The global mean level of the oceans is one of the most important indicators of climate change. It incorporates the reactions from several different components of the climate system. Precise monitoring of changes in the mean level of the oceans, particularly through the use of altimetry satellites, is vitally important, for understanding not just the climate but also the socioeconomic consequences of any rise in sea level.

Multimission altimeter satellite gridded sea surface heights and derived variables computed with respect to a twenty-year mean. Previously distributed by Aviso+, no change in the scientific content. All the missions are homogenized with respect to a reference mission. The acquisition of various altimeter data is a few days at most. The sla is computed with a non-centered computation time window (6 weeks before the date).

Monomission altimeter satellite along-track sea surface heights computed with respect to a twenty-year mean. Previously distributed by Aviso+, no change in the scientific content. All the missions are homogenized with respect to a reference mission which is currently OSTM/Jason-2. The sla is computed with an optimal and centered computation time window (6 weeks before and after the date). Two kinds of datasets are proposed: filtered (nominal dataset) and unfiltered.

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). Another grid provides the estimation of error fields which represent the MSS accuracy estimated through the inverse technique.

The CTOH computes and distributes specific, coastal along-track sea level anomalies (SLA) using its X-TRACK processor over 23 regions, for all precise altimeter missions : Topex/Jason-1/Jason-2/Jason-3 (+Topex Interleaved orbit (TPN)/Jason-1 Interleaved orbit (J1N)), SARAL/AltiKa, Envisat, Geosat Follow On The CTOH computes and distributes specific, coastal along-track sea level anomalies (SLA) using its X-TRACK processor for all precise altimeter missions : Topex/Poseidon (TP), Jason-1 (J1) , Jason-1 interleaved (J1N), Topex/Poseidon interleaved (TPN), Jason-2, Geosat Follow on (GFO) and Envisat. X-TRACK cover today all the coastal oceans, with 23 new regions.

Barystatic and manometric sea level changes represent the mass component of sea level changes at global and regional scales respectively. Barystatic and manometric sea level changes are estimated here using the satellite gravimetry measurements from the GRACE and GRACE-FO missions. Two products are distributed over the April 2002 to August 2022 period: - Barystatic sea level changes from satellite gravimetry with uncertainties at 1-sigma: monthly time series, - Manometric sea level changes from satellite gravimetry with uncertainties at 1-sigma: monthly grids with 1x1 degree.

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.

Barystatic and manometric sea level changes represent the mass component of sea level changes at global and regional scales respectively. Barystatic and manometric sea level changes are estimated here using the sea level budget approach combining satellite altimetry with in situ measurements of the seawater temperature and salinity. This sea level budget approach is adapted from Barnoud et al., (2023). Two products are distributed over the January 1993 to December 2020 period: - Barystatic sea level changes from sea level budget with uncertainties at 1-sigma: monthly time series, - Manometric sea level changes from sea level budget with uncertainties at 1-sigma: monthly grids with 1 degree spacing.

Monomission altimeter product: OSTM/Jason-2. These products were produced by CLS in the framework of the Pistach project, funded by Cnes.