4DAtlantic-OHC project is funded by the European Space Agency (ESA).

At global scale the OHC estimation is a very good proxy to monitor the EEI. The ESA MOHeaCAN project has successfully explored the feasibility to monitore the Global Ocean Heat Content from an Earth Observations (EO) based (altimetry – gravimetry) product. It was the first time that a global estimate of the OHC changes and the related changes in EEI from Spatial Observations has been made.

The objective of the 4DAtlantic-OHC project is focused on the Atlantic ocean and provides the opportunity to extend the MOHeaCAN’s work at regional scale where new challenges need to be taken up. Indeed, a series of processes and parameters (coastal area, mixed layer variability,...) that could be neglected at global scale cannot be neglected at regional scale anymore. Thus we need to explore the capability of EO missions and EO-based products in terms of space and time resolution to monitor the regional OHC in the Atlantic ocean. In addition, we need to develop a proper scheme to characterise and then propagate the uncertainty of the input measurements to derive reliable uncertainties of the final estimate of the regional OHC.

The 4DAtlantic-OHC objectives are:

• to refine the global algorithm to develop, test and validate a regional EO-based Atlantic OHC product to enable a realistic monitoring of the Atlantic ocean heat uptake and to understand the role played by the Atlantic Ocean in the climate system.

• to use and analyse the products to better understand the complexity of the Earth and climate system. The investigation will be focused on the Meridional Heat Transport (MHT) in the North Atlantic with a regional heat budget.

• to promote and use the product to assess its strengths and limitations for the implementation of new solutions for society through 3 use cases performed by our early adopters.