Since last September, Remote Sensing Systems (REMSS) is producing version 2.0 of the Level 2 and Level 3 Sea Surface Salinity products from SMAP. One year ago, we published in this blog a brief study on the validation of version 1.0 of the 8-day L3 SSS maps provided by REMSS (see Preliminary validation of 8-day SMAP L3 Salinity product V1.0 for more information). Now, in order to assess the improvements of this new version, we present a small comparison between these two versions of the 8-day SSS L3 maps. Part of this study was included in the V2.0 Release Notes document. The validation has been made using as reference field the 7-day global ocean 0.25-degree SSS FOAM product generated by Met Office and distributed by Copernicus.
On November 2nd, 2016, SMOS mission accomplished a new feat: the mission has now been operating for seven years!
Designed for a nominal lifetime of three years plus an extension of two years, SMOS has overcome the expectations and it is now headed for a third extension period. And the instrument is still behaving well, giving rise to new products and applications on land, ocean, and cryosphere, and even for atmospheric applications.
Congratulations to SMOS and to ESA. Long life to SMOS!
The BEC team.
The circulation in the Algerian Basin is characterized by the presence of fresh-core eddies that propagate along the coast or at distances between 100-200 km from the coast. Significant improvement in the processing of the Soil Moisture and Ocean Salinity (SMOS) data have allowed to produce, for the first time, satellite Sea Surface Salinity (SSS) maps in the Mediterranean Sea that capture the signature of Algerian eddies. SMOS data can be used to track them for long periods of time, especially during winter. SMOS SSS maps are well correlated with in situ measurements although the former has a smaller dynamical range. Despite this limitation, SMOS SSS maps capture the key dynamics of Algerian eddies allowing to retrieve velocities from SSS with the correct sign of vorticity. These results have been recently published in Geophysical Research Letters (Isern-Fontanet et al. 2016).
In a continuous effort to bring the higher quality products to our users, BEC is happy to announce that a new version of BEC SSS products (v2.00) has been put into operations.
In the new operational version, Land Sea Contamination has been mitigated by means of the empirical salinity debiasing method proposed in [Olmedo et al., 2016]. This leads to higher quality products that can be used for many different purposes. This new dataset is available at BEC products – Available variables – Sea Surface Salinity – Operational V2.0 section or by clicking here.
The Water Resources Research Group of the University of Salamanca has developed a new agricultural drought index, the so-called Soil Water Deficit Index (SWDI) , , based in soil moisture and soil parameters. Using the high resolution BEC L4 soil moisture product  as an input of the SWDI, agricultural drought maps of Zamora province (west of Spain) were derived (Fig. 1). With this product, agricultural drought conditions in the most important agricultural regions in Spain will be monitored.
The results of this research will be published soon, so stay tuned!
 Martínez-Fernández, J., González-Zamora, A., Sánchez, N., & Gumuzzio, A. (2015). “A soil water based index as a suitable agricultural drought indicator.” Journal of Hydrology, 522, 265-273.
 Martínez-Fernández, J., González-Zamora, A., Sánchez, N., Gumuzzio, A., & Herrero-Jiménez, C.M. (2016). “Satellite soil moisture for agricultural drought monitoring: Assessment of the SMOS derived Soil Water Deficit Index.” Remote Sensing of Environment, 177, 277-286.
 Piles, M., Camps, A., Vall-llossera, M., Corbella, I., Panciera, R., Rüdiger, C., Kerr, Y.H., & Walker, J. (2011). “Downscaling SMOS-Derived Soil Moisture Using MODIS Visible/Infrared Data.” IEEE Transactions on Geoscience and Remote Sensing, 49, 3156-3166.
In march 2013 an international experiment, the Salinity Processes in the Upper ocean Regional Study (SPURS), was carried out with the goal of performing a wide range of mesoscale and submesoscale measurements to understand the mechanisms of formation and permanence of the largest ocean salinity maximum in the centre of the North Atlantic subtropical gyre. Several standard and prototype instruments were used in measuring the Sea Surface Salinity (SSS) and other ocean variables. Among many activities developed during the SPURS-MIDAS cruise, the ICM contribution to SPURS, a set of new Lagrangian drifters to measure the SST and SSS were deployed. These were part of a total set of 114 similar drifters deployed during the whole experiment (Centurioni et al, 2015). Now almost three years later, three of these units are still providing data after performing a big tour around the North Atlantic.
New experimental SMOS Sea Surface Salinity (SSS) maps at high latitudes, including Arctic Ocean open water regions, have been computed at BEC using a new methodological approach that substantially reduces land-sea and RFI contamination effects, as well as other intrumental biases.
Ocean currents are a key element for the understanding of many oceanic and climatic phenomena and their knowledge is crucial for navigation and operational applications. Following the official broadening of its scope, BEC has extended its research activity towards the diagnosis of ocean surface currents from satellite observations. This new research line, led by Dr. Jordi Isern-Fontanet, is being funded through the ComFuturo program (http://comfuturo.es/proyectos/) granted by the Fundación General del CSIC (http://www.fgcsic.es/) and through the GlobCurrent project (http://www.globcurrent.org/) funded by ESA.
The SMOS-BEC (SMOS-BARCELONA EXPERT CENTER ON RADIOMETRIC CALIBRATION AND OCEAN SALINITY) was created in July 2007 by agreement between CSIC (Spanish Research Council) and UPC (Technical University of Catalonia) to enhance coordination and visibility of both institutions in their joint work in processing data from the SMOS mission. It was installed in the Centre Mediterrani d’Investigacions Marines i Ambientals (CMIMA) building, belonging to CSIC and that also hosts the Institut de Ciències del Mar (ICM) and the Unitat de Tecnologia Marina (UTM), in the Barcelona sea front. The UPC participation is made through the Passive Remote Sensing Group / Remote Sensing Lab from the Department of Signal Theory and Communications. The main CSIC actor in SMOS is the Physical and Technological Oceanography Department from ICM, together with the Earth Observation Group from the Institut de Ciències de l’Espai (ICE).
BEC scientists play a key role in the mission: Jordi Font (ICM) is the SMOS Co-Lead Investigator for ocean salinity, Ignasi Corbella (UPC) and Antonio Turiel (ICM) are members of the SMOS Quality Working Group, the BEC-UPC team is an Expert Support Laboratory to ESA for the SMOS level 1 processor definition and development, and the BEC-ICM team is an ESL for the level 2 ocean salinity processor. The BEC proposed, designed and validated the level 3 and level 4 SMOS products generated in CP34, Centro de Producción de datos SMOS de niveles 3 y 4, an additional Spanish contribution to the mission to build and operationally distribute SMOS added value products beyond the level 2 official ESA data. CP34 was operated at ESAC, the ESA establishment near Madrid that hosts the SMOS Data Processing Ground Segment, until July 2013. Then it was moved to BEC facilities, where an improved web site allows now an easy access to operational and experimental SMOS level 3 and 4 products, with user friendly format plus additional information to the international users community. …read more
Scientists at Remote Sensing Systems (RSS, http://www.remss.com), using the experience acquired with the Aquarius mission are developing the necessary algorithms to retrieve sea surface salinity from brightness temperature provided by the SMAP radiometer team.
Recently, RSS has released version 1.0 (BETA) SMAP Level 3 Ocean Surface Salinities. The data can be accessed through the RSS web site or FTP server and it is described in [Meissner et al., 2015]. Their Level 3 salinity product has worldwide coverage and correspond to 8-day and monthly averages. The 8-day average field, centered on each day, starts on April 4, 2015 and ends at November 15, 2015.
A preliminary comparison of the 8-day L3 product with ARGO profiles and the World Ocean Atlas (WOA13) climatology has been performed by BEC team over the zones indicated on the map below.