SMOS helps discriminating water sources in cold seas

Category : L2, Ocean

Discriminating water sources from space in the Arctic Ocean: A case study for the southern Beaufort Sea using MODIS ocean color and SMOS salinity data

A recent paper by Matsuoka et al. (2016), using SMOS ESA L2 SSS, found nice correlations between the interannual variability of SMOS SSS and ocean color CDOM (see fig 1 and 2 below) in the Mackenzie river mouth. Using this region as a case study, they derive an algorithm using this two sets of data for getting reasonable fractions of river water. As stated by the authors ‘Application of this algorithm may lead to the discrimination of water sources in the surface layer of the Arctic Ocean in various environments where seawater, ice melt water, and river water are intermingled,which might be useful to improve our understanding of physical and biogeochemical processes related to each water source’.


Fig.1 : Satellite images of CDOM absorption coefficient at 443 nm [aCDOM(443),m−1] using MODIS ocean color data in July to August 2010 to 2012 (from Matsuoka et al. (2016))


Fig. 2 : Same as Fig. 1 for SMOS SSS (from Matsuoka et al. (2016)).

Atsushi Matsuoka, Marcel Babin, Emmanuel C. Devred, A new algorithm for discriminating water sources from space: A case study for the southern Beaufort Sea using MODIS ocean color and SMOS salinity data, Remote Sensing of Environment, Volume 184, October 2016, Pages 124-138, ISSN 0034-4257, (//

SMOS REPROCESSED Level 2 DATA (V6) now available

Category : Data, L1, L2, Ocean

Dear SMOS data user -

We would like to inform you that the reprocessed level 2 soil moisture and sea surface salinity data are now available on the new ESA SMOS Online Dissemination service:

This release aligns the Level 2 soil moisture and sea surface salinity data available operationally already since May 2015 with the reprocessed data archive: SMOS data users now have a complete v6 data set available.

The algorithm evolutions implemented in the v6 data set are described in the respective Algorithm Theoretical Baseline Documents (ATBDs) and in the read-me-first notes: We would like to encourage all users to familiarise themselves with the read-me-first notes before using the data.

The level 2 reprocessed data products are available on the new ESA SMOS Online Dissemination service accessible here ( The new service allows to access data by https and ftp/ftps transfer protocols for all registered ESA EO Single Sign-On (EO-SSO) users. The online service facilitates the data access with enhanced functionality for data navigation and selection by data type, acquisition time, geographical area and data format (i.e. ESA Earth Explorer (EEF) or NetCDF format).

SMOS level 1 brightness temperature data and  ECMWF auxiliary products are also available from the new ESA SMOS Online Dissemination service.

For further details on how to access the SMOS data  and how to register as ESA EO_SSO please

Kind regards

Susanne Mecklenburg


Category : CATDS, L3, Ocean

Dear  SMOS users,

All the SMOS L3 soil moisture, ocean salinity and common products, from January 2010 to April 2015, have been reprocessed. You can download those products from

a) CATDS with the usual procedure (if you do not have a password contact contact to get one) or

b) through the SIPAD interface (

Please NOTE :
- All the reprocessed products use the EASE2 grid.
- The CATDS processor’s version used is 300, which correspond to the DPGS version v620
- The reprocessed products are tagged RE04
- These reprocessed products are derived using the same algorithm as the one used in the CATDS real time processing, hence ensuring temporal continuity.
- A new RFI (radio frequency interference) probability product is available.

Very soon we will also make available 6 years of root zone soil moisture from SMOS

We appreciate your feed back so do not hesitate to contact us

Remember the SMOSDATA POLICY : The CATDS data are freely distributed. However, when using these data in a publication, we request that the following acknowledgement be given :
« These data were obtained from the « Centre Aval de Traitement des Données SMOS » (CATDS), operated for the « Centre National d’Etudes Spatiales » (CNES, France) by IFREMER (Brest, France) »

Research Engineer ‘Sea Surface Salinity retrieval from SMOS satellite measurements’

Category : L2, position opening

A research engineer position is opened at the Laboratoire d’Océanographie et du Climat – Expérimentation et Approches Numériques (LOCEAN)/ Institut Pierre Simon Laplace (IPSL), PARIS, starting as soon as possible. The position is for one year, likely renewable for 2 years.

Context :

The SMOS (Soil Moisture and Ocean Salinity) mission is the first satellite mission carrying an L-band radiometer interferometer. Since its launch, end of 2009, it acquired over 5 years of data that demonstrate the feasibility of the sea surface salinity measurement by L-band radiometry, the capability of the interferometry technique, and it opens new research topics. The LOCEAN team has been involved since 1999 in the definition of direct and inverse models applicable to SMOS. It is one of the ESA Expert Support Laboratory in charge of the definition of the algorithms used for retrieving salinity from SMOS brightness temperatures in the ESA operational chain. The selected candidate will be in charge of the improvement of existing algorithms, dealing in particular with data selection, configuration of the baysian retrieval, radiative transfer model, in close collaboration with researchers and engineers of the laboratory.

The selected candidate will join the LOCEAN IPSO (Interactions et Processus au sein de la couche de Surface Océanique) team involved in the physics of the L-band radiometry, in the satellite salinity validation and in understanding  the processes responsible for the differences observed between satellite and in situ measurements, in particular those linked  to air-sea interaction, vertical stratification and small-scale variability ( and

Work details :

- Developpement of new algorithms for improving the retrieval of the salinity from SMOS mission ; collaboration with the industrial for their implementation in the processor chain

- Relationship with other ESA expert support laboratory and with the company in charge of the evolutions and the maintenance of the processor: participation to weekly teleconference of the SMOS ESA level 2 ocean team and attending the progress meetings (3 per year). Writing of technical papers and participation to scientific papers is possible, depending on the algorithms improvements.

Required Skills:
-          Physics of satellite measurement
-          Data processing and statistics
-          Knowledge of LINUX and C
-          Matlab and/or Python
-          Autonomy and team collaborative working

Welcome Skills:
-          Optimization for huge data processing
-          Interest for environmental science

Level: Research Engineer (PhD thesis or equivalent)

Address : LOCEAN, Université Pierre et Marie Curie, Tour 45-55, 5E, 4, place Jussieu, 75005 PARIS, FRANCE.

Salary : about € 1900 net, commensurable with qualification and experience of the candidate (CNRS salary grid)

Candidates should send a statement of interest, CV and coordinates of 2 referees to  Jacqueline Boutin ( and Nicolas Martin (

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