EGU21-4796, updated on 22 Mar 2024
EGU General Assembly 2021
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.

A follow-up for the Soil Moisture and Ocean Salinity mission

Nemesio Rodriguez-Fernandez1, Yann Kerr1, Eric Anterrieu1, Francois Cabot1, Jacqueline Boutin2, Ghislain Picard3, Thierry Pellarin3, Olivier Merlin1, Maria José Escorihuela4, Ahmad Albitar1, Philippe Richaume1, Arnaud Mialon1, Baptiste Palacin5, Raquel Rodriguez Suquet5, Thierry Amiot5, Josiane Costeraste5, Frederic Vivier2, Jerome Vialard2, Louise Yu5, Thibaut Decoopman6, and the rest of the SMOS-HR team*
Nemesio Rodriguez-Fernandez et al.
  • 1CESBIO (CNES, CNRS, UT3 UPS, INRAE, IRD), 18 Av. Ed. Belin, bpi 2801, 31401 Toulouse cedex 9, France
  • 2LOCEAN, CNRS, Sorbonne Université, IRD, Muséum National d’Histoire Naturelle, Paris, France
  • 3Institut de Géosciences de l’Environnement (IGE), UGA, CNRS, G-INP, IRD, Grenoble, France
  • 4Isardsat, Parc Tecnologic Barcelona Activa, Carrer de Marie Curie, 8, 08042 Barcelona, Spain
  • 5CNES (Centre National d’Etudes Spatiales), 18 Avenue Edouard Belin, 31400 Toulouse, France
  • 6Airbus Defence and Space, 31 rue des cosmonautes, 31400 Toulouse, France
  • *A full list of authors appears at the end of the abstract

The Soil Moisture and Ocean Salinity (SMOS) satellite, launched in 2009 by ESA, has provided, for the first time, systematic passive L-band (1.4 GHz) measurements from space with a spatial resolution of ~ 40 km. SMOS data are an essential component of the ESA Climate Change Initiative (CCI) for ocean salinity and soil moisture and they are used by the CCI biomass. A specific SMOS neural network soil moisture product is assimilated operationally at the European Centre for Medium Range Weather Forecasts (ECMWF). L-band surface SM measurements have also been used to estimate root zone soil moisture, to derive drought indices, to enable food security monitoring and to improve satellite precipitation estimates. SMOS data have also been used to detect frozen soils, thin ice-sheets over the ocean and ice melting in Antarctica and Greenland.

Different studies on scientific and operational applications of L-band radiometry have shown the need of the continuity of L-band observations with an increased resolution with respect to the current generation of sensors. Resolutions from 1 km to 10 km would be a breakthrough for many applications over ocean, land and ice. One approach to obtain those resolutions could be downscaling coarse resolution data using an auxiliary dataset with higher resolution. However, using airborne data, we will show that the accuracy of the data downscaled to 1 km decreases significantly when the initial native resolution is 40 km with respect to downscaling from initial resolutions of 5-10 km. We will present two instrumental concepts to reach native resolutions of 5-10 km.

The SMOS-HR mission project, completed the Phase 0 study at the French Centre National d’Etudes Spatiales (CNES) with contributions from Airbus Defence & Space and CESBIO. The goal was to ensure the continuity of L-band measurements while increasing the spatial resolution to ~10 km, which requires a typical antenna size of ~18 meters. Taking into account the difficulty of deploying a real aperture of this size in space and the successful alternative approach used by SMOS, SMOS-HR will perform aperture synthesis using an array of 230 small antennas distributed in a cross with four 12 m arms. During the Phase A study (ongoing at CNES) a mission concept with a central carrier surrounded by a swarm of nanosatellites will also be studied.

rest of the SMOS-HR team:

Ali Khazaal, Christophe Suere, Romain Caujolle, Nicolas Jeannin, Laurent Costes

How to cite: Rodriguez-Fernandez, N., Kerr, Y., Anterrieu, E., Cabot, F., Boutin, J., Picard, G., Pellarin, T., Merlin, O., Escorihuela, M. J., Albitar, A., Richaume, P., Mialon, A., Palacin, B., Rodriguez Suquet, R., Amiot, T., Costeraste, J., Vivier, F., Vialard, J., Yu, L., and Decoopman, T. and the rest of the SMOS-HR team: A follow-up for the Soil Moisture and Ocean Salinity mission, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-4796,, 2021.


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