Pan-Arctic monthly maps of sea surface height anomaly and geostrophic velocity from the satellite altimetry Cryosat-2 mission, 2011-2020@en

This data set was created with the aim of supporting observational studies of the sea level and surface ocean circulation variability in the Arctic Ocean. The data set was created in the frame of the Regional Atlantic Circulation and global changE (RACE) project. It consists of monthly maps of the Arctic sea surface height anomaly and absolute geostrophic velocity generated from sea surface height observations taken by the European Space Agency's satellite mission Cryosat-2. The dataset spans the period 2011-2020 and was generated by interpolation of satellite altimetry along-track observations onto a regular latitude-longitude grid of resolution 0.25°X0.75°. The sea surface height anomaly observations along the Cryosat-2 satellite tracks used in this work are, for the ice-covered ocean, data from the Alfred Wegner Institute (AWI version 2.4, ftp://ftp.awi.de/sea_ice/projects/cryoawi_ssh), and for the open ocean, data from the Radar Altimetry Database System (RADS, http://rads.tudelft.nl/rads/rads.shtml). The merged AWI+RADS along track data, processed as described in Doglioni et al., 2022 and used to generate the monthly maps, are included in the present file. The along track observations are interpolated on the output grid using the Data-Interpolating Variational Analysis tool (Troupin et al., 2012) with a decorrelation length of 50 km. Detailed methodology for the derivation and assessment of the dataset can be found in Doglioni et al., 2022 (under review). As auxiliary variables, the bin-average of along track sea surface height anomaly, the bin-standard deviation and the number of observations per bin are included.本数据集旨在支撑北冰洋海平面与海洋表层环流变异的观测研究。数据集依托区域大西洋环流与全球变化（Regional Atlantic Circulation and global changE, RACE）项目框架构建。数据集包含由欧洲空间局（European Space Agency）Cryosat-2卫星任务获取的海平面高度观测数据反演得到的北极海平面高度异常与绝对地转流速月均格点场。数据集时间跨度为2011-2020年，通过将卫星测高沿轨观测数据插值至分辨率为0.25°×0.75°的规则经纬网格生成。本研究使用的Cryosat-2卫星沿轨海平面高度异常观测数据分为两类：冰覆盖海域数据来自阿尔弗雷德·魏格纳研究所（Alfred Wegner Institute, AWI 版本2.4，数据源地址：ftp://ftp.awi.de/sea_ice/projects/cryoawi_ssh）；开阔海域数据则来自雷达测高数据库系统（Radar Altimetry Database System, RADS，数据源地址：http://rads.tudelft.nl/rads/rads.shtml）。本文件同时包含经合并的AWI+RADS沿轨数据集，该数据集按照Doglioni等人2022年的研究方法处理后，用于生成本次的月均格点场。沿轨观测数据通过数据插值变分分析工具（Data-Interpolating Variational Analysis, DIVA，Troupin et al., 2012）进行网格插值，插值时设置的去相关长度为50 km。该数据集的推导与评估详细方法可参见Doglioni等人2022年的待刊研究成果。作为辅助变量，本数据集同步包含沿轨海平面高度异常的分箱平均值、分箱标准差以及每个分箱内的观测样本数。