New CNES CLS 2019 Mean Sea Surface: First Validation

Marie-Isabelle Pujol1, Philippe Schaeffer1, Yannice Faugere2, GĂ©rald Dibarboure3 and Nicolas Picot3, (1)Collecte Localisation Satellites, Ramonville Saint-Agne, France, (2)CLS Collecte Localisation Satellites, Ramonville Saint-Agne, France, (3)CNES French National Center for Space Studies, Toulouse, France
The Mean Sea Surface (MSS) model is an essential field for satellite altimeter processing. It is the reference surface that is removed to the SSH altimeter measurement in order to retrieve a sea level anomaly (SLA or SSHA).

Work is ongoing to compute a new CNES_CLS MSS model. It is based on the integration of more than 25 years of altimetric data, using more than 10 altimeters from the historical Topex/Poseidon to the in-flight Sentienl-3A mission. As well as the previous 2015 version this new determination is focused on the fallowing points of improvement which remains a permanent challenge:

  • the correction of ocean variability, especially for wavelengths between 50 and 200 km.
  • the accuracy of altimetric data and therefore of the MSS near the coast, particularly since MSS can serve as a reference for studying the coastal vulnerability.
  • a fine-tuned determination of the Arctic zone, which is a major indicator of climate change.
  • a most accurate mapping of the finest topographic structures for wavelengths less than 30 km, in preparation of a new reference for the upcoming SWOT mission.

We therefore propose a synthesis of analyzes of these different aspects in order to quantify the improvements of this new MSS compared to the other existing models.