References

HESS

Hydrology and Earth System Sciences

HESS

Hydrol. Earth Syst. Sci.

1607-7938

Copernicus Publications

Göttingen, Germany

10.5194/hess-16-423-2012

Comparing soil moisture retrievals from SMOS and ASCAT over France

Parrens

¹ Zakharova

¹ Lafont

¹ Calvet

J.-C.

¹ Kerr

² Wagner

³ Wigneron

J.-P.

⁴

CNRM-GAME, URA1357, Météo-France, CNRS, Toulouse, France

CESBIO, UMR5126, CNES/CNRS/IRD/UPS, Toulouse, France

Institute of Photogrammetry and Remote Sensing, Vienna University of Technology, Vienna, Austria

INRA, EPHYSE, Villenave d'Ornon, France

09 02 2012

16 2 423 440

2012

This work is licensed under the Creative Commons Attribution 3.0 Unported License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/3.0/

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The full text article is available as a PDF file from https://hess.copernicus.org/articles/16/423/2012/hess-16-423-2012.pdf

The first products derived over France in 2010 from the L-band brightness temperatures (Tb) measured by the SMOS (Soil Moisture and Ocean Salinity) satellite, launched in November 2009, were compared with the surface soil moisture (SSM) estimates produced by the C-band Advanced Scatterometer, ASCAT, launched in 2006 on board METOP-A. SMOS and ASCAT SSM products were compared with the simulations of the ISBA-A-gs model and with in situ measurements from the SMOSMANIA network, including 21 stations located in southern France. ASCAT tended to correlate better than SMOS with ISBA-A-gs. The significant anomaly correlation coefficients between in situ observations and the SMOS (ASCAT) product ranged from 0.23 to 0.48 (0.35 to 0.96). However, in wet conditions, similar results between the two satellite products were found. An attempt was made to derive SSM from regressed empirical logarithmic equations using a combination of SMOS Tb at different incidence angles and different polarizations, and the Leaf Area Index (LAI) modeled by ISBA-A-gs. The analysis of the intercept coefficient of the regression showed an impact of topography. A similar analysis applied to ASCAT and SMOS SSM values showed a more limited impact of topography on the intercept coefficient of the SMOS SSM product, while fewer residual geographic patterns were found for the ASCAT SSM.

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