Earth’s energy imbalance (EEI) is a fundamental metric of global Earth system change, quantifying the cumulative impact of natural and anthropogenic radiative forcings and feedback. To date, the most precise measurements of EEI change are obtained through radiometric observations at the top of the atmosphere (TOA), while the quantification of EEI absolute magnitude is facilitated through heat inventory analysis, where ~ 90% of heat uptake manifests as an increase in ocean heat content (OHC). Various international groups provide OHC datasets derived from in situ and satellite observations, as well as from reanalyses ingesting many available observations. The WCRP formed the GEWEX-EEI Assessment Working Group to better understand discrepancies, uncertainties and reconcile current knowledge of EEI magnitude, variability and trends. Here, 21 OHC datasets and ocean heat uptake (OHU) rates are intercompared, providing OHU estimates ranging between 0.40 ± 0.12 and 0.96 ± 0.08 W m⁻² (2005–2019), a spread that is slightly reduced when unequal ocean sampling is accounted for, and that is largely attributable to differing source data, mapping methods and quality control procedures. The rate of increase in OHU varies substantially between − 0.03 ± 0.13 (reanalysis product) and 1.1 ± 0.6 W m⁻² dec⁻¹ (satellite product). Products that either more regularly observe (satellites) or fill in situ data-sparse regions based on additional physical knowledge (some reanalysis and hybrid products) tend to track radiometric EEI variability better than purely in situ-based OHC products. This paper also examines zonal trends in TOA radiative fluxes and the impact of data gaps on trend estimates. The GEWEX-EEI community aims to refine their assessment studies, to forge a path toward best practices, e.g., in uncertainty quantification, and to formulate recommendations for future activities.

地球能量不平衡（EEI）是全球地球系统变化的基本指标，量化自然和人为辐射强迫和反馈的累积影响。迄今为止，EEI 变化最精确的测量是通过大气层顶部 (TOA) 的辐射观测获得的，而 EEI 绝对量级的量化则通过热量库存分析来实现，其中约 90% 的热量吸收表现为增加海洋热含量（OHC）。各个国际组织提供了源自现场观测和卫星观测以及对许多可用观测数据进行重新分析的 OHC 数据集。 WCRP 成立了 GEWEX-EEI 评估工作组，以更好地了解差异、不确定性并协调当前对 EEI 幅度、变异性和趋势的了解。这里，对 21 个 OHC 数据集和海洋吸热 (OHU) 率进行了相互比较，得出 OHU 估计值范围在 0.40 ± 0.12 和 0.96 ± 0.08 W m ⁻² (2005-2019) 之间，当考虑到不平等的海洋采样时，这一差距略有减小这主要归因于不同的源数据、制图方法和质量控制程序。 OHU 的增加率在 − 0.03 ± 0.13（再分析产品）和 1.1 ± 0.6 W m ^-2 dec ^-1 （卫星产品）之间变化很大。更定期地观测（卫星）或基于附加物理知识填充原位数据稀疏区域的产品（一些再分析和混合产品）往往比纯粹基于原位的 OHC 产品更好地跟踪辐射 EEI 变化。本文还研究了 TOA 辐射通量的区域趋势以及数据差距对趋势估计的影响。 GEWEX-EEI 社区旨在完善其评估研究，开辟一条通向最佳实践（例如不确定性量化）的道路，并为未来的活动制定建议。