Ocean Heat Content and Earth Energy Imbalance: new product available

A new product from “altimetry-gravimetry”, developed within the MOHeaCAN project, is now available for download.

It contains monthly time series (between August 2002 and June 2017) of several variables, the main ones being the regional Ocean Heat Content (OHC) (3°x3° spatial resolution grids), the global OHC and the Earth Energy Imbalance (EEI) indicator. Uncertainties are provided for variables at global scale, by propagating errors from sea level measurements (altimetry) and ocean mass content (gravimetry). In order to calculate OHC at regional and global scales, a new estimate of the expansion efficiency of heat at global and regional scales has been performed based on the global ARGO network.

A scientific validation of the MOHeaCAN product has also been carried out performing thorough comparisons against independent estimates based on ARGO data and on the Clouds and the Earth’s Radiant energy System (CERES) measurements at the top of the atmosphere. The mean EEI derived from MOHeaCAN product is 0.84 W.m-2 over the whole period within an uncertainty of ±0.12 W.m-2 (68% confidence level – 0.20 W.m-2 at the 90% CL). This figure is in agreement (within error bars at the 90% CL) with other EEI indicators based on ARGO data (e.g. OHC-OMI from CMEMS) although the best estimate is slightly higher. Differences from annual to inter-annual scales have also been observed with ARGO and CERES data. Investigations have been conducted to improve our understanding of the benefits and limitations of each data set to measure EEI at different time scales.

Product download and documentation is available on the AVISO+ related page.

Users will be mainly interested in ocean heat content time series at regional (grids) and global scales, and Earth energy imbalance time series. Feedback from interested users on this product is welcome.