ECCO Ocean Velocity - Daily Mean llc90 Grid (Version 4 Release 4)

This dataset provides daily-averaged ocean velocity on the native Lat-Lon-Cap 90 (LLC90) model grid from the ECCO Version 4 Release 4 (V4r4) ocean and sea-ice state estimate. Estimating the Circulation and Climate of the Ocean (ECCO) ocean and sea-ice state estimates are dynamically and kinematically-consistent reconstructions of the three-dimensional time-evolving ocean, sea-ice, and surface atmospheric states. ECCO V4r4 is a free-running solution of the 1-degree global configuration of the MIT general circulation model (MITgcm) that has been fit to observations in a least-squares sense. Observational data constraints used in V4r4 include sea surface height (SSH) from satellite altimeters [ERS-1/2, TOPEX/Poseidon, GFO, ENVISAT, Jason-1,2,3, CryoSat-2, and SARAL/AltiKa]; sea surface temperature (SST) from satellite radiometers [AVHRR], sea surface salinity (SSS) from the Aquarius satellite radiometer/scatterometer, ocean bottom pressure (OBP) from the GRACE satellite gravimeter; sea ice concentration from satellite radiometers [SSM/I and SSMIS], and in-situ ocean temperature and salinity measured with conductivity-temperature-depth (CTD) sensors and expendable bathythermographs (XBTs) from several programs [e.g., WOCE, GO-SHIP, Argo, and others] and platforms [e.g., research vessels, gliders, moorings, ice-tethered profilers, and instrumented pinnipeds]. V4r4 covers the period 1992-01-01T12:00:00 to 2018-01-01T00:00:00.

本数据集提供了基于原生的经纬度-高程-90（LLC90）网格的每日平均海洋流速，数据来源于ECCO版本4发布4（V4r4）海洋和海冰状态估计。估算海洋环流与气候（ECCO）海洋和海冰状态估计是三维海洋、海冰和表面大气状态随时间演化的动力学与运动学一致重建。ECCO V4r4是MIT通用环流模型（MITgcm）1度全球配置的自由运行解，该解在最小二乘意义上与观测数据相拟合。V4r4所用的观测数据约束包括来自卫星测高仪的海面高度（SSH）[ERS-1/2、TOPEX/Poseidon、GFO、ENVISAT、Jason-1、2、3、CryoSat-2和SARAL/AltiKa]；来自卫星辐射计的海面温度（SST）[AVHRR]、来自Aquarius卫星辐射计/散射计的海面盐度（SSS）、来自GRACE卫星重力仪的海洋底部压力（OBP）；来自卫星辐射计的海冰浓度[SSM/I和SSMIS]，以及通过电导率-温度-深度（CTD）传感器和可抛式深温计（XBTs）从多个项目[例如WOCE、GO-SHIP、Argo等]和平台[例如研究船、水下滑翔机、浮标、冰锚式探测器以及装备了仪器的海豹]测量的现场海洋温度和盐度。V4r4覆盖的时间段为1992年1月1日12:00:00至2018年1月1日00:00:00。