We present a new surface-atmospheric dataset for driving ocean–sea-ice models based on Japanese 55-year atmospheric reanalysis (JRA-55), referred to here as JRA55-do. The JRA55-do dataset aims to replace the CORE interannual forcing version 2 (hereafter called the CORE dataset), which is currently used in the framework of the Coordinated Ocean-ice Reference Experiments (COREs) and the Ocean Model Intercomparison Project (OMIP). A major improvement in JRA55-do is the refined horizontal grid spacing (∼ 55 km) and temporal interval (3 hr). The data production method for JRA55-do essentially follows that of the CORE dataset, whereby the surface fields from an atmospheric reanalysis are adjusted relative to reference datasets. To improve the adjustment method, we use high-quality products derived from satellites and from several other atmospheric reanalysis projects, as well as feedback on the CORE dataset from the ocean modelling community. Notably, the surface air temperature and specific humidity are adjusted using multi-reanalysis ensemble means. In JRA55-do, the downwelling radiative fluxes and precipitation, which are affected by an ambiguous cloud parameterisation employed in the atmospheric model used for the reanalysis, are based on the reanalysis products. This approach represents a notable change from the CORE dataset, which imported independent observational products. Consequently, the JRA55-do dataset is more self-contained than the CORE dataset, and thus can be continually updated in near real-time. The JRA55-do dataset extends from 1958 to the present, with updates expected at least annually. This paper details the adjustments to the original JRA-55 fields, the scientific rationale for these adjustments, and the evaluation of JRA55-do. The adjustments successfully corrected the biases in the original JRA-55 fields. The globally averaged features are similar between the JRA55-do and CORE datasets, implying that JRA55-do can suitably replace the CORE dataset for use in driving global ocean–sea-ice models.

中文翻译：

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基于 JRA-55 的用于驱动海洋的表面数据集 - 海冰模型 (JRA55-do)

我们提出了一个新的地表大气数据集，用于驱动基于日本 55 年大气再分析 (JRA-55) 的海洋-海冰模型，这里称为 JRA55-do。JRA55-do 数据集旨在取代 CORE 年际强迫版本 2（以下称为 CORE 数据集），该数据集目前用于协调海冰参考实验（COREs）和海洋模型比对项目（OMIP）的框架中。JRA55-do 的一个主要改进是改进了水平网格间距（~55 公里）和时间间隔（3 小时）。JRA55-do 的数据生成方法基本上遵循 CORE 数据集的方法，其中大气再分析的表面场相对于参考数据集进行了调整。为了改进调整方法，我们使用源自卫星和其他几个大气再分析项目的高质量产品，以及海洋建模社区对 CORE 数据集的反馈。值得注意的是，地表气温和比湿度是使用多重再分析集合手段来调整的。在 JRA55-do 中，受用于再分析的大气模型中使用的模糊云参数化影响的下流辐射通量和降水基于再分析产品。这种方法代表了 CORE 数据集的显着变化，该数据集导入了独立的观察产品。因此，JRA55-do 数据集比 CORE 数据集更加独立，因此可以近乎实时地持续更新。JRA55-do 数据集从 1958 年到现在，预计至少每年更新一次。本文详细介绍了对原始 JRA-55 字段的调整、这些调整的科学依据以及对 JRA55-do 的评估。这些调整成功地纠正了原始 JRA-55 字段中的偏差。JRA55-do 和 CORE 数据集的全局平均特征相似，这意味着 JRA55-do 可以适当地替换 CORE 数据集，用于驱动全球海洋-海冰模型。