Air–sea flux of carbon dioxide (CO₂) is a critical component of the global carbon cycle and the climate system with the ocean removing about a quarter of the CO₂ emitted into the atmosphere by human activities over the last decade. A common approach to estimate this net flux of CO₂ across the air–sea interface is the use of surface ocean CO₂ observations and the computation of the flux through a bulk parameterization approach. Yet, the details for how this is done in order to arrive at a global ocean CO₂ uptake estimate vary greatly, enhancing the spread of estimates. Here we introduce the ensemble data product, SeaFlux (Gregor and Fay, 2021, https://doi.org/10.5281/zenodo.5482547​​​​​​​, https://github.com/luke-gregor/pySeaFlux, last access: 9 September 2021​​​​​​​); this resource enables users to harmonize an ensemble of products that interpolate surface ocean CO₂ observations to near-global coverage with a common methodology to fill in missing areas in the products. Further, the dataset provides the inputs to calculate fluxes in a consistent manner. Utilizing six global observation-based mapping products (CMEMS-FFNN, CSIR-ML6, JENA-MLS, JMA-MLR, MPI-SOMFFN, NIES-FNN), the SeaFlux ensemble approach adjusts for methodological inconsistencies in flux calculations. We address differences in spatial coverage of the surface ocean CO₂ between the mapping products, which ultimately yields an increase in CO₂ uptake of up to 17 % for some products. Fluxes are calculated using three wind products (CCMPv2, ERA5, and JRA55). Application of a scaled gas exchange coefficient has a greater impact on the resulting flux than solely the choice of wind product. With these adjustments, we present an ensemble of global surface ocean pCO₂ and air–sea carbon flux estimates. This work aims to support the community effort to perform model–data intercomparisons which will help to identify missing fluxes as we strive to close the global carbon budget.

中文翻译：

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SeaFlux：使用标准化方法协调来自地表 pCO2 数据产品的海气 CO2 通量

二氧化碳 (CO ₂ )的海气通量是全球碳循环和气候系统的重要组成部分，在过去十年中，海洋清除了人类活动排放到大气中的约四分之一的 CO ₂。估算穿过海气界面的这种 CO ₂净通量的一种常用方法是使用表面海洋 CO ₂观测并通过整体参数化方法计算通量。然而，为了得出全球海洋 CO ₂吸收估计值而进行的操作的细节差异很大，这增加了估计值的传播范围。这里我们介绍集成数据产品 SeaFlux (Gregor and Fay, 2021, https://doi.org/10.5281/zenodo.5482547 ， https://github.com/luke-gregor/pySeaFlux，最后访问时间：2021 年 9 月 9 日 )；该资源使用户能够协调一系列产品，这些产品将表层海洋 CO ₂ 观测值内插到近全球覆盖范围，并使用通用方法来填补产品中的缺失区域。此外，数据集提供了以一致方式计算通量的输入。利用六种基于全球观测的测绘产品（CMEMS-FFNN、CSIR-ML6、JENA-MLS、JMA-MLR、MPI-SOMFFN、NIES-FNN），SeaFlux 集合方法可针对通量计算中的方法论不一致进行调整。我们解决了制图产品之间海洋表面 CO ₂空间覆盖的差异，这最终会导致 CO ₂增加某些产品的吸收率高达 17%。使用三种风产品（CCMPv2、ERA5 和 JRA55）计算通量。与仅选择风产品相比，按比例换气系数的应用对产生的通量具有更大的影响。通过这些调整，我们提出了全球表层海洋p CO ₂和海气碳通量估计的集合。这项工作旨在支持社区进行模型数据比对的努力，这将有助于在我们努力关闭全球碳预算时确定缺失的通量。