B. M. Ba, R. Frouin, E. S. Nicholson, and G. Dedieu, Satellite-Derived Surface Radiation Budget over the African Continent. Part I: Estimation of Downward Solar Irradiance and Albedo, Journal of Climate, vol.14, issue.1, pp.45-58, 2001.
DOI : 10.1175/1520-0442(2001)014<0045:SDSRBO>2.0.CO;2

L. A. Bastidas, H. V. Gupta, S. Sorooshian, W. J. Shuttleworth, and Z. L. Yang, Sensitivity analysis of a land surface scheme using multicriteria methods, Journal of Geophysical Research: Atmospheres, vol.7, issue.11, pp.19481-19490, 1999.
DOI : 10.1029/1999JD900155

G. Boulet, J. D. Kalma, Y. H. Kerr, and A. Chehbouni, Deriving catchment-scale water and energy balance parameters using data assimilation based on extended Kalman filtering, Hydrological Sciences Journal, vol.75, issue.3, pp.47-449, 2002.
DOI : 10.1029/1999WR900258

K. L. Brubaker, D. Entekhabi, and P. S. Eagleson, Estimation of Continental Precipitation Recycling, Journal of Climate, vol.6, issue.6, pp.1077-1089, 1993.
DOI : 10.1175/1520-0442(1993)006<1077:EOCPR>2.0.CO;2

P. J. Camillo and R. J. Gurney, A RESISTANCE PARAMETER FOR BARE-SOIL EVAPORATION MODELS, Soil Science, vol.141, issue.2, pp.95-105, 1986.
DOI : 10.1097/00010694-198602000-00001

P. Cayrol, L. Kergoat, S. Moulin, G. Dedieu, and A. Chehbouni, Calibrating a Coupled SVAT???Vegetation Growth Model with Remotely Sensed Reflectance and Surface Temperature???A Case Study for the HAPEX-Sahel Grassland Sites, Journal of Applied Meteorology, vol.39, issue.12, pp.2452-2472, 2000.
DOI : 10.1175/1520-0450(2000)039<2452:CACSVG>2.0.CO;2

W. T. Crow and E. F. Wood, The assimilation of remotely sensed soil brightness temperature imagery into a land surface model using Ensemble Kalman filtering: a case study based on ESTAR measurements during SGP97, Advances in Water Resources, vol.26, issue.2, pp.137-149, 2003.
DOI : 10.1016/S0309-1708(02)00088-X

A. D. Culf, S. J. Allen, J. H. Gash, C. R. Lloyd, and J. S. Wallace, Energy and water budgets of an area of patterned woodland in the Sahel Agricultural and Forest Meteorology, pp.65-80, 1993.

R. Delécolle, S. J. Maas, M. Guérif, and F. Baret, Remote sensing and crop production models: present trends, ISPRS Journal of Photogrammetry and Remote Sensing, vol.47, issue.2-3, pp.145-161, 1992.
DOI : 10.1016/0924-2716(92)90030-D

R. E. Dickinson, Land processes in climate models, Remote Sensing of Environment, vol.51, issue.1, pp.27-38, 1995.
DOI : 10.1016/0034-4257(94)00062-R

G. Evensen, D. Dee, and J. Schroter, Parameter estimation in dynamical models, NATO ASI, Ocean Modelling and Parameterizations, 1998.

H. Fang, S. Liang, and A. Kuusk, Retrieving leaf area index using a genetic algorithm with a canopy radiative transfer model, Remote Sensing of Environment, vol.85, issue.3, pp.257-270, 2003.
DOI : 10.1016/S0034-4257(03)00005-1

P. L. Frison and E. Mougin, Monitoring global vegetation dynamics with ERS-1 wind scatterometer data, International Journal of Remote Sensing, vol.6, issue.16, pp.3201-3218, 1996.
DOI : 10.1080/01431169608949139

P. L. Frison and E. Mougin, Use of ERS-1 wind scatterometer data over land surfaces, IEEE Transactions on Geoscience and Remote Sensing, vol.34, issue.2, pp.1-11, 1996.
DOI : 10.1109/36.485131

P. L. Frison, E. Mougin, and P. Hiernaux, Observations and interpretation of seasonal ERS-1 wind scatterometer data over northern Sahel (Mali) Remote Sensing of Environment, pp.233-242, 1998.

J. H. Gash, J. S. Wallace, C. R. Lloyd, A. J. Dolman, M. V. Sivakumar et al., Measurements of evaporation from fallow Sahelian savannah at the start of the dry season, Quarterly Journal of the Royal Meteorological Society, vol.7, issue.500, pp.749-760, 1991.
DOI : 10.1002/qj.49711750005

H. Guerin, D. Friot, N. Mbaye, and D. Richard, Alimentation des ruminants Domestiques sur pâturages Naturels Sahéliens et Sahelosoudanien, Etude Méthologique dans la région du Ferlo au Sénégal, Institut d'Elevage et de Medecine vétérinaire des Pays Tropicaux (I.E.M.V.T.), p.pp, 1991.

M. T. Hallikainen, F. T. Ulaby, M. C. Dobson, M. A. El-rayes, and L. Wu, Microwave Dielectric Behavior of Wet Soil-Part 1: Empirical Models and Experimental Observations, IEEE Transactions on Geoscience and Remote Sensing, vol.23, issue.1, pp.25-34, 1985.
DOI : 10.1109/TGRS.1985.289497

P. H. Hiernaux and C. O. Justice, Suivi du développement végétal au cours de l'e ´té 1984 dans le Sahel Malien, International Journal of Remote Sensing, vol.11, pp.1515-1531, 1986.

L. Jarlan, P. Mazzega, and E. Mougin, Retrieval of land surface parameters in the Sahel from ERS wind scatterometer data: a "brute force" method, IEEE Transactions on Geoscience and Remote Sensing, vol.40, issue.9, pp.2056-2062, 2002.
DOI : 10.1109/TGRS.2002.802500

L. Jarlan, E. Mougin, P. L. Frison, P. Mazzega, and P. Hiernaux, Analysis of ERS wind scatterometer time series over Sahel (Mali), Remote Sensing of Environment, vol.81, issue.2-3, 2002.
DOI : 10.1016/S0034-4257(02)00015-9

L. Jarlan, P. Mazzega, E. Mougin, M. Schoenauer, F. Lavenu et al., Mapping of Sahelian vegetation parameters from ERS scatterometer data with an evolution strategie algorithm, pp.72-84, 2003.

P. Kabat, A. J. Dolman, and J. A. Elbers, Evaporation, sensible heat and canopy conductance of fallow savannah and patterned woodland in the Sahel, Journal of Hydrology, vol.188, issue.189, pp.494-515, 1997.
DOI : 10.1016/S0022-1694(96)03190-3

P. Kabat, R. W. Hutjes, and R. A. Feddes, The scaling characteristics of soil parameters: From plot scale heterogeneity to subgrid parameterization, Journal of Hydrology, vol.190, issue.3-4, pp.363-396, 1997.
DOI : 10.1016/S0022-1694(96)03134-4

L. Houérou and H. N. , The grazing land ecosystems of the African Sahel, Ecological Studies, vol.75, 1989.

C. R. Lloyd, P. Bessemoulin, F. Cropley, A. D. Culf, A. J. Dolman et al., An intercomparison of surface flux measurements during HAPEX-Sahel, Journal of Hydrology, pp.188-189, 1997.

D. Lo-seen, E. Mougin, S. Rambal, A. Gaston, and P. Hiernaux, A regional Sahelian grassland model to be coupled with multispectral satellite data. II: Toward the control of its simulations by remotely sensed indices, Remote Sensing of Environment, vol.52, issue.3, pp.194-206, 1995.
DOI : 10.1016/0034-4257(94)00127-9

S. J. Maas, Using Satellite Data to Improve Model Estimates of Crop Yield, Agronomy Journal, vol.80, issue.4, pp.655-662, 1988.
DOI : 10.2134/agronj1988.00021962008000040021x

L. Mahrt, Surface heterogeneity and vertical structure of the boundary layer. Boundary-Layer Meteorology, pp.33-62, 2000.

R. D. Magagi and Y. H. Kerr, Characterization of surface parameters over arid and semi???arid areas by use of ERS???1 Windscatterometer, Remote Sensing Reviews, vol.3, issue.3, pp.133-155, 1997.
DOI : 10.1080/02757259709532335

Z. Michalewicz, Genetic Algorithms+Data Structure=Evolution Programs, 1996.
DOI : 10.1007/978-3-662-02830-8

J. L. Monteith, Evaporation and environment. State and Movement of Water in Living Organisms (19th Symposium of the Society for, Experimental Biology), pp.205-234, 1965.

R. Morel, P. Cilss, and . Niamey, Atlas agroclimatique des pays de la zone du CILSS, Programme Agrhymet, vol.11, 1992.

E. Mougin, D. Lo-seen, S. Rambal, A. Gaston, and P. Hiernaux, A regional Sahelian grassland model to be coupled with multispectral satellite data. I: Model description and validation, Remote Sensing of Environment, vol.52, issue.3, pp.181-193, 1995.
DOI : 10.1016/0034-4257(94)00126-8

S. E. Nicholson, Land surface processes and Sahel climate, Reviews of Geophysics, vol.3, issue.189, pp.117-139, 2000.
DOI : 10.1029/1999RG900014

Y. Oh, K. Sarabandi, and F. T. Ulaby, An empirical model and an inversion technique for radar scattering from bare soil surfaces, IEEE Transactions on Geoscience and Remote Sensing, vol.30, issue.2, pp.370-381, 1992.
DOI : 10.1109/36.134086

J. Polcher, K. Laval, L. Dqmenil, J. Lean, and P. R. Rowntree, Comparing three land surface schemes used in general circulation models, Journal of Hydrology, vol.180, issue.1-4, pp.373-394, 1995.
DOI : 10.1016/0022-1694(95)02886-2

I. Rechenberg, Evolution strategie: Optimierung Technisher Systeme nach Prinzipien des Biologischen Evolution, 1973.

R. Reichle, D. B. Mc-laughlin, and D. Entekhabi, Variational data assimilation of microwave radiobrightness observations for land surface hydrologic applications, IEEE Transactions on Geoscience and Remote Sensing, issue.8, pp.39-1708, 2001.

R. Reichle, B. D. Mc-laughlin, and D. Entekhabi, Hydrologic Data Assimilation with the Ensemble Kalman Filter, Monthly Weather Review, vol.130, issue.1, pp.103-114, 2002.
DOI : 10.1175/1520-0493(2002)130<0103:HDAWTE>2.0.CO;2

. Schoenauer, EvolC User Manual Evolution computation, Control and Cybernetics, vol.26, issue.3, pp.307-338, 1995.

H. P. Schwefel, Numerical optimization of computer models, 1981.

P. J. Sellers, M. D. Heiser, F. G. Hall, S. B. Verma, R. L. Desjardins et al., The impact of using area-averaged land surface properties ???topography, vegetation condition, soil wetness???in calculations of intermediate scale (approximately 10 km2) surface-atmosphere heat and moisture fluxes, Journal of Hydrology, vol.190, issue.3-4, pp.269-301, 1997.
DOI : 10.1016/S0022-1694(96)03130-7

J. Shukla and Y. Mintz, Influence of Land-Surface Evapotranspiration on the Earth's Climate, Science, vol.215, issue.4539, pp.1498-1500, 1982.
DOI : 10.1126/science.215.4539.1498

M. V. Sivakumar, Exploiting rainy season potential from the onset of rains in the Sahelian zone of West Africa, Agricultural and Forest Meteorology, vol.51, issue.3-4, pp.321-332, 1990.
DOI : 10.1016/0168-1923(90)90116-N

C. M. Taylor and T. Lebel, Observational Evidence of Persistent Convective-Scale Rainfall Patterns, Monthly Weather Review, vol.126, issue.6, pp.1597-1607, 1998.
DOI : 10.1175/1520-0493(1998)126<1597:OEOPCS>2.0.CO;2

Y. Tracol, E. Mougin, and P. Hiernaux, Testing a Sahelian grassland model against herbaceous mass measurements, Ecological Modelling, 2004.

F. T. Ulaby and M. A. El-rayes, Microwave Dielectric Spectrum of Vegetation - Part II: Dual-Dispersion Model, IEEE Transactions on Geoscience and Remote Sensing, vol.25, issue.5, pp.550-557, 1987.
DOI : 10.1109/TGRS.1987.289833

W. Wagner and K. Scipal, Large-scale soil moisture mapping in western Africa using the ERS scatterometer, IEEE Transactions on Geoscience and Remote Sensing, vol.38, issue.4, pp.1777-1782, 2000.
DOI : 10.1109/36.851761

J. S. Wallace and C. J. Holwill, Soil evaporation from tiger-bush in south-west Niger, Journal of Hydrology, vol.188, issue.189, pp.188-189, 1997.
DOI : 10.1016/S0022-1694(96)03185-X

J. S. Wallace, C. R. Lloyd, and M. V. Sivakumar, Measurements of soil, plant and total evaporation from millet over Niger Agricultural and Forest Meteorology, pp.149-169, 1993.

J. S. Wallace, J. M. Roberts, and M. V. Sivakumar, The estimation of transpiration from sparse dryland millet using stomatal conductance and vegetation area indices Agricultural and Forest Meteorology, pp.35-49, 1990.

Q. J. Wang, Using genetic algorithms to optimise model parameters. Environmental Modelling and Software, pp.27-34, 1997.

I. H. Woodhouse and D. H. Hoekman, Determining land-surface parameters from the ERS wind scatterometer, IEEE Transactions on Geoscience and Remote Sensing, vol.38, issue.1, pp.126-140, 2000.
DOI : 10.1109/36.823907