Synthetic along-track altimetry data over 1993-2018 from a NEMO-based simulation of the IMHOTEP project

"Synthetic observations" of along-track SSH have been extracted online during the production of the global, NEMO-based experiment ** IMHOTEP-GAIc**, at every single time and locations where a true SLA observation exists in the AVISO database for the along-track altimetry from the TOPEX, Jason-1, Jason-2 and Jason-3 satellite continuous series over the period 1993-2018. This global ocean/sea-ice/iceberg simulation uses the NEMO model, and has a horizontal resolution of 1/4°. The atmospheric forcing applied at the surface is based on the JRA reanalysis (Kobayashi et al., 2015) and varies over the full range of time-scales from 6 hours to multi-decadal. The freshwater runoff forcing applied to the experiment is fully-variable (monthly to multi-decadal) based on the ISBA hydrographic reanalysis for rivers (Decharme et al., 2019) and from altimeter data and regional GCM simulations for the liquid and solid discharges from the Greenland ice-sheet (Mouginot et al 2019). These runoffs are only climatological around Antarctica.<br> The synthetic along-track SSH dataset from the model is available over the altimetry period (1993-2018) on Zenodo. It is provided there along with a time-mean model SSH (gridded model field) over the same period that can be used as a proxy for mean dynamic topography ("MDT"). See the README file for more information.沿轨海平面高度（along-track SSH）的合成观测已在基于NEMO模式开发的全球试验**IMHOTEP-GAIc**的制作流程中在线提取，提取的时空点位完全匹配1993-2018年间TOPEX、Jason-1、Jason-2及Jason-3卫星连续沿轨测高任务在AVISO数据库中收录的所有真实海平面高度异常（Sea Level Anomaly, SLA）观测的时间与位置。该全球海洋-海冰-冰山模拟采用NEMO模式，水平分辨率为1/4°。试验采用的地表大气强迫场基于JRA再分析资料（Kobayashi等，2015），其时间尺度覆盖6小时至多年代际全范围。本试验的淡水径流强迫场具备全时变特性（时间尺度覆盖月际至多年代际）：河流径流部分基于ISBA水文再分析资料（Decharme等，2019），格陵兰冰盖液态与固态径流部分则源自测高数据及区域全球气候模式（General Circulation Model, GCM）模拟结果（Mouginot等，2019）。仅在南极周边区域，上述径流采用气候态数据。 该模式生成的沿轨海平面高度合成数据集已在Zenodo平台发布，覆盖测高任务时段（1993-2018年）。同步提供的还包含同期的模式时间平均海平面高度场（网格化模式场），可作为平均动态地形（Mean Dynamic Topography, MDT）的替代数据。更多详情请参阅自述文件（README）。