Many studies involving surface radiative fluxes rely on surface fluxes retrieved by the Clouds and the Earth's Radiant Energy System (CERES) project or derived from spaceborne cloud radar and lidar observations (CloudSat‐CALIPSO). In particular, most climate models that participated in the Coupled Model Intercomparison Project Phase 5 (CMIP5) were found to have too little shortwave (SW) radiation being reflected back to space and excessive SW radiation reaching the surface over the Southern Ocean—an error with significant consequences for predicting both regional and global climate. There have been few evaluations of CERES or CloudSat retrievals over the Southern Ocean. In this article, CERES and CloudSat retrieved surface SW and longwave (LW) downwelling fluxes are evaluated using surface observations collected over the Southern Ocean during the Macquarie Island Cloud and Radiation Experiment (MICRE). Overall, biases (CERES—surface observations) in the CERES‐surface fluxes are found to be slightly larger over Macquarie Island than most other regions, approximately +10 W m⁻² for the SW and −10 W m⁻² for the LW in the annual mean, but with significant seasonal and diurnal variations. If the Macquarie observations are representative of the larger SO, these results imply that CMIP5 model errors in SW surface fluxes are (if anything) somewhat larger than previous evaluation studies suggest. The bias in LW surface flux shows a marked increase at night, which explains most of the total LW bias. The nighttime bias is due to poor representation of cloud base associated with low clouds.

中文翻译：

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对南洋麦格理岛上CERES和CloudSat表面辐射通量的评估

许多涉及表面辐射通量的研究都依赖于由云和地球辐射能系统（CERES）项目获得的表面通量，或者源自星云雷达和激光雷达观测（CloudSat-CALIPSO）得出的表面通量。特别是，发现大多数参与“互模模型比较项目”第5阶段（CMIP5）的气候模型都无法将短波（SW）辐射反射回太空，并且过多的SW辐射到达南大洋地表—这是一个误差。对预测区域和全球气候都将产生重大影响。对南大洋上的CERES或CloudSat检索几乎没有评估。在这篇文章中，使用麦格理岛云与辐射实验（MICRE）期间在南大洋上收集到的地面观测资料，评估了CERES和CloudSat取回的地面软件和长波（LW）下行流通量。总体而言，发现麦格理岛上CERES地表通量的偏差（CERES-地表观测值）比大多数其他地区略大，大约+10 W m^-2为SW和-10脉冲W M ^-2为在年度平均值的LW，但与显著季节和昼夜变化。如果Macquarie观测值代表较大的SO，则这些结果表明SW表面通量中的CMIP5模型误差（如果有的话）比以前的评估研究建议的要大一些。LW表面通量的偏差在夜间显示出明显的增加，这解释了大部分LW偏差。夜间偏差是由于与低云有关的云层表示不佳。