Ocean-surface optical parameters: reflectances

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.

Gridded multi-mission merged satellite significant wave height in Near-Real-Time. It merges along-track SWH data from the following missions: Jason-3, Sentinel-3A, Sentinel-3B, SARAL/AltiKa, Cryosat-2 and CFOSAT.

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.

Biological parameters: Chlorophyll (several algorithms), Particulate Organic/Inorganic Carbon, Fluorescence…

The Ocean Heat Content ("OHC") is estimated from the measurement of the thermal expansion of the ocean based on differences between the total sea-level content derived from altimetry measurements and the mass content derived from gravimetry data, noted “altimetry-gravimetry”. The Earth Energy Imbalance ("EEI") indicator is derived from the temporal variations of the ocean heat content, i.e. by calculating its derivative (called the ocean heat uptake). The product is delivered in two distinct files. The main one contains the essential variables like Global Ocean Heat Content, Earth Energy Imbalance time series and their relative variance-covariance matrices. The second file contains more variables than the first product like time series of Ocean Mass, Sea Level et Steric Sea Level change grids. It also includes additional variables that were not used for the Global ocean heat content calculation, such as the Global mean of ocean mass, Global mean sea level and Global mean steric sea level time series, but which may nevertheless be of interest to users. Users will therefore be able to find, among other things : - the regional map of the Ocean Heat Content trends (see image associated with this metadata sheet), - global ocean heat content change time series (representative of the globe within the extent of data availability), - earth energy imbalance time series (from global OHC filtered-out from signals lower than 3 years), - the uncertainties associated with these two datasets.

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.

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.

Eddies detected in Delayed-Time (DT) for the entire period [1993 - present]. Variables provided include day-by-day, and for one rotation type (Cyclonic/Anticyclonic) : - Center position (Longitude and latitude of the center of the best fit circle with the contour of maximum circum-average geostrophic speed); - Amplitude (|SSH(local_extremum) – SSH(outermost_contour)|); - Speed radius (Radius of the best fit circle with the contour of maximum circum-average geostrophic speed); - Speed average (Average geostrophic speed of the contour defining the speed radius); - Speed profile (Profile speed average values from effective contour inwards to smallest inner contour); - Effective contour (Largest contour of the detected eddy); - Speed contour (Contour of maximum circum-average geostrophic speed for the detected eddy).