Project Overview

Southern Ocean Freshwater (SO Fresh) is a recent ESA funded project (2021-2023) included in the Polar Cluster Initiative. Polar Cluster aims at establishing collaboration with the existing projects in polar areas to put into value of unique, added-value capabilities from ESA missions and remote sensing missions in general. SO FRESH goals are to improve our understanding of the different processes governed or affected by freshwater fluxes taking place at the Southern Ocean.

SO Fresh scientific objectives are based in four specific case studies aiming at:

  1. to improve our understanding on the changes in Sea Ice;
  2. to characterize the drivers of the formation of the Weddell Polynya in 2016-2017;
  3. to assess the impact on Sea Ice melting due to changes in coastal processes;
  4. to analyse the formation of deep water via remote sensing variables.

Sea Surface Salinity (SSS) is a key ocean variable for the four case studies. SO Fresh will explore the potential of using SSS in combination with other ocean variables (i.e. Sea Surface Temperature, Sea Surface Height Anomalies) to enhance the state of the art of SO freshwater fluxes, Sea Surface Density variability and Water Mass Transformation Rates.

With lessons learned in most recent advancements in SSS processing in the context of ESA SMOS Mission, SO Fresh will produce a dedicated SSS product Southern Ocean. Some of the methodologies to improve SSS data around the Antarctic peninsula may include nodal sampling, Brightness temperature fusion and enhanced debiased non-Bayesian retrievals.

SO Fresh started in May 2021, and the first set of data is expected to be available for distribution by the beginning of 2022. To keep in touch with SO Fresh Team, follow the link or send email to

SO Fresh


  • Establish connections with on-going projects in the Southern Ocean and survey their user requirements to use EO-based SSS products.

  • Generate a long-term (from 2011 up to present) open-access salinity dataset to be publicly providedto the scientific community.

  • Assess causes and consequences of recent sea ice changes.

  • Build a science network community between ESA and EU Polar science communities. This project will create an appropriate space to boost critical discussion within the Antarctic science community at a broad scale.

  • Develop a new algorithm and implement novel approaches to produce a high-quality SSS product that responds to the User Requirements in the Southern Ocean

  • Generate a Roadmap describing future work to better characterize and understand the freshwater cycle of the Southern Ocean and how it will change in the future.This will set the path to enable the communication of new findings into actionable solutions for society.

  • Determine changes in coastal processes and their impact on ice sheet melting and abyssal water formation.

  • Assess causes and consequences of the appearance of the Weddell Polynya.

Data Access

SO Fresh aims to achieve a community study of the impact of the new satellite retrieved Sea Surface Salinity (SSS) and other EO products (SST, SSD and SSC). Any feedback about the quality and usability of this new dataset is more than welcome! The SO Fresh Team would love to hear about your research utilising the SO Fresh data and in return we ask that you appropriately reference this website in your work.

Get access to the dataset

SO-FRESH L3 SSS product

Geographical coverage 180W -> 180E; 30S -> 90S
Temporal coverage 2011-02-01 to 2022-12-31
Spatial resolution 25km x 25km
Coordinates reference system EASE-SL 25km
Temporal resolution 9-day maps generated daily
Version 1.0
Source BEC FTP
ARGANS Ocean Salinity


ARGANS, is a UK-registered company with headquarters based in Plymouth UK, offices in Sophia-Antipolis and Brest, and staff located in London and Southampton.

We are specialists in satellite-based Earth Observation, remote-sensing applications and services, and geographical information systems used to map and monitor the marine, atmospheric and terrestrial environments. The team at ARGANS are also industry standard professionals in coastal charting through the application of satellite derived bathymetry.

ARGANS offers satellite mission solutions across a range of services, including development of ground segment algorithms and applications, data quality assessment and validation, or operations on behalf of space agencies, while keeping a strong scientific expertise in remote sensing science.

The company has forged strong partnerships through joining consortia both as prime and sub-contractor with UK, European and International entities: companies, research institutes, universities and individual scientific consultants.

In association with our partners:

  • BEC


    The Barcelona Expert Center (BEC) is a joint venture among Institute of Marine Sciences, CSIC (ICM), Universitat Politècnica de Catalunya (UPC) and Institute of Space Studies (IEC).

  • Southampton University

    University of Southampton

    The University of Southampton is situated in the city of Southampton, on the south coast of England. It is a founding member of the Russell Group and Worldwide Universities Network, and currently has around 25,000 students enrolled from more than 140 different countries.

User Requirement Survey for Sea Surface Salinity in the Southern Ocean

The Southern Ocean Freshwater (SO Fresh) is an ESA funded project (2021-2023) that aim at producing a dedicated satellite retrieved Sea Surface Salinity product to contribute on going scientific effort in the Southern Ocean.

SO Fresh wishes to work close with the science community. Hence, this is a four section survey and it is the first step to understand to the requirements from the Southern Ocean science community towards the production of the SSS product. - It takes about 8 min to complete the whole survey.

Thank you in advance for your time to help SO Fresh to produce the first dedicate SSS product for the Southern Ocean.

SO Fresh User Requirements survey for the Sea Surface Salinity (SSS) will be open until October 2021. Participate in the user requirement survey.

Contact our team

Contact team via form or join us in Teams