Global Ocean Heat Content Anomalies based on Argo data

NOTE for users: please use the latest version of the product at https://zenodo.org/doi/10.5281/zenodo.10182972. Ocean Heat Content Anomalies (OHCA) are calculated (during 2005-2022) subtracting the mean over the period 2005-2021 from the monthly time series. Yearly OHCA time series are then calculated. OHC fields are mapped using locally stationary Gaussian processes with data-driven decorrelation scales (Kuusela and Stein, 2018). A linear time trend was included in the estimate of the mean field (along with spatial terms and harmonics for the annual cycle). In the present version, mapping is done in latitude and longitude with monthly subsets of data (a future version will add time to the mapping). Mapping is done separately for different vertical sections. Different vertical sections are combined to estimate: 1. Global OHC timeseries (e.g., for level 0-2000m: GCOS_0000_2000_OHCA_J_m2_oc, for OHC in J/m2; GCOS_0000_2000_OHCA_ZJ, for OHC in ZJ; the attribute “GCOS_area” is included for both variable types in the netcdf file and it tells the corresponding surface area); 2. Volume averaged temperature anomaly (global) timeseries (e.g., for level 0-2000m: GCOS_0000_2000_vol_ave_temp_anom, in degC; the attribute “GCOS_volume'' is included for this variable type in the netcdf file and it tells the corresponding volume). Regions of the ocean that are shallower than 300 m or are not sufficiently well sampled by the Argo array are not included.用户须知：请使用 https://zenodo.org/doi/10.5281/zenodo.10182972 提供的最新版本产品。海洋热含量距平（Ocean Heat Content Anomalies, OHCA）的计算方式为：在2005-2022年时段内，将月度时间序列减去2005-2021年的平均值，随后据此生成年度海洋热含量距平时间序列。海洋热含量场（OHC fields）采用局地平稳高斯过程结合数据驱动的去相关尺度进行映射（参考Kuusela与Stein, 2018）。在平均场的估算模型中，纳入了线性时间趋势项，同时包含空间项与年循环的谐波项。当前版本的映射基于纬度与经度维度，采用月度数据子集开展（未来版本将在映射流程中加入时间维度）。映射针对不同垂直剖面分别进行，随后整合各垂直剖面的结果以估算两类指标：1. 全球海洋热含量时间序列（例如，0-2000米深度层的相关变量：以焦耳每平方米为单位的GCOS_0000_2000_OHCA_J_m2_oc、以泽焦耳为单位的GCOS_0000_2000_OHCA_ZJ；netcdf文件中两类变量均附带属性GCOS_area，用于指示对应的海洋表面积）；2. 全球体积平均温度距平时间序列（例如，0-2000米深度层的GCOS_0000_2000_vol_ave_temp_anom，单位为摄氏度；该变量类型附带属性GCOS_volume，用于指示对应的海洋体积）。水深不足300米或阿尔戈（Argo）阵列采样不足的海洋区域未被纳入本数据集。