PUJOL, M.I'., FAUGERE, Y.', PASCUAL, A.?, DIBARBOURE, G.,
MORROW, RR.“ AND SL-TAC TEAM
CLS, France, “IMEDEA, Spain, °CNES, France, *LEGOS, France
1
During the 6 years of Copernicus phase 1, the Sea Level
Thematic Assembly Center (SL-TAC) has been completely
transformed from a demonstration to a fully operational
system. This transformation has been carried out according
three main axes.
First, the consolidation of the production robustness has
been a major priority. Data from four new missions have
been assimilated in 6 years: Jason-3, reference mission for
climate scales (2016), Sentinel-3A (2017) and Sentinel-3B
(since 2019) to complete coverage of mesocales. The
Copernicus constellation is now operational and fully
ingested in the SL-TAC system. To complete this coverage,
the Chinese Collaborative mission HaiYang-2B was
integrated in 2020, still increasing the sampling quality.
From 4 missions in 2015, the near-real time (NRT) system
Is now ingesting operationally 6 missions in 2021, ensuring
the system robustness. The team has been reinforced and
the DUACS software on which the SL-TAC production is
based has been consolidated. Thanks to this efficient
infrastructure, 22 new significant versions, impacting the
product portfolio and content, were implemented.
Then, the SL-TAC team worked on an extension and
improvement of the product portfolio. The gridded products,
highly popular among users, were added to the catalogue
at the beginning of the project (2015), and several regional
products were added after, such as the Europe (2019)
aroduct and Mediterranean & Black Sea Mean Dynamic
Topography (MDT) (2020). A whole set of variables is now
available in products, such as absolute dynamic topography,
geostrophic currents, and all the components needed by
Monitoring Forecasting Centres (MFCs) to adapt the content
of Sealevelto their model. The methodology of development
in interaction with MFCs, initiated in the Tailored Altimeter
Product for Assimilation Systems (TAPAS) group in
MyOcean, has continued during the & years with annual
meetings in order to achieve this evolution. This interaction
detween producers and users was enabled by the
copernicus Marine Service's (CMEMS) unique structure
ncluding observations and models. Two full reprocessing
were also implemented (2018, 2021) leading to major
improvements. The precise multi-missions cross-
calibration provided accurate Ocean Monitoring Indicator
'OMI) such as the Global Mean Sea Level for climate
application. The error budget of products has also been
-efined and promoted through four peer-reviewed
publications (Pujol et al., 2016, Taburet et al 2019, Ballarotta
at al 2019, Sänchez-Romän et al., 2020) and Copernicus
Marine Service Quality Information Documentation (QUID).
Beside evolutions implemented within the Service the SL-
"AC also has been preparing the next generation of
products (with an enhanced special resolution) by
integrating space Agencies (CNES, ESA) R&D. Demonstration
samples, fully exploiting the altimetry content and with
\mproved posting (1 km), have been proposed. Observation
Simulation Experiment (OSE) tests carried out by MFCs
showed a gain up to 10% in the model output assimilating
these data (Benkiran et al., 2017). Similarly, the capacity of
the high-resolution altimetry to improve the sampling of
Sea level through “ice leads” was demonstrated. These
studies allowed us to formulate recommendations to the
Space Agencies concerning evolutions of upstream
products. They also open very exciting prospects for the
next phase of Copernicus Marine Service with new high-
resolution product lines for nadir altimetry and the future
Surface Water Ocean Topographv (SWOT) mission
1. MAIN ACHIEVEMENTS FROM 2015 TO
2021
The SL-TAC has produced multi-mission altimetry Sea Leve
products in NRT and Delayed Time (REP/DT) for MFCs and a
various range of oceanographic applications for externa.
users such as: climate forecastina centers, geophvsical and
