ECCO Ocean Mixed Layer Depth - Monthly Mean llc90 Grid (Version 4 Release 4)

This dataset provides monthly-averaged ocean mixed layer depth 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.

本数据集提供了来自海洋环流与气候估算（Estimating the Circulation and Climate of the Ocean, ECCO）第4版本第4次发布（V4r4）的海洋与海冰状态估计产品中，原生经纬向封顶90度（Lat-Lon-Cap 90, LLC90）模型网格上的月平均海洋混合层深度。海洋环流与气候估算（ECCO）项目的海洋与海冰状态估计产品，是对三维时变海洋、海冰及地表大气状态的动力与运动学一致重构结果。ECCO V4r4是基于麻省理工学院通用环流模型（MIT general circulation model, MITgcm）1°全球配置版本的自由运行解，并以最小二乘拟合方式匹配观测数据。V4r4所采用的观测数据约束包括：卫星高度计获取的海表高度（sea surface height, SSH）[ERS-1/2、TOPEX/Poseidon、GFO、ENVISAT、Jason-1/2/3、CryoSat-2及SARAL/AltiKa]；卫星辐射计获取的海表温度（sea surface temperature, SST）[AVHRR]；Aquarius卫星辐射散射计获取的海表盐度（sea surface salinity, SSS）；GRACE卫星重力计获取的海底压力（ocean bottom pressure, OBP）；卫星辐射计获取的海冰浓度[SSM/I与SSMIS]；以及多个项目[例如WOCE、GO-SHIP、Argo等]和平台[例如科研船舶、滑翔机、锚系浮标、冰系剖面仪及标记鳍足类动物]通过导温盐（conductivity-temperature-depth, CTD）传感器与抛弃式温深计（expendable bathythermographs, XBT）测得的原位海洋温盐数据。V4r4的时间覆盖范围为1992年1月1日12:00:00至2018年1月1日00:00:00。