Clément Ubelmann (DATLAS, France); Antoine Delepoulle (CLS, France); Florian Le Guillou (DATLAS, France); Cécile Anadon (CLS, France); Alice Laloue (CLS, France); Sammy Metref (DATLAS, France); Anaelle Treboutte (CLS, France); Marie-Isabelle Pujol (CLS, France); Ronan Fablet (IMT, France); Gérald Dibarboure (CNES, France)

In 2024, a new generation of gridded sea surface height (SSH) products was developed by integrating observations from the current constellation of nadir altimeters and the Surface Water and Ocean Topography (SWOT) mission.

These enhanced Level 4 multi-mission products are freely available via the AVISO+ portal and have recently undergone evaluations aimed at quantifying the added value of SWOT’s KaRIn instrument to the existing altimeter constellation. Notably, incorporating KaRIn data has led to an average reduction of approximately 10% in SSH mapping errors in regions characterized by energetic meso- and submesoscale dynamics. However, certain areas—particularly those affected by intense tropical rainfall, complex tropospheric conditions, storm tracks, or strong internal tide signals—exhibit anomalous responses to KaRIn integration, highlighting the need for improved processing in this complex atmospheric and oceanic variability.

To address these challenges, an experimental update of the multi-mission gridded product has recently been released, featuring enhanced error characterization within the mapping algorithms. Preliminary validation indicates significant improvements. Concurrently, substantial efforts have been made to extend data-driven, dynamic mapping approaches—initially developed for the North Atlantic region—to a global scale. These new methodologies now offer promising perspectives for generating enriched SSH products on a global grid.

This presentation will highlight these validation results and discuss the methodological advancements underpinning these improved gridded products.