SMOS first data analysis for sea surface salinity determination

Abstract

International audienceSoil Moisture and Ocean Salinity (SMOS), launched on 2 November 2009, is the first satellite mission addressing sea surface salinity (SSS) measurement from space. Its unique payload is the Microwave Imaging Radiometer using Aperture Synthesis (MIRAS), a new two-dimensional interferometer designed by the European Space Agency (ESA) and operating at the L-band frequency. This article presents a summary of SSS retrieval from SMOS observations and shows initial results obtained one year after launch. These results are encouraging, but also indicate that further improvements at various data processing levels are needed and hence are currently under investigation

Large-Scale Oceanic Variability Associated with the Madden-Julian Oscillation during the CINDY/DYNAMO Field Campaign from Satellite Observations

“…Because of the recent development and advancement of microwave radiometer and the analysis technique, sea surface salinity is shown to be monitored from satellite observations [16,17,52]. A recent study [9] indicates that SSS fluctuations associated with tropical instability waves can be detected by the Aquarius measurements in the eastern tropical Pacific where a large meridional gradient of climatological SSS is located.…”

New methodology to estimate Arctic sea ice concentration from SMOS combining brightness temperature differences in a maximum-likelihood estimator

“…Developed by the European Space Agency (ESA), the SMOS's single payload, called Microwave Imaging Radiometer using Aperture Synthesis (MI-RAS), is an L-band (1.4 GHz, or 21 cm wavelength) passive interferometric radiometer that measures the electromagnetic radiation emitted by Earth's surface. The observed brightness temperature (T B ) can be related to moisture content over the soil and to salinity over the ocean surface (Kerr et al, 2010;Font et al, 2013), which can be used to infer sea ice thickness (Kaleschke et al, 2012) and snow thickness (Maaß, 2013;Maaß et al, 2015).…”

Review of the CALIMAS Team Contributions to European Space Agency’s Soil Moisture and Ocean Salinity Mission Calibration and Validation

“…Moreover, recent OTT developments have led to an improved empirical sea surface roughness model [61], which was introduced in 2011 as one of the three alternative roughness correction formulations in the SMOS operational L2OS processor (version 5.00). The scene dependent bias correction that uses the external TB calibration and that was proposed by [42] before the SMOS launch, was initially discarded for the L2OS processor (since it used non-SMOS information) and may now be reconsidered to improve the correction of the still existing residual land contamination over the ocean [13,14].…”

“…Font et al [13] provided a first analysis of SMOS data one year after launch in terms of practical problems encountered in salinity retrieval. The weak sensitivity of the brightness temperatures vs. salinity hinders the salinity retrieval, and averaging is required over 10 to 30 days to reduce random errors.…”

“…The retrieval of SSS by SMOS is a challenging task that has required (and still requires) an important effort from all the teams involved in MIRAS calibration, image reconstruction techniques, ocean forward modeling, quality control, and SSS retrievals. This effort has allowed the acquirement of the first ever satellite measurements of sea surface salinity [13] with a quality that is progressively approaching the mission requirements through successive improvements introduced in the data processing ( [14]). …”