NAPv1.0: A seasonal hydrographic gridded data set for the Northern Antarctic Peninsula, Southern Ocean

The Northern Antarctic Peninsula (NAP) climatology version 1 (NAPv1.0) was built by optimally interpolate hydrographic data sets from the CTD, MEOP and Argo floats profiles sampled in the NAP and adjacent regions during the period of 1990-2019. The database consists of data from the World Ocean Database, Pangaea, Hutchinson et al. (2020), Brazilian High Latitude Oceanography Group (GOAL; http://goal.furg.br/), Marine Mammals Exploring the Oceans Pole to Pole consortium (MEOP), and Argo floats. The climatology has outputs for summer (Jan-Mar), autumn (Apr-Jun), winter (Jul-Sep) and spring (Oct-Dec). The profiles were first linearly interpolated onto 90 depth levels, and then optimally interpolated in space using a grid of ~10 km resolution. The grid spacing is 0.09˚ along latitudes and 0.2˚ along longitudes (i.e., 0.09˚ latitude x 0.09˚/cos(63˚S) longitude, where 63˚S is the mean latitude of our domain). A series of tests were made to find the appropriate smoothing lengthscale and the a priori relative error in order to find a balance between smoothness and feature representativeness. The final smoothing lengthscale (i.e. the radius of influence of the interpolation) chosen was 1˚ in latitude and longitude, and the a priori relative error allowed was set to 0.2 for the objective interpolation algorithm. The same constants were set for all depth levels and all variables. The regions where the mapping relative error was higher than 0.5 were excluded. The NAPv1.0 climatology can be used for several applications, including input data for ocean and climate models initialization/assessment and ocean reanalysis evaluation, as well as to produce and reconstruct biogeochemical properties. The NAPv1.0 climatology represents the ocean mean-state for the NAP for the end of the 20th and early 21st-century. <strong>Reference: </strong><br> Dotto, T. S., Mata, M. M., Kerr, R., and Garcia, C. A. E.: A novel hydrographic gridded data set for the northern Antarctic Peninsula, Earth Syst. Sci. Data, 13, 671–696, https://doi.org/10.5194/essd-13-671-2021, 2021.南极半岛北部（Northern Antarctic Peninsula, NAP）气候学数据集版本1（NAPv1.0）由1990-2019年间于NAP及其邻近海域采集的温盐深剖面仪（Conductivity-Temperature-Depth, CTD）、跨极海洋探索海洋哺乳动物联盟（Marine Mammals Exploring the Oceans Pole to Pole, MEOP）与Argo浮标剖面的水文数据集经最优插值构建而成。该数据集的数据源包括世界海洋数据库（World Ocean Database）、潘盖亚数据库（Pangaea）、Hutchinson等人（2020）的研究数据、巴西高纬度海洋学小组（Brazilian High Latitude Oceanography Group, GOAL; http://goal.furg.br/）、跨极海洋探索海洋哺乳动物联盟（MEOP）以及Argo浮标数据。该气候学数据集提供四季输出结果，其中夏季为1-3月、秋季为4-6月、冬季为7-9月、春季为10-12月。所有剖面首先被线性插值至90个深度层，随后以约10公里分辨率的网格为基础开展空间最优插值。该网格的纬向间距为0.09°，经向间距为0.2°（即纬向0.09° × 经向0.09°/cos(63°S)，其中63°S为研究区域的平均纬度）。为在平滑性与特征代表性之间取得最优平衡，研究团队开展了一系列测试，以确定合适的平滑长度尺度与先验相对误差。最终选定的平滑长度尺度（即插值的影响半径）为经纬度方向均1°，目标插值算法允许的先验相对误差设为0.2。所有深度层与各变量均采用相同的上述常数设置。制图相对误差大于0.5的区域被排除在数据集之外。NAPv1.0气候学数据集可应用于多个科研场景，包括作为海洋与气候模式初始化/评估的输入数据、海洋再分析结果的验证，以及生成与重建生物地球化学参数。NAPv1.0气候学数据集表征了20世纪末至21世纪初NAP海域的海洋平均状态。<strong>参考文献：</strong><br> Dotto, T. S., Mata, M. M., Kerr, R. 与 Garcia, C. A. E.：《南极半岛北部新型网格化水文数据集》，《地球系统科学数据》（Earth Syst. Sci. Data），13卷，671–696页，https://doi.org/10.5194/essd-13-671-2021，2021年。