Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germany.
Department of Atmospheric and Oceanic Sciences and Institute of Arctic and Alpine Research, University of Colorado Boulder, Boulder, CO, USA.
Philos Trans A Math Phys Eng Sci. 2023 Jun 26;381(2249):20220063. doi: 10.1098/rsta.2022.0063. Epub 2023 May 8.
Estimates of ocean [Formula: see text] uptake from global ocean biogeochemistry models and [Formula: see text]-based data products differ substantially, especially in high latitudes and in the trend of the [Formula: see text] uptake since 2000. Here, we assess the effect of data sparsity on two [Formula: see text]-based estimates by subsampling output from a global ocean biogeochemistry model. The estimates of the ocean [Formula: see text] uptake are improved from a sampling scheme that mimics present-day sampling to an ideal sampling scheme with 1000 evenly distributed sites. In particular, insufficient sampling has given rise to strong biases in the trend of the ocean carbon sink in the [Formula: see text] products. The overestimation of the [Formula: see text] flux trend by 20-35% globally and 50-130% in the Southern Ocean with the present-day sampling is reduced to less than [Formula: see text] with the ideal sampling scheme. A substantial overestimation of the decadal variability of the Southern Ocean carbon sink occurs in one product and appears related to a skewed data distribution in [Formula: see text] space. With the ideal sampling, the bias in the mean [Formula: see text] flux is reduced from 9-12% to 2-9% globally and from 14-26% to 5-17% in the Southern Ocean. On top of that, discrepancies of about [Formula: see text] (15%) persist due to uncertainties in the gas-exchange calculation. This article is part of a discussion meeting issue 'Heat and carbon uptake in the Southern Ocean: the state of the art and future priorities'.
全球海洋生物地球化学模型和基于观测的[Formula: see text]汇估算与数据产品存在显著差异，尤其是在高纬度地区和 2000 年以来[Formula: see text]汇吸收的趋势方面。在这里，我们通过从全球海洋生物地球化学模型中抽取输出数据来评估数据稀疏对两种基于观测的[Formula: see text]汇估算的影响。从模仿当前采样方案的抽样方案到具有 1000 个均匀分布站点的理想采样方案，海洋[Formula: see text]汇的估算得到了改善。特别是，在当前采样方案中，采样不足导致了[Formula: see text]产品中海洋碳汇趋势的强烈偏差。与当前采样相比，全球[Formula: see text]通量趋势的高估从 20-35%减少到理想采样方案中的不到[Formula: see text]%，南大洋的高估从 50-130%减少到理想采样方案中的不到[Formula: see text]%。在一个产品中，南大洋碳汇的年代际可变性被大大高估，这似乎与[Formula: see text]空间中数据分布的偏斜有关。通过理想采样，全球[Formula: see text]通量均值的偏差从 9-12%减少到 2-9%，南大洋从 14-26%减少到 5-17%。此外，由于气体交换计算的不确定性，仍存在约[Formula: see text]（15%）的差异。本文是“南大洋的热和碳吸收：现状与未来重点”讨论会议的一部分。
