Horizon 1 1 17 ACL : Articles dans des revues avec comité de lecture répertoriées par l'AERES Comptes Rendus Geoscience 32-42 Air temperature Landsat ETM Snow-covered areas Moroccan High-Atlas 2011 fdi:010053381 ENG Comptes Rendus Geoscience 1631-0713 ISI:000288152500004 1 10.1016/j.crte.2010.11.004 https://www.documentation.ird.fr/hor/fdi:010053381 https://www.documentation.ird.fr/intranet/publi/2011/03/010053381.pdf 343 Horizon (IRD) Understanding the spatial distribution of air temperature in mountainous areas is essential in hydrological modelling. In the Moroccan High-Atlas range, the meteorological stations network is sparse. In order to get additional information, we investigated the thermal infrared data supplied by the Enhanced Thematic Mapper (ETM +) sensor onboard the Landsat 7 satellite. The brightness temperature derived from ETM+ images is used as a proxy for air temperature to set up a model that describes its spatial distribution. This model accounts for sun location and topographic characteristics derived from the SRTM digital elevation model. It was evaluated on the Rheraya watershed, a 225-km(2) region located within the semi-arid High-Atlas mountain range, using two different sources of data. The first data set consists in in-situ air temperature collected by meteorological stations installed during the experiment at various altitudes from 1400 to 3200 m. The second data set is satellite estimates of snow-covered areas (SCA) derived from MODIS images over the whole catchment at 500 m spatial resolution. 021 ; 126 UR113 Maroc