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.
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.
In addition to contribute to the build-up of the Argo system by deploying eight Argo profilers during January 2015, the One Planet, One Ocean & Pharmaton ship carried a Sea Bird SBE37-SI MicroCAT instrument to collect continuous (every minute) sea surface temperature and salinity measurements.
The R/V Sarmiento de Gamboa arrived to Ponta Delgada, Azores, on April 12, and R/V Endeavor is expected to be at Narragansett a few days later. The SPURS spring 2013 cruise is finished and both vessels have achieved the collection of an impressive amount of high resolution oceanographic data, as well as the deployment of several autonomous sampling devices. The SPURS blog (Cruises, SPURS-March 2013) has reported several aspects of the work done. It has been one month of intensive sampling of the high salinity region in the central convergence of the North Atlantic subtropical gyre. The data we have recorded will contribute understanding how this maximum is formed and sustained.
The Spanish in-situ contribution to the international SPURS (Salinity Processes in the Upper ocean Regional Study) experiment is taking place on board the R/V Sarmiento de Gamboa from March 16, 2013. A team of scientists from SMOS-BEC, plus other researchers and technicians from ICM and UTM-CSIC Barcelona, NUI Galway, LOCEAN Paris, LDEO-U. Columbia New York and U. Vigo are performing a wide range of mesoscale and submesoscale measurements to contribute understanding 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 are used in measuring sea surface salinity and other ocean variables.
The SPURS-MIDAS cruise (Las Palmas de Gran Canaria 16 March 2013 – Ponta Delgada, Açores 17 April) on board the Spanish R/V Sarmiento de Gamboa is a contribution to the SPURS experiment (Salinity Processes in the Upper ocean Regional Study) aimed at understanding the processes that drive the upper ocean dynamics and the role that salinity plays on them in the area of maximum salinity in the center of the North Atlantic subtropical gyre. The experiment is coordinated by WHOI (R. Schmitt) and sponsored by NASA (E. Lindstrom), and includes intensive field work with a large variety of state-of-the-art instrumentation, the use of satellite remotely sensed salinity information (Aquarius and SMOS), as well as dedicated numerical modeling. The SMOS BEC team is one of the participants in SPURS where it will contribute with in situ data acquisition, processing and mapping SMOS salinity data, and a regional implementation of the NEMO model with assimilative and process-based simulations to complement and analyze the processes suggested by the observations.