The mean sea surface (MSS) is an important field in physical oceanography, geophysics, and geodesy. In principle, it corresponds to the time-averaged height of the ocean surface. Auxiliary product : mean sea profile above a reference ellipsoid (T/P or WSG84). This surface is available on a regular grid (1/60°x1/60°, 1 minute). The mean sea surface MSS_CNES_CLS2025 (Charayon et al., in prep) has been computed using a 29-year [1993-2021] period of altimetric data. It was built exploring the use of SWOT KaRIn data to propose a new generation MSS able to better represent small wavelengths gapping state-of-the-art nadir-based MSS. Long wavelengths come from a MSS draft chosen to be the Hybrid 23 MSS (https://doi.org/10.24400/527896/a01-2024.002 ) low pass filtered at 20km since this nadir-based MSS model already captured well long wavelengths. The wavelengths shorter than 100km are improved thanks to a SWOT-KaRIn mean profile anomaly to the MSS draft. This mean profile anomaly is built with: - The SWOT-KaRIn science (L3 v3.0 Expert, cycles 1 to 31 included except cycle 17, https://doi.org/10.24400/527896/a01-2023.018) dataset - The experimental multimission gridded L4 sea level heights and velocities with SWOT using MIOST (https://doi.org/10.24400/527896/a01-2025.001 ). - In SWOT diamonds, since KaRIn data are not available, we used another innovation only based on DT2024 1Hz CryoSat2 and AltiKa SSHA data (https://doi.org/10.48670/moi-00146), period from 2010 to 2025, SSHA data relative to MSS Hybrid 23 low pass filtered at 5km. To build this nadir-based innovation, we used the static part of the mapping from MIOST method.

Along-track altimetric GDR (Geophysical Data Record) products , geophysical and environmental corrections to apply. Available missions are: GFO, Topex/Poseidon, Envisat, Cryosat-2, Jason-1, Jason-2, Jason-3, Saral/AltiKa. Missions with several successive orbital types are treated in their entirety. Compared to the original version of the GDR files distributed by the CNES, ESA, NASA and ISRO agencies, the CTOH proposes new corrections and parameters in these files, which are to be applied to the initial altimetry measurement, according to user needs. Children metadata files are available for each mission.

This product integrates sea level observations aggregated and validated from the Regional EuroGOOS consortium (Arctic-ROOS, BOOS, NOOS, IBI-ROOS, MONGOOS) and Black Sea GOOS as well as from the Global telecommunication system (GTS) used by the Met Offices. The latest version of Copernicus delayed-mode Sea level product is also distributed from Copernicus Marine catalogue.

The SIROCCO ocean circulation simulation covers the western Mediterranean Sea ( 33°N - 44.5°N / 1.2°W - 16.3°E ) and the period from 1990 to 2023. It is based on the BlueLion configuration of the Symphonie hydrodynamic model (Marsaleix et al., 2008, 2019). The horizontal resolution of the model bipolar grid (1230 x 1308) varies from 340 m in the northwestern Mediterranean to 4.5 km in the Ionian Sea. The vertical grid has vanishing quasi-sigma 50 levels. This dataset includes daily files of sea surface height, temperature, salinity and current velocities. This simulation was developed in the framework of the PPR RIOMAR. The initial and open boundary conditions, the atmospheric forcing and the rivers discharge (except from the Gulf of Lion) were provided by the CNRM-RCSM6B, regional climate system model (atmosphere, ocean, land surface hydrology) developed at CNRM (Météo-France) over the Mediterranean CORDEX domain (Med-CORDEX). This coupled simulation is based on the NEMO model at 1/12° for the ocean, the Aladin-Climat model at 12 km for the atmosphere and the ISBA-CTRIP land surface hydrology model. The Gulf of Lion rivers were considered using the hydrology database HydroPortail (http ://www.hydro.eaufrance.fr).

Barystatic and manometric sea level changes represent the mass component of sea level changes at global and regional scales, respectively. Barystatic sea level changes are estimated using the sea level budget (SLB) approach combining satellite altimetry with in-situ measurements of the seawater temperature and salinity. This SLB approach is adapted from Barnoud et al., (2023; https://doi.org/10.5194/os-19-321-2023). Manometric sea level variations and their uncertainties are not provided for the SLB approach, due to the high uncertainties associated with the drift of the halosteric component (e.g., Bouih et al., 2025; https://doi.org/10.5194/egusphere-egu24-16813).

The SIROCCO ocean circulation climate simulations cover the western Mediterranean Sea ( 33°N - 44.5°N / 1.2°W - 16.3°E ) and the periods from 2000 to 2020, from 2030 to 2049, and form 2080 to 2099. It is based on the BlueLion configuration of the Symphonie hydrodynamic model (Marsaleix et al., 2008, 2019). The horizontal resolution of the model bipolar grid (1230 x 1308) varies from 340 m in the northwestern Mediterranean to 4.5 km in the Ionian Sea. The vertical grid has vanishing quasi-sigma 50 levels. This dataset includes daily files of sea surface height, temperature, salinity and current velocities. This simulations were developed in the framework of the ANR POPNCO and the PPR RIOMAR. The initial and open boundary conditions, the atmospheric forcing and the rivers discharge were provided by the CNRM-RCSM6B, regional climate system model (atmosphere, ocean, land surface hydrology) developed at CNRM (Météo-France) over the Mediterranean CORDEX domain (Med-CORDEX). This coupled simulation is based on the NEMO model at 1/12° for the ocean, the Aladin-Climat model at 12 km for the atmosphere and the ISBA-CTRIP land surface hydrology model.

Hydrodynamics and sediment dynamics hindcast in the Gironde Estuary (France), produced by coupling the hydrodynamics model MARS3D (with sediment dynamics module MUSTANG) and wave spectral model WAVEWATCH III®.

Times series of water level at four stations of the Gironde Estuary (Pointe de Grave, Le Marquis, Bordeaux and Cadillac) for the the years 1953, 1971, 1982, 1994, 2005 and 2014. The dataset includes all of the time seris used in the publication: To what extent multidecadal changes in morphology and fluvial discharge impact tide in a convergent (turbid) tidal river (2018), Journal of Geophysical Research: Oceans.

The Level-2P (L2P) products are pre-operational homogenized, mono-mission satellite altimetry datasets generated by the DUACS production system. They provide along‑track SLA data together with the full set of standardised geophysical and environmental corrections (e.g., tide‑free sea level, inverse barometer, sea‑state bias, atmospheric corrections). The L2P SLA datasets are the primary input for the higher‑order DUACS processing chain that yields the operational sea‑level (Level-3 and Level-4) products distributed by the Copernicus Marine Service (CMS) and the Copernicus Climate Change Service (C3S). **Processing Timeliness:** - **Near-Real-Time (NRT)**: Rapid delivery windows (under 3h – up to 24h for the newest passes) for operational marine forecasting. - **Short Time Critical (STC)**: Intermediate latency (24h – 3 days) streams optimized for quick-turnaround cal/val and monitoring. - **Non-Time Critical (NTC)**: Science‑quality dataset (30 days – up to 90 days) with the most stable baseline corrections; foundation for long‑term climate analyses. The L2P SLA NRT/STC 20Hz data products version 4.0 (DUACS DT 2024 baseline) are available for the following missions: Jason-3, Sentinel‑6 Michael Freilich (MF) and SWOT. The L2P SLA NTC 1Hz data products version 4.0 (DUACS DT 2024 baseline) are available for the following missions: ERS‑1, TOPEX/Poseidon, ERS‑2, Geosat‑Follow‑On, Jason‑1, Envisat, Jason‑2, CryoSat‑2, Haiyang‑2A, SARAL/AltiKa, Jason‑3, Sentinel‑3A, Sentinel‑3B, Sentinel‑6 Michael Freilich (MF) and SWOT.

Satellite altimeters routinely supply sea surface height (SSH) measurements which are key observations to monitor ocean dynamics. However, below a wavelength of about 70 km, along-track altimeter measurements are often characterized by a dramatic drop in the signal-to-noise ratio, making it very challenging to fully exploit available altimeter observations to precisely analyze small mesoscale variations in SSH. Although various approaches have been proposed and applied to identify and filter noise from measurements, no distinctive methodology emerged to be systematically applied in operational products. To best cope with this unresolved issue, the Copernicus Marine Environment Monitoring Service (CMEMS) actually provides simple band-pass filtered data to mitigate noise contamination in the along-track SSH signals and more innovative and adapted noise filtering methods are thus left to users seeking to unveil small-scale altimeter signals. Here demonstrated, a fully data-driven approach is developed and applied to provide robust estimates of noise-free Sea Level Anomaly (SLA) signals. The method combines Empirical Mode Decomposition (EMD), to help analyze non-stationary and non-linear processes, and an adaptive noise filtering technique inspired by Discrete Wavelet Transform (DWT) decompositions. It is now found to best resolve the distribution of the sea surface height variability in the mesoscale 30-120 km wavelength band. A practical uncertainty variable is attached to the denoised SLA estimates that accounts for errors related to the local signal to noise ratio, but also for uncertainties in the denoising process, which assumes that SLA variability results in part from a stochastic process. Here, measurements from the Jason-3, Sentinel-3 A and SARAL/AltiKa altimeters are processed and analyzed, and their energy spectral and seasonal distributions characterized in the small mesoscale domain. Anticipating data from the upcoming Surface Water and Ocean Topography (SWOT) mission, these denoised SLA measurements for three reference altimeter missions already yield valuable opportunities to assess global small mesoscale kinetic energy distributions. This dataset was developed within the Ocean Surface Topography Science Team (OSTST) activities. A grant was awarded to the SASSA (Satellite Altimeter Short-scale Signals Analysis) project by the TOSCA board in the framework of the CNES/EUMETSAT call CNES-DSP/OT 12-2118. Altimeter data were provided by the Copernicus Marine Environment Monitoring Service (CMEMS) and by the Sea State Climate Change Initiative (CCI) project.