EGU22-7479, updated on 07 Jan 2024
EGU General Assembly 2022
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.

DUACS DT2021: 28 years of reprocessed sea level altimetry products

Yannice Faugère1, Guillaume Taburet1, Maxime Ballarotta1, Isabelle Pujol1, Jean Francois Legeais1, Gwenola Maillard1, Chloe Durand1, Quentin Dagneau1, Marine Lievin1, Antonio Sanchez Roman2, and Gerald Dibarboure3
Yannice Faugère et al.
  • 1CLS, Ramonville, France (
  • 2Imedea, Esporles, Spain
  • 3CNES, Toulouse, France

For more than 23 years, the multisatellite DUACS system has been providing  high quality multi-mission altimetry Sea Level products for oceanographic applications, climate forecasting centers, geophysics and biology communities. They consist in directly usable and easy to manipulate Level 3 (along-track cross-calibrated Sea Level Anomaly SLA) and Level 4 (multiple sensors merged gridded gap-free) products. Global and regional datasets (Arctic Ocean, European Seas ...) are available.

A full reprocessing of these products is carried out almost every 3 years, based on the state-of-the-art Level 2 to Level 4 algorithms. In Decembre 2021, a new version will be available within the Copernicus Marine Environment and Monitoring Service (CMEMS) and the Copernicus Climate Change Service (C3S)  covering 28 years of altimetric data (i.e. almost a century of cumulated data using 24 altimetric missions). This version benefits from major improvements associated with new altimeter and mapping standards.

Here, we report the first results of this DUACS DT2021 multi-mission reprocessing. We first describe the main steps of the altimeter production system. Then, we discuss the characteristics and limits of the different products (C3S, CMEMS) in order to help the ocean and climate communities on their optimal use for validation, assimilation activities and other scientific studies. Several comparisons with independent datasets (along-track, drifters, tide gauges) show that a significant improvement has been achieved at mesoscale with this new version: almost 20% of SLA error reduction at wavelengths [65, 500km] and around 10% of geostrophic currents error reduction compared to the previous version (DT2018). At decadal time scale, the trend of the global mean sea level has been estimated to 3.4 +/- 0.4 mm/yr. (90% Confidence Interval), in line with other estimates and previous reprocessing DUACS-DT2018. New altimeter corrections are also available for the users (internal waves, correction for the Topex-A instrumental drift, flag ice).

How to cite: Faugère, Y., Taburet, G., Ballarotta, M., Pujol, I., Legeais, J. F., Maillard, G., Durand, C., Dagneau, Q., Lievin, M., Sanchez Roman, A., and Dibarboure, G.: DUACS DT2021: 28 years of reprocessed sea level altimetry products, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-7479,, 2022.