Sea Surface Salinity (SSS) is an Essential Climate Variable (ECV) that plays a fundamental role in the density-driven global ocean circulation, the water cycle and climate.

The satellite SSS observation from the Soil Moisture and Ocean Salinity (SMOS), Aquarius, and Soil Moisture Active Passive (SMAP) missions have provided an unprecedented opportunity to map SSS over the global ocean since 2010 at 40-150km scale with a revisit every 2 to 3 days. This observation capability has no historic precedent and has brought new findings concerning the monitoring of SSS variations related with climate variability such as El NiƱo-Southern Oscillation, Indian Ocean Dipole, and Madden-Julian Oscillation, and the linkages of the ocean with different elements of the water cycle such as evaporation and precipitation and continental runoff. It has enhanced the understanding of various ocean processes such as tropical instability waves, Rossby waves, mesoscale eddies and related salt transport, salinity fronts, hurricane haline wake, river plume variability, cross-shelf exchanges. There is also an emerging use of satellite SSS to study ocean biogeochemistry, e.g. linked to air-sea CO2 fluxes.

Following the success of the initial oceanographic studies implementing this new variable, the European Space Agency (ESA) funded a new Climate Change Initiative (CCI) Sea Surface Salinity (SSS) project (2018-2020). The CCI+SSS project (2018-2020) aims to generate improved calibrated global SSS fields over a 10 year period (2010-2019) from all available satellite L-band radiometer measurements, extended at regional scale to 2002-2019 from C-band radiometer measurements. It will fully exploit the ESA/Earth explorer SMOS mission complemented with SMAP and AQUARIUS satellite missions. The project gathers teams involved in earth observation remote sensing, in the validation of satellite data and in climate variability study.

CCI SSS will provide data products that are specifically adapted to climate applications (i.e. include information on accuracy and uncertainty within the data). Furthermore, this project will explore the need to improve the performance of current SSS algorithm retrievals and directly contribute to climate science studies submitted to the next International Panel on Climate Change (IPCC) Annual Review for climate change in 2020.

Frequently Asked Questions

What is SSS?

SSS stands for Sea Surface Salinity. For more information please refer to the Useful Links section above.

Where can I find SSS data?

Links to data provided by this project can be found in the Data section above. Alternative data sources can be found in the Related Links section.

What is CCI?

CCI stands for the Climate Change Initiative. The CCI is a programme initiated by ESA. For more information please refer to the CCI homepage

What is ECV?

ECV stands for Essential Climate Variable. For more information please refer to the ECV Inventory page.

What is ESA?

ESA stands for the European Space Agency. For more information please visit the ESA website.

What is EO?

EO stands for Earth Observation