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143 results on '"Al-Yaari, Amen"'

1. A first assessment of satellite and reanalysis estimates of surface and root-zone soil moisture over the permafrost region of Qinghai-Tibet Plateau

Author

Xing, Zanpin, Fan, Lei, Zhao, Lin, De Lannoy, Gabrielle, Frappart, Frédéric, Peng, Jian, Li, Xiaojun, Zeng, Jiangyuan, Al-Yaari, Amen, Yang, Kun, Zhao, Tianjie, Shi, Jiancheng, Wang, Mengjia, Liu, Xiangzhuo, Hu, Guojie, Xiao, Yao, Du, Erji, Li, Ren, Qiao, Yongping, Shi, Jianzong, Wen, Jianguang, Ma, Mingguo, and Wigneron, Jean-Pierre

Published
2021
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5. Satellite-observed pantropical carbon dynamics

Author

Fan, Lei, Wigneron, Jean-Pierre, Ciais, Philippe, Chave, Jérôme, Brandt, Martin, Fensholt, Rasmus, Saatchi, Sassan S., Bastos, Ana, Al-Yaari, Amen, Hufkens, Koen, Qin, Yuanwei, Xiao, Xiangming, Chen, Chi, Myneni, Ranga B., Fernandez-Moran, Roberto, Mialon, Arnaud, Rodriguez-Fernandez, N. J., Kerr, Yann, Tian, Feng, and Peñuelas, Josep

Published
2019
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9. Satellite passive microwaves reveal recent climate-induced carbon losses in African drylands

Author

Brandt, Martin, Wigneron, Jean-Pierre, Chave, Jerome, Tagesson, Torbern, Penuelas, Josep, Ciais, Philippe, Rasmussen, Kjeld, Tian, Feng, Mbow, Cheikh, Al-Yaari, Amen, Rodriguez-Fernandez, Nemesio, Schurgers, Guy, Zhang, Wenmin, Chang, Jinfeng, Kerr, Yann, Verger, Aleixandre, Tucker, Compton, Mialon, Arnaud, Rasmussen, Laura Vang, Fan, Lei, and Fensholt, Rasmus

Published
2018
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13. Estimating High-Resolution Soil Moisture Over Mountainous Regions Using Remotely-Sensed Multispectral and Topographic Data

Author

Fan, Lei, primary, Al-Yaari, Amen, additional, Frappart, Frederic, additional, Peng, Jian, additional, Wen, Jianguang, additional, Xiao, Qing, additional, Jin, Rui, additional, Li, Xiaojun, additional, Liu, Xiangzhuo, additional, Wang, Mengjia, additional, Chen, Xiuzhi, additional, Zhao, Lin, additional, Ma, Mingguo, additional, and Wigneron, Jean-Pierre, additional

Published
2022
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15. Alternate Inrae-Bordeaux VOD Indices from SMOS, AMSR2 and ASCAT: Overview of Recent Developments

Author

Wigneron, Jean-Pierre, primary, Li, Xiaojun, additional, Liu, Xiangzhuo, additional, Wang, Mengjia, additional, Frappart, Frederic, additional, Fan, Lei, additional, Al-Yaari, Amen, additional, Fernandez-Moran, Roberto, additional, Ma, Hongliang, additional, Ygorra, Bertrand, additional, Xing, Zanping, additional, Masson, Erwan Le, additional, Moisy, Christophe, additional, Yang, Hui, additional, Baghdadi, Nicolas, additional, and Ciais, Philippe, additional

Published
2021
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17. Interannual Variability of Biomass (SMOS Vegetation Optical Depth) Over the Contiguous United States

Author

Al-Yaari, Amen, primary, Wigneron, Jean-Pierre, additional, Ducharne, Agnes, additional, Frappart, Frederic, additional, Li, Xiaojun, additional, Liu, Xiangzhuo, additional, Wang, Mengjia, additional, Fan, Lei, additional, Ma, Hongliang, additional, Xing, Zanping, additional, Fernandez-Moran, Robert, additional, and Moisy, Christophe, additional

Published
2021
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19. Multivariable evaluation of land surface processes in forced and coupled modes reveals new error sources to the simulated water cycle in the IPSL (Institute Pierre Simon Laplace) climate model

Author

Mizuochi, Hiroki, primary, Ducharne, Agnès, additional, Cheruy, Frédérique, additional, Ghattas, Josefine, additional, Al-Yaari, Amen, additional, Wigneron, Jean-Pierre, additional, Bastrikov, Vladislav, additional, Peylin, Philippe, additional, Maignan, Fabienne, additional, and Vuichard, Nicolas, additional

Published
2021
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22. Supplementary material to "Multi-variable evaluation of land surface processes in forced and coupled modes reveals new error sources to the simulated water cycle in the IPSL climate model"

Author

Mizuochi, Hiroki, primary, Ducharne, Agnes, additional, Cheruy, Frédérique, additional, Ghattas, Josefine, additional, Al-Yaari, Amen, additional, Wigneron, Jean-Pierre, additional, Peylin, Philippe, additional, Maignan, Fabienne, additional, and Vuichard, Nicolas, additional

Published
2020
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24. Asymmetric responses of ecosystem productivity to rainfall anomalies vary inversely with mean annual rainfall over the conterminous United States

Author

Al‐Yaari, Amen, primary, Wigneron, Jean‐Pierre, additional, Ciais, Philippe, additional, Reichstein, Markus, additional, Ballantyne, Ashley, additional, Ogée, Jerome, additional, Ducharne, Agnès, additional, Swenson, Jennifer J., additional, Frappart, Frédéric, additional, Fan, Lei, additional, Wingate, Lisa, additional, Li, Xiaojun, additional, Hufkens, Koen, additional, and Knapp, Alan K., additional

Published
2020
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25. Global Monitoring of the Vegetation Dynamics from the Vegetation Optical Depth (VOD): A Review

Author

Frappart, Frédéric, primary, Wigneron, Jean-Pierre, additional, Li, Xiaojun, additional, Liu, Xiangzhuo, additional, Al-Yaari, Amen, additional, Fan, Lei, additional, Wang, Mengjia, additional, Moisy, Christophe, additional, Le Masson, Erwan, additional, Aoulad Lafkih, Zacharie, additional, Vallé, Clément, additional, Ygorra, Bertrand, additional, and Baghdadi, Nicolas, additional

Published
2020
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26. Negative asymmetry response of ecosystem productivity to annual rainfall anomalies over the conterminous U.S during the 2010 -2018 period

Author

Al-Yaari, Amen, primary, Wigneron, Jean-Pierre, additional, Ciais, Philippe, additional, Knapp, Alan, additional, Reichstein, Markus, additional, Ogee, Jerome, additional, Wingate, Lisa, additional, Carvalhais, Nuno, additional, Lei, Fan, additional, Hufkens, Koen, additional, Chave, Jerome, additional, Frappart, Frédéric, additional, Swenson, Jennifer, additional, and Ducharne, Ducharne, additional

Published
2020
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28. Comparison of surface soil moisture simulated by the orchidee land surface model with multi-source global satellite products

Author

Mizuochi, Hiroki, Al-Yaari, Amen, Wigneron, Jean-Pierre, Ducharne, Agnès, Université de Tsukuba = University of Tsukuba, Interactions Sol Plante Atmosphère (UMR ISPA), Institut National de la Recherche Agronomique (INRA)-Ecole Nationale Supérieure des Sciences Agronomiques de Bordeaux-Aquitaine (Bordeaux Sciences Agro), Metis, Centre National de la Recherche Scientifique (CNRS), and IEEE Geoscience and Remote Sensing Society (GRSS). USA.

Subjects
[SDV]Life Sciences [q-bio], ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2019

29. An evaluation of SMOS L-band vegetation optical depth (L-VOD) data sets:high sensitivity of L-VOD to above-ground biomass in Africa

Author

Rodríguez-Fernández, Nemesio J., Mialon, Arnaud, Mermoz, Stephane, Bouvet, Alexandre, Richaume, Philippe, Al Bitar, Ahmad, Al-Yaari, Amen, Brandt, Martin Stefan, Kaminski, Thomas, Le Toan, Thuy, Kerr, Yann H., and Wigneron, Jean-Pierre

Abstract

The vegetation optical depth (VOD) measured at microwave frequencies is related to the vegetation water content and provides information complementary to visible/infra-red vegetation indices. This study is devoted to the characterisation of a new VOD data set obtained from SMOS (Soil Moisture and Ocean Salinity) satellite observations at L-band (1.4 GHz). Three different SMOS L-band VOD (L-VOD) data sets (SMOS Level 2, Level 3 and SMOS-IC) were compared with data sets on tree height, visible/infra-red indexes (NDVI, EVI), cumulated precipitation, and above ground biomass (AGB) for the African continent. For all relationships, SMOS-IC showed the lowest dispersion and highest correlation. Overall, we found a strong (R > 0.85) correlation with no clear sign of saturation between L-VOD and four AGB data sets. The relationship linking L-VOD to tree height (R = 0.87) and Baccini's AGB (R = 0.94) was strong and linear. The relationships between L-VOD and three other AGB data sets were linear per land cover class, but with a changing slope depending on the land cover type. For low vegetation classes, the annual mean of L-VOD spans a range from 0 to 0.7 and it is linearly correlation with the amount of the average annual precipitations. SMOS L-VOD showed a higher sensitivity to AGB as compared to NDVI and K/X/C-VOD (VOD measured, respectively, at 19, 10.7, and 6.9 GHz). The results showed that although the spatial resolution of L-VOD is coarse (~ 40 km), the high temporal frequency and sensitivity to AGB makes SMOS L-VOD a very promising index for large scale monitoring of the vegetation status, in particular biomass.

Published
2018

30. The aqui network: soil moisture sites in the 'Les Landes' forest and graves vineyards (Bordeaux Aquitaine Region, France)

Author

Wigneron, Jean-Pierre, Dayau, Sylvia, Kruszewski, Alain, Aluome, Christelle, Guillot-Ehret, Marie, Al-Yaari, Amen, Fan, Lei, Güven, Serhat, Chipeaux, Christophe, Moisy, Christophe, Guyon, Dominique, Loustau, Denis, Interactions Sol Plante Atmosphère (UMR ISPA), Institut National de la Recherche Agronomique (INRA)-Ecole Nationale Supérieure des Sciences Agronomiques de Bordeaux-Aquitaine (Bordeaux Sciences Agro), and Y?ld?z Technical University

Subjects
Hydrology, Radiometer, 010504 meteorology & atmospheric sciences, Water table, [SDV]Life Sciences [q-bio], 0211 other engineering and technologies, 02 engineering and technology, 15. Life on land, 01 natural sciences, Vineyard, Remote sensing (archaeology), Moisture measurement, [SDE]Environmental Sciences, Environmental science, Water content, 021101 geological & geomatics engineering, 0105 earth and related environmental sciences
Abstract

International audience; INRA (National Institute of Agricultural Research) has set up the AQUI network in the Bordeaux-Aquitaine region (southwestern France) in the framework of the SMOS cal/val activities. This network includes sites of in situ measurements which have been equipped with sensors measuring soil moisture (SM) and temperature, at various depths, and the height of the groundwater table. Four sites were installed in the Les Landes forest, which is one of the largest coniferous forests in Europpe, and one site was installed close to vineyard fields of the Bordeaux Graves region. First results of the evaluation of the SM data retrieved from the L-band SMOS and SMAP passive microwave radiometers over the AQUI network are presented. The AQUI network was included in ISMN (International Soil moisture Network) in 2018.

Published
2018

31. Le nouveau produit Smos-IC : humidité du sol et indice de végétation L-VOD

Author

Wigneron, Jean-Pierre, Mialon, Arnaud, Al-Yaari, Amen, Kerr, Yann H., Interactions Sol Plante Atmosphère (UMR ISPA), Institut National de la Recherche Agronomique (INRA)-Ecole Nationale Supérieure des Sciences Agronomiques de Bordeaux-Aquitaine (Bordeaux Sciences Agro), Centre d'études spatiales de la biosphère (CESBIO), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), and Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)

Subjects
[SDV]Life Sciences [q-bio], ComputingMilieux_MISCELLANEOUS
Abstract

National audience

Published
2018

32. After Almost 10 Years in Orbit: First Glance at Synergisms and New Results

Author

Kerr, Yann H., primary, Al-Yaari, Amen, additional, Fan, Lei, additional, Wigneron, Jean-Pierre, additional, Mialon, Arnaud, additional, Al Bitar, Ahmad, additional, Bousquet, Emma, additional, Richaume, Philippe, additional, Rodriguez-Fernandez, Nemesio, additional, Cabot, Francois, additional, and Miernecki, Maciej, additional

Published
2019
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34. Multi-variable evaluation of land surface processes in forced and coupled modes reveals new error sources to the simulated water cycle in the IPSL climate model.

Author

Hiroki Mizuochi, Ducharne, Agnes, Cheruy, Frédérique, Ghattas, Josefine, Al-Yaari, Amen, Wigneron, Jean-Pierre, Peylin, Philippe, Maignan, Fabienne, and Vuichard, Nicolas

Abstract

Evaluating land surface models (LSMs) using available observations is important to understand the potential and limitations of current Earth system models in simulating water- and carbon-related variables. To reveal the error sources of a land surface model (LSM), four essential climate variables have been evaluated in this paper (i.e., surface soil moisture, evapotranspiration, leaf area index, and surface albedo) via simulations with IPSL LSM ORCHIDEE (Organizing Carbon and Hydrology in Dynamic Ecosystems), particularly focusing on the difference between (i) forced simulations with atmospheric forcing data (WATCH-Forcing-DATA-ERA-Interim: WFDEI) and (ii) coupled simulations with the IPSL atmospheric general circulation model. Results from statistical evaluation using satellite- and ground-based reference data show that ORCHIDEE is well equipped to represent spatiotemporal patterns of all variables in general. However, further analysis against various landscape/meteorological factors (e.g., plant functional type, slope, precipitation, and irrigation) suggests potential uncertainty relating to freezing/snowmelt, temperate plant phenology, irrigation, as well as contrasted responses between forced and coupled mode simulations. The biases in the simulated variables are amplified in coupled mode via surface-atmosphere interactions, indicating a strong link between irrigation-precipitation and a relatively complex link between precipitation-evapotranspiration that reflects the hydrometeorological regime of the region (energy-limited or water-limited) and snow-albedo feedback in mountainous and boreal regions. The different results between forced and coupled modes imply the importance of model evaluation under both modes to isolate potential sources of uncertainty in the model. [ABSTRACT FROM AUTHOR]

Published
2020
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35. SMOS-IC: an alternative SMOS soil moisture and 3 vegetation optical depth product

Author

Fernandez-Moran, Roberto, Al-Yaari, Amen, Mialon, Arnaud, Mahmoodi, Ali, Al Bitar, Ahmad, De Lannoy, Gabrielle, López-Baeza, Ernesto, Kerr, Yann, and Wigneron, Jean-Pierre

Subjects
SMOS, L-band, Level 3, ECMWF, SMOS-IC, soil moisture, vegetation optical depth, MODIS, NDVI
Abstract

The main goal of the Soil Moisture and Ocean Salinity (SMOS) mission over land surfaces is the production of global maps of soil moisture (SM) and vegetation optical depth (τ) based on multi-angular brightness temperature (TB) measurements at L-band. The operational SMOS Level 2 and Level 3 soil moisture algorithms account for different surface effects, such as vegetation opacity and soil roughness at 4 km resolution, in order to produce global retrievals of SM and τ. In this study, we present an alternative SMOS product which was developed by INRA (Institut National de la Recherche Agronomique) and CESBIO (Centre d’Etudes Spatiales de la BIOsphère). This SMOS-INRA-CESBIO (SMOS-IC) product provides daily SM and τ at the global scale and differs from the operational SMOS Level 3 (SMOSL3) product in the treatment of retrievals over heterogeneous pixels. Specifically, SMOS-IC is much simpler and does not account for corrections associated to the antenna pattern and the complex SMOS viewing angle geometry. It considers pixels as homogeneous to avoid uncertainties and errors linked to inconsistent auxiliary data sets which are used to characterize the pixel heterogeneity in the SMOS L3 algorithm. SMOS-IC also differs from the current SMOSL3 product (Version 300, V300) in the values of the effective vegetation scattering albedo (ω) and soil roughness parameters. An inter-comparison is presented in this study based on the use of ECMWF (European Center for Medium range Weather Forecasting) SM outputs and NDVI (Normalized Difference Vegetation Index) from MODIS (Moderate-Resolution Imaging Spectroradiometer). A 6 year (2010-2015) inter-comparison of the SMOS products SMOS-IC and SMOSL3 SM (V300) with ECMWF SM yielded higher correlations and lower ubRMSD (unbiased root mean square difference) for SMOS-IC over most of the pixels. In terms of τ, SMOS-IC τ was found to be better correlated to MODIS NDVI in most regions of the globe, with the exception of the Amazonian basin and of the northern mid-latitudes.

Published
2017

36. Rebuilding long time series global soil moisture products using the neural network adopting the microwave vegetation index (Correction)

Author

Yao, Panpan, Shi, Jiancheng, Zhao, Tianjie, Lu, Hui, Al Yaari, Amen, University of Chinese Academy of Sciences, State Key Laboratory of Remote Sensing Science, Institute of Remote Sensing and Digital Earth, Chinese Academy of Sciences [Changchun Branch] (CAS), The Joint Center for Global Change Studies, Interactions Sol Plante Atmosphère (ISPA), Ecole Nationale Supérieure des Sciences Agronomiques de Bordeaux-Aquitaine (Bordeaux Sciences Agro)-Institut National de la Recherche Agronomique (INRA), Interactions Sol Plante Atmosphère (UMR ISPA), and Institut National de la Recherche Agronomique (INRA)-Ecole Nationale Supérieure des Sciences Agronomiques de Bordeaux-Aquitaine (Bordeaux Sciences Agro)

Subjects
analyse de données, remote sensing, télédétection, [SDE.MCG]Environmental Sciences/Global Changes, data analysis, Signal and Image processing, Traitement du signal et de l'image, indice de végétation, Milieux et Changements globaux, radiometer, radiomètre, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, Physics::Geophysics
Abstract

Correction de l'article : "Rebuilding Long Time Series Global Soil Moisture Products Using the Neural Network Adopted the Microwave Vegetation Index" (Remote Sensing, vol 9, pg 35, 2017); Rebuilding long time series global soil moisture products using the neural network adopting the microwave vegetation index (Correction)

Published
2017

37. An evaluation of SMOS L-band vegetation optical depth (L-VOD) data sets: high sensitivity of L-VOD to above-ground biomass in Africa

Author

Rodríguez-Fernández, Nemesio J., primary, Mialon, Arnaud, additional, Mermoz, Stephane, additional, Bouvet, Alexandre, additional, Richaume, Philippe, additional, Al Bitar, Ahmad, additional, Al-Yaari, Amen, additional, Brandt, Martin, additional, Kaminski, Thomas, additional, Le Toan, Thuy, additional, Kerr, Yann H., additional, and Wigneron, Jean-Pierre, additional

Published
2018
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38. Satellite‐Observed Major Greening and Biomass Increase in South China Karst During Recent Decade

Author

Brandt, Martin, primary, Yue, Yuemin, additional, Wigneron, Jean Pierre, additional, Tong, Xiaowei, additional, Tian, Feng, additional, Jepsen, Martin Rudbeck, additional, Xiao, Xiangming, additional, Verger, Aleixandre, additional, Mialon, Arnaud, additional, Al‐Yaari, Amen, additional, Wang, Kelin, additional, and Fensholt, Rasmus, additional

Published
2018
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40. The high sensitivity of SMOS L-Band vegetation optical depth to biomass

Author

Rodríguez-Fernández, Nemesio J., primary, Mialon, Arnaud, additional, Mermoz, Stephane, additional, Bouvet, Alexandre, additional, Richaume, Philippe, additional, Al Bitar, Ahmad, additional, Al-Yaari, Amen, additional, Brandt, Martin, additional, Kaminski, Thomas, additional, Le Toan, Thuy, additional, Kerr, Yann H., additional, and Wigneron, Jean-Pierre, additional

Published
2018
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41. Supplementary material to "The high sensitivity of SMOS L-Band vegetation optical depth to biomass"

Author

Rodríguez-Fernández, Nemesio J., primary, Mialon, Arnaud, additional, Mermoz, Stephane, additional, Bouvet, Alexandre, additional, Richaume, Philippe, additional, Al Bitar, Ahmad, additional, Al-Yaari, Amen, additional, Brandt, Martin, additional, Kaminski, Thomas, additional, Le Toan, Thuy, additional, Kerr, Yann H., additional, and Wigneron, Jean-Pierre, additional

Published
2018
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43. Extreme events monitoring from space

Author

Kerr, Yann, Al Bitar, Ahmad, Mahmoodi, Ali, Richaume, Philippe, Al Yaari, Amen, Wigneron, Jean-Pierre, Centre d'études spatiales de la biosphère (CESBIO), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Interactions Sol Plante Atmosphère (ISPA), Institut National de la Recherche Agronomique (INRA)-Ecole Nationale Supérieure des Sciences Agronomiques de Bordeaux-Aquitaine (Bordeaux Sciences Agro), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), and Interactions Sol Plante Atmosphère (UMR ISPA)

Subjects
analyse de données, interprétation des résultats, [SDE.MCG]Environmental Sciences/Global Changes, data analysis, projet smos, donnée satellite, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing
Abstract

The SMOS (Soil Moisture and Ocean Salinity) satellite was successfully launched in November 2009. This ESA led mission for Earth Observation is dedicated to provide soil moisture over continental surface (with an accuracy goal of 0.04 m3/m3), vegetation water content over land, and ocean salinity. These geophysical features are important as they control the energy balance between the surface and the atmosphere. Their knowledge at a global scale is of interest for climatic and weather researches, and in particular in improving model forecasts. The Soil Moisture and Ocean Salinity mission has now been collecting data for 6 years. The whole data set has just been reprocessed (Version 620 for levels 1 and 2 and version 3 for level 3 CATDS). After 6 years it seems important to start using data for having a look at anomalies and see how they can relate to large scale events The purpose of this communication is to present the mission results after more than six years in orbit in a climatic trend perspective, as through such a period anomalies can be detected. Thereby we benefit from consistent datasets provided through the latest reprocessing using most recent algorithm enhancements. Using the above mentioned products it is possible to follow large events such as the evolution of the droughts in North America, or water fraction evolution over the Amazonian basin. In this occasion we will focus on the analysis of SMOS and ancillary products anomalies to reveal two climatic trends, the temporal evolution of water storage over the Indian continent in relation to rainfall anomalies, and the global impact of El Nino types of events on the general water storage distribution. This presentation shows in detail the use of long term data sets of L-band microwave radiometry in two specific cases, namely droughts and water budget over a large basin. Several other analyses are under way currently. Obviously, vegetation water content, but also dielectric constant, are carrying a wealth of information and some interesting perspectives will be presented.

Published
2016

44. SOIL moisture data intercomparison

Author

Kerr, Yann H., Rodriguez‐Fernandez, Nemesio, Al Yaari, Amen, Parrens, Marie, Molero, Beatriz, Mahmoodi, Ali, Mialon, Arnaud, Richaume, Philippe, Bindlish, Rajat, Mecklenburg, Susanne, Wigneron, Jean-Pierre, Centre d'études spatiales de la biosphère (CESBIO), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Interactions Sol Plante Atmosphère (ISPA), Institut National de la Recherche Agronomique (INRA)-Ecole Nationale Supérieure des Sciences Agronomiques de Bordeaux-Aquitaine (Bordeaux Sciences Agro), United States Department of Agriculture, ESRIN, European Space Agency (ESA), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Interactions Sol Plante Atmosphère (UMR ISPA), and ESA Centre for Earth Observation (ESRIN)

Subjects
[SDV]Life Sciences [q-bio], projet smos, donnée satellite
Abstract

The Soil Moisture and Ocean Salinity satellite (SMOS) was launched in November 2009 and started delivering data in January 2010. Subsequently, the satellite has been in operation for over 6 years while the retrieval algorithms from Level 1 to Level 2 underwent significant evolutions as knowledge improved. Other approaches for retrieval at Level 2 over land were also investigated while Level 3 and 4 were initiated. In this présentation these improvements are assessed by inter-comparisons of the current Level 2 (V620) against the previous version (V551) and new products either using neural networks or Level 3. In addition a global evaluation of different SMOS soil moisture (SM) products is performed comparing products with those of model simulations and other satellites (AMSR E/ AMSR2 and ASCAT). Finally, all products were evaluated against in situ measurements of soil moisture (SM). The study demonstrated that the V620 shows a significant improvement (including those at level1 improving level2)) with respect to the earlier version V551. Results also show that neural network based approaches can yield excellent results over areas where other products are poor. Finally, global comparison indicates that SMOS behaves very well when compared to other sensors/approaches and gives consistent results over all surfaces from very dry (African Sahel, Arizona), to wet (tropical rain forests). RFI (Radio Frequency Interference) is still an issue even though detection has been greatly improved while RFI sources in several areas of the world are significantly reduced. When compared to other satellite products, the analysis shows that SMOS achieves its expected goals and is globally consistent over different eco climate regions from low to high latitudes and throughout the seasons.

Published
2016

45. Evaluation of three different data fusion approaches that uses satellite soil moisture from different passive microwave sensors to construct one consistent climate record

Author

Van der Schalie, Robin, De Jeu, Richard, Kerr, Yann, Wigneron, Jean-Pierre, Rodríguez-Fernández, Nemesio, Al Yaari, Amen, Drusch, Matthias, Mecklenburg, Susanne, Dolman, Han, Faculty of Earth and Life Sciences, VU University, Space Technology Center, Centre d'études spatiales de la biosphère (CESBIO), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Interactions Sol Plante Atmosphère (ISPA), Institut National de la Recherche Agronomique (INRA)-Ecole Nationale Supérieure des Sciences Agronomiques de Bordeaux-Aquitaine (Bordeaux Sciences Agro), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA), VU University Amsterdam, Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Interactions Sol Plante Atmosphère (UMR ISPA), and Vrije universiteit = Free university of Amsterdam [Amsterdam] (VU)

Subjects
analyse de données, remote sensing, capteur smos, télédétection, data analysis, capteur satellite, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, soil moisture and ocean salinity
Abstract

Evaluation of three different data fusion approaches that uses satellite soil moisture from different passive microwave sensors to construct one consistent climate record. European Geosciences Union General Assembly 2016

Published
2016

46. First application of regression analysis to retrieve soil moisture from SMAP brightness temperature observations consistent with SMOS soil moisture

Author

Al Yaari, Amen, Wigneron, Jean-Pierre, Kerr, Yann, Rodriguez-Fernandez, Nemesio, O'Neill, Peggy, Jackson, Thomas, De Lannoy, Gabrielle, Al Bitar, Ahmad, Mialon, Arnaud, Richaume, Philippe, Yueh, Simon, Interactions Sol Plante Atmosphère (UMR ISPA), Institut National de la Recherche Agronomique (INRA)-Ecole Nationale Supérieure des Sciences Agronomiques de Bordeaux-Aquitaine (Bordeaux Sciences Agro), Department of Earth and Environmental Sciences [Leuven] (EES), Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), United States Department of Agriculture, Jet Propulsion Laboratory (JPL), California Institute of Technology (CALTECH)-NASA, and Interactions Sol Plante Atmosphère (ISPA)

Subjects
remote sensing, télédétection, modèle de transfert radiatif, projet smos, équation de régression, donnée satellite, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing
Abstract

Two dedicated soil moisture (SM) spaceborne missions, ESA’s Soil Moisture and Ocean Salinity (SMOS) and NASA’s Soil Moisture Active Passive (SMAP) satellites, were launched in 2009 and 2015, respectively. Both satellites have been providing microwave brightness temperature (TB) observations and SM retrievals at L-band since then (Entekhabi et al., 2010; Kerr et al., 2012). A recent study demonstrated the efficiency of physically-based multiple-linear regression equations (Wigneron et al., 2004) to retrieve SM from AMSR-E TB observations. The regression equations were derived analytically from the radiative transfer model. The purpose of that initial study was to extend the SMOS SM product into the past i.e., 2003-2009, using AMSR-E TB observations. The current study follows the same strategy to retrieve SM from SMAP TB observations with a purpose to extend the SMOS SM product into the future at the global scale. Regression coefficients were calibrated using SMOS horizontal and vertical TB observations and SM level 3 (SMOSL3 as a training data), over the 2013 - 2014 period. Based on these calibrated coefficients, global SM maps were produced from the SMAP TB observations during the 31/03-08/09/2015 period (referred here to as SMAP-reg). The SM data set obtained from SMAP TBs using the regression equations has been compared to the SMAP SM dataset computed withthe single channel algorithm and both exhibit the same temporal dynamics. For instance, figure 1 shows the (Pearson) correlation coefficient (R) between SMAP-reg and SMAP original SM over 31/03-08/09/2015. A remarkable agreement, R (mostly > 0.8), was obtained between the SMAP-reg and SMAP original SM products.Ongoing evaluations of the SMAP-reg SM product, with comparison to the SMAP original SM, against the global MERRA-Land SM simulations and in situ measurements will be presented. The main interest in the SMAP-reg SM product is that it is fully consistent with the SMOS Level 3 SM product. One of the key remaining tasks is toensure the consistent relative calibration between SMOS and SMAP TBs.

Published
2016

47. SMOS mission after 6 years in space: where are we?

Author

Kerr, Yann, Mecklenburg, Susanne, Delwart, Steven, Boutin, Jacqueline, Ferrazzoli, Paolo, Font, Jordi, Mahmoodi, Ali, Reul, Nicolas, Richaume, Philippe, Mialon, Arnaud, Al Yaari, Amen, Bircher, Simone, Wigneron, Jean-Pierre, Centre d'études spatiales de la biosphère (CESBIO), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), ESA Centre for Earth Observation (ESRIN), European Space Agency (ESA), Interactions et Processus au sein de la couche de Surface Océanique (IPSO), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Università degli Studi di Roma Tor Vergata [Roma], Department of Physical and Technological Oceanography, Institut de Ciències del Mar, Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Interactions Sol Plante Atmosphère (UMR ISPA), Institut National de la Recherche Agronomique (INRA)-Ecole Nationale Supérieure des Sciences Agronomiques de Bordeaux-Aquitaine (Bordeaux Sciences Agro), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), ESRIN, Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN), Interactions Sol Plante Atmosphère (ISPA), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Agence Spatiale Européenne = European Space Agency (ESA), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Institute of Marine Sciences / Institut de Ciències del Mar [Barcelona] (ICM), and Consejo Superior de Investigaciones Científicas [Madrid] (CSIC)

Subjects
remote sensing, télédétection, projet smos, diffusion des résultats, capteur satellite, température de brillance, donnée satellite, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing
Abstract

The SMOS (Soil Moisture and Ocean Salinity) satellite was successfully launched in November 2009. This ESA led mission for Earth Observation is dedicated to provide soil moisture over continental surface (with an accuracy goal of 0.04 m3/m3) vegetation water content over land and ocean salinity. These geophysical features are important as they control the energy balance between the surface and the atmosphere. Their knowledge at a global scale is of interest for climatic and weather researches in particular in improving models forecasts. The SMOS instrument measures the passive microwave emission of the Earth surface at a frequency of 1,4 GHz (L-band). The instrument is an interferometer and provides brightness temperatures with an average resolution of 40 km, at several angles and dual polarizations. Data are acquired at two times in a day at 6 am and 18 pm (local time) and insure a complete coverage of the Earth surface in 3 days with a sampling of 15 km. The main products of the mission are of course Soil Moisture and Sea Surface salinity, but also vegetation opacity (directly related to water content) of vegetation covers including forests, surface dielectric constant for level two but also brightness temperatures at the surface, strong winds, root zone soil moisture and RFI (radio frequency interferences) maps. From Level 2 SMOS data several groups have started making new products several of them being either operational or on the verge of being such. We will show some of them or refer to related presentations. They include freeze defreeze (FMI), thin sea ice (Klimat Center Hamburg), near real time brightness temperatures and soon soil moisture (ECMWF), root zone soil moisture and drought indices (USDA and CESBIO). We are also working on more elaborate products such as water fractions, flood risk indices, improved precipitation with use of assimilated SMOS data, etc. The focus in this presentation will be given to the latter new science products. The purpose of this communication is to present the mission results after almost 6 years in orbit and a major re-processing as well as some outstanding results already obtained. A special attention will be devoted to level 2 products and to the retrieval quality improvements from version 3 (at launch) to the current version 620.

Published
2016

48. Testing simple local regression equations to derive long‐term global soil moisture datasets from passive microwave observations

Author

Al Yaari, Amen, Wigneron, Jean-Pierre, Kerr, Yann, De Jeu, Richard, Rodriguez‐Fernandez, Nemesio, Van der Schalie, Robin, Dolman, Han, Drusch, Matthias, Mecklenburg, Susanne, Interactions Sol Plante Atmosphère (UMR ISPA), Institut National de la Recherche Agronomique (INRA)-Ecole Nationale Supérieure des Sciences Agronomiques de Bordeaux-Aquitaine (Bordeaux Sciences Agro), Centre d'études spatiales de la biosphère (CESBIO), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), University of Amsterdam [Amsterdam] (UvA), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA), ESA Centre for Earth Observation (ESRIN), European Space Research Institute (ESRIN). ITA., Interactions Sol Plante Atmosphère (ISPA), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), and Université Fédérale Toulouse Midi-Pyrénées-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing
Abstract

The European Space Agency's Water Cycle Multimission Observation Strategy (WACMOS) was set up in 2010‐2012 and supported by the Support To Science Element (STSE) program. Within WACMOS first long term soil moisture (SM) data records from passive and active microwave data have been developed. In January 2012 the ESA Climate Change Initiative (CCI) SM program started and refined the SM products obtained during the preliminary WACMOS project. In June 2012, the first long term SM datasets have been made public available through the ESA CCI portal (Su et al., 2010) and in July 2014 the second version was available also on the same portal. This product was computed by merging surface SM (SSM) data sets retrieved from several microwave sensors in an attempt to produce the most complete and consistent long‐term time series of SM (1978‐2013) (http://www.esa‐cci.org/)(Liu et al., 2012). Two dedicated SM spaceborne missions, the Soil Moisture and Ocean Salinity (SMOS) and Soil Moisture Active/Passive (SMAP) satellites, were launched just recently, and therefore not yet considered for the CCI product. SMOS is an innovative in space technology that has been providing multi‐angular microwave brightness temperatures TB observations at L‐band since 2010 (Kerr et al., 2012). The ESA established a passive microwave SSM fusion study to investigate the inclusion of SMOS SSM in a long‐term SM datasets. For this purpose, three approaches have been selected: the Land Parameter Retrieval Model (LPRM) algorithm (Owe et al., 2001; Owe et al., 2008; Van der Schalie et al., 2015), neural networks (Rodriguez‐Fernandez et al., 2014; Rodríguez‐Fernández et al., 2015), and local statistical regressions (Wigneron et al., 2004). The present study addresses only the local regressions, as the first two methods are addressed by other groups. Objectives: The main objectives of this study are to: (i) test a physically based local regression method to retrieve SSM from the AMSR‐E TB observations at the global scale, (ii) extend the SMOS SSM into the past (2003‐2009), (iii) compare the quality of this product to the other SM datasets produced from the two other approaches, with reference to modelled SSM datasets and in situ measurements at both global and local scales. Methods: Wigneron et al. (2004) and Saleh et al. (2006) have developed and evaluated physically‐based regression equations between the SSM and microwave reflectivity (i.e. one minus emissivity) derived analytically from the radiative transfer model (τ‐ω model) (Mo et al., 1982; Wigneron et al., 1995). More specifically, this study investigated the use of these local regression methods to retrieve SSM based on a combination of passive microwave remote sensing observations from the Advanced Microwave Scanning Radiometer (AMSR‐E; 2003 ‐ Sept. 2011) and the SMOS sensors. Regression coefficients were calibrated “locally” over each pixel using AMSR‐E horizontal and vertical TB observations and SMOS level 3 SM (SMOSL3; as a training data). This calibration process was carried out over the June 2010 ‐ Sept. 2011 period, over which both SMOS and AMSRE observations coincide. Results and conclusion: Based on these calibrated coefficients, global SSM maps were computed from the AMSR‐E TB observations during the 2003‐2011 period (referred here to as AMSR‐reg). The regression quality was assessed by evaluating the AMSR‐reg SSM maps against the SMOSL3 SSM products over the period of calibration, in terms of correlations (R) and Root Mean Square Error (RMSE). A good agreement, R (mostly > 0.75) and RMSE (mostly < 0.04 m3/m3), was obtained between the AMSR‐reg and SMOSL3 SSM products particularly over Australia, central USA, central Asia, and the Sahel. AMSR‐reg retrievals were compared to the original AMSR‐E SSM retrievals derived from the Land Parameter Retrieval Model (AMSR‐LPRM), against two kinds of reference SSM: (i) global MERRA‐Land SSM simulations (2003 ‐ 2009) and (ii) in situ measurements (2008‐2009). The results demonstrated that both AMSR‐reg and AMSR‐LPRM (better) successfully captured the temporal dynamics of the used SM references in terms of correlation values. The AMSR‐reg was more consistent with MERRA‐land than AMSR‐LPRM in terms of unbiased RMSE (unbRMSE) particularly over high latitude regions with a global average of unbRMSE of 0.059 and 0.098 m3/m3, respectively. In conclusion, the statistical regression appears to be a promising approach for merging the SSM data sets retrieved from both AMSR‐E and SMOS in the framework of the ESA CCI project.

Published
2015

49. SMOS the water cycle mission : an overview, Earth Observation for water cycle science

Author

Kerr, Yann H., Delwart, Steven, Mecklenburg, Susanne, Boutin, Jacqueline, Ferrazzoli, Patricia, Mahmoodi, Ali, Al-Yaari, Amen, Mialon, Arnaud, Richaume, Philippe, Wigneron, Jean-Pierre, Bircher, Simone, Rodriguez‐fernandez, Nemesio, Reul, Nicolas, Centre d'études spatiales de la biosphère (CESBIO), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), ESA Centre for Earth Observation (ESRIN), European Space Agency (ESA), Interactions et Processus au sein de la couche de Surface Océanique (IPSO), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Università degli Studi di Roma Tor Vergata [Roma], Interactions Sol Plante Atmosphère (UMR ISPA), Institut National de la Recherche Agronomique (INRA)-Ecole Nationale Supérieure des Sciences Agronomiques de Bordeaux-Aquitaine (Bordeaux Sciences Agro), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Agence Spatiale Européenne = European Space Agency (ESA), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636))

Subjects
[SDU.STU]Sciences of the Universe [physics]/Earth Sciences, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing
Abstract

International audience; The SMOS (Soil Moisture and Ocean Salinity) satellite was successfully launched in November 2009. This ESA led mission for Earth Observation is dedicated to provide soil moisture over continental surface (with an accuracy goal of 0.04 m3/m3) vegetation water content over land and ocean salinity. These geophysical features are important as they control the energy balance between the surface and the atmosphere. Their knowledge at a global scale is of interest for climatic and weather researches in particular in improving models forecasts. The SMOS instrument measures the passive microwave emission of the Earth surface at a frequency of 1,4 GHz (L‐band). The instrument is an interferometer and provides brightness temperatures with an average resolution of 40 km, at several angles and dual polarizations. Data are acquired at two times in a day at 6 am and 18 pm (local time) and insure a complete coverage of the Earth surface in 3 days with a sampling of 15 km. The main products of the mission are of course Soil Moisture and Sea Surface salinity, but also vegetation opacity (directly related to water content) of vegetation covers including forests, surface dielectric constant for level two but also brightness temperatures at the surface, strong winds, root zone soil moisture and RFI (radio frequency interferences) maps. From Level 2 SMOS data several groups have started making new products several of them being either operational or on the verge of being such. We will show some of them or refer to related presentations. They include freeze defreeze (FMI), thin sea ice (Klimat Center Hamburg), near real time brightness temperatures and soon soil moisture (ECMWF), root zone soil moisture and drought indices (USDA and CESBIO). We are also working on more elaborate products such as water fractions, flood risk indexes, improved precipitation with use of assimilated SMOS data, etc. The focus in this presentation will be given to the latter new science products. The purpose of this communication is to present the mission results after almost 6 years in orbit and a major re‐processing as well as some outstanding results already obtained. A special attention will be devoted to level 2 products and to the retrieval quality improvements from version 3 (at launch) to the current version 620.

Published
2015

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