GODAS全球海洋再分析资料(1980-2020)

全球海洋资料同化系统（Global Ocean Data Assimilation System，GODAS）由美国环境预报中心（NCEP）发展，为全球预测系统（global Climate Forecast System, CFS）提供海洋初始场。GODAS数据集即为GODAS同化系统产生的实时的再分析全球海洋资料。GODAS基于GFDL MOM.v3（Geophysical Fluid Dynamics Laboratory’s Ocean Model version 3）准全球海洋模式，该模式覆盖了74°S－65°N的海洋，GODAS的强迫场为动量通量、热通量和淡水通量（NCEP 2大气再分析资料），模式顶层温度为逐周海温分析资料，海表盐度为逐年盐度平均。GODAS不但同化了温度剖面，还同化了合成盐度廓线（通过温－盐关系计算得到），在2007年3月之后，海平面高度计资料也参加了同化。本同化系统采用三维变分，其中参加同化的海温资料包括XBTs、TAO、TRITON和PIRATA系泊和Argo剖面探测浮标。GODAS数据集的缺点在于严重低估了盐度的变率，其速度场也存在很大误差。

The Global Ocean Data Assimilation System (GODAS) was developed by the U.S. National Centers for Environmental Prediction (NCEP) to provide ocean initial conditions for the Climate Forecast System (CFS). The GODAS dataset refers to real-time reanalyzed global ocean data generated by the GODAS assimilation system. GODAS is based on the GFDL MOM.v3 (Geophysical Fluid Dynamics Laboratory’s Ocean Model version 3) quasi-global ocean model, which covers ocean areas between 74°S and 65°N. The forcing fields of GODAS include momentum fluxes, heat fluxes and freshwater fluxes derived from NCEP 2 atmospheric reanalysis data. The model's top-layer temperature is constrained by weekly sea surface temperature analysis data, while sea surface salinity is set as the annual average salinity. GODAS assimilates not only temperature profiles but also synthetic salinity profiles calculated via the temperature-salinity relationship. Since March 2007, sea level altimeter data have also been incorporated into the assimilation process. This assimilation system adopts the 3-dimensional variational (3D-Var) method. The sea temperature observations involved in the assimilation include XBTs, TAO, TRITON, PIRATA moored buoys and Argo profiling floats. The main limitations of the GODAS dataset are its severe underestimation of salinity variability and considerable errors in its velocity field.

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GODAS全球海洋再分析资料（1980-2020）是由美国环境预报中心开发的全球海洋数据集，用于为气候预测系统提供海洋初始场，基于GFDL MOM.v3模式并同化了多种观测资料（如温度剖面和盐度廓线）。该数据集覆盖全球海洋（74°S-65°N），具有月和候时间分辨率以及1/3°×1°的空间分辨率，但存在低估盐度变率和速度场误差较大的局限性，仅限非盈利研究使用。