SODA Project: SODA3 Ensemble Means and Standard Deviations

The goal of SODA is to reconstruct the historical physical (and eventually biogeochemical) history of the ocean since the beginning of the 20th century. As its name implies, the Simple Ocean Data Assimilation ocean/sea ice reanalysis (SODA) uses a simple architecture based on community standard codes with resolution chosen to match available data and the scales of motion that are resolvable. Agreement with direct measurements (to within observational error estimates) as well as unbiased statistics are expected. While SODA remains a university-based research project, an objective is to support potential users by providing a reliable, well-documented, source of seasonal climate time-scale ocean reanalysis to complement the atmospheric reanalyses available elsewhere (NOAA/EMC, NASA/GMAO, and ECMWF, for example).

SODA3 (SODA Version 3) is the latest release of SODA. The model has been switched to GFDL MOM5/SIS1 with eddy permitting 0.25 degree by 0.25 degree by 50 level resolution (28 kilometers at the Equator down to less than 10 kilometers at polar latitudes), similar to the ocean component of the GFDL CM2.5 coupled climate model, and includes the same SIS1 active sea ice model. A number of improvements have been included in the sequential DA filter, but for many reanalyses SODA3 retains a pre-specified flow-dependent error covariance.

One of the focuses for SODA3 has been to identify, quantify, and limit sources of bias. A major source of bias is in the forward model that predicts the evolution of the flow. A major (but not the only) source of model bias, in turn, is introduced through bias in the meteorological fluxes (heat, freshwater, and momentum). To address this problem SODA3 is an 'ensemble' reanalysis, the spread of whose members provides information about sensitivity to errors in surface forcing. Many of these ensemble members are driven by fluxes that have been bias-corrected.

SODA项目旨在重建自20世纪初期以来海洋的历史物理（以及最终生物地球化学）变迁。正如其名所示，基于社区标准代码的简单海洋数据同化海洋/海冰再分析（SODA）采用了一种简明的架构，其分辨率的选择旨在与可用数据及可解析的运动尺度相匹配。预期与直接测量（在观测误差估计范围内）的一致性以及无偏统计数据的准确性。尽管SODA依然是一个基于大学的科研项目，但其目标之一是通过提供可靠、详尽记录的季节性气候时间尺度的海洋再分析数据源，以补充其他地方可获得的气象再分析数据（例如NOAA/EMC、NASA/GMAO和ECMWF等）。

SODA3（SODA版本3）是SODA的最新发布版本。模型已切换至GFDL MOM5/SIS1，采用允许涡旋的0.25度×0.25度×50层分辨率（赤道处为28公里，极地纬度处小于10公里），与GFDL CM2.5耦合气候模型中的海洋组件相似，并包含相同的SIS1活跃海冰模型。在连续的数据同化滤波器中包含了一些改进，但许多再分析仍保留了预先指定的与流动相关的误差协方差。

SODA3的一个研究重点是识别、量化并限制偏差的来源。偏差的主要来源在于预测流动演化的正向模型。模型偏差的主要（但非唯一）来源是通过气象通量（热量、淡水和动量）的偏差引入。为了解决这一问题，SODA3是一种'集合'再分析，其成员的分布提供了关于对表面强迫误差敏感性的信息。许多这些集合成员是由经过偏差校正的通量驱动的。

搜集汇总

背景与挑战

背景概述

SODA3是一个高分辨率的海洋气候再分析数据集，覆盖1980年至2016年，提供海洋和冰变量的集合平均值和标准偏差，用于研究海洋历史变化及其对气候的影响。