of carbon per year (net uptake) south of 45°S during the period 2009–2018. This is consistent with the mean of atmospheric inversion estimates and surface-ocean partial pressure of CO (co)–based products, but our data indicate stronger annual mean uptake than suggested by recent interpretations of profiling float observations.
南大洋在决定大气二氧化碳（CO）方面起着重要作用，但该地区的海气 CO 通量估计值差异很大。在这项研究中，我们通过将通量与大气输送模型中的水平和垂直 CO 梯度相关联，并应用这些梯度的大气观测来估计通量，从而约束了南大洋的海气 CO 交换。基于飞机的垂直大气 CO 梯度测量提供了可靠的通量约束。我们发现，在 2009 年至 2018 年期间，南纬 45°以南的年平均通量为-0.53±0.23 太字节/年（净吸收）。这与大气反演估计和基于表层海洋 CO 分压（co）的产品的平均值一致，但我们的数据表明，年平均吸收量比最近对剖面浮标观测的解释所表明的要强。
