Objectif Various aspects of the measurement and modelling of surface energy fluxes have been studied with particular emphasis on the use of satellite data for the monitoring of fluxes and on their representation in large scale atmospheric models. The main objective was to carry out a small field experiment in the Sahelian region of the Republic of Niger which would contribute to the design of much larger international experiments in semiarid environments. The influence of local minor surface irregularities on the surface energy fluxes and on their measurement was investigated. At the same time measurements of the radiative properties of the different surface types which characterise the area were made to allow the interpretation of satellite data over this region. The experiment showed that even gradients of only a few percent gave rise to significant changes in the local surface energy fluxes and caused problems with some of the techniques commonly used to measure heat fluxes. The measurements of the radiative properties of the different soils showed that in the thermal infrared band the split window techniques should be used with extreme caution. In the visible and near visible bands a large variation in the reflectivity of the soil is found. This is important when using satellite data to estimate amount of vegetation in the conditions of sparse cover typical of the Sahel. The work has cast some new light on the problems of area measurements of the surface energy budget and the results are being incorporated into the design of the large international experiments which will take place in southern Europe and Africa in the next few years. Champ scientifique engineering and technologymechanical engineeringvehicle engineeringaerospace engineeringsatellite technologyengineering and technologyenvironmental engineeringremote sensingsocial sciencespolitical sciencesgovernment systems Programme(s) FP1-STIMULATION 1C - Plan (EEC) to stimulate European scientific and technical cooperation and interchange, 1985-1988 Thème(s) Data not available Appel à propositions Data not available Régime de financement CSC - Cost-sharing contracts Coordinateur UNIVERSITY OF READING Contribution de l’UE Aucune donnée Adresse Whiteknights, Whiteknights House, Palmer Building RG6 6AH READING / SILCHESTER Royaume-Uni Voir sur la carte Coût total Aucune donnée Participants (4) Trier par ordre alphabétique Trier par contribution de l’UE Tout développer Tout réduire FREIE UNIVERSITAET BERLIN Allemagne Contribution de l’UE Aucune donnée Adresse Kaiserswertherstrasse 16-18 BERLIN Voir sur la carte Liens Site web Opens in new window Coût total Aucune donnée NATIONAL RESEARCH COUNCIL OF ITALY Italie Contribution de l’UE Aucune donnée Adresse Via Giovanni Caproni 8 50145 FIRENZE Voir sur la carte Coût total Aucune donnée UNIVERSITAET HANNOVER Allemagne Contribution de l’UE Aucune donnée Adresse Welfengarten 1 B 30167 HANNOVER Voir sur la carte Coût total Aucune donnée UNIVERSITE LOUIS PASTEUR, STRASBOURG 1 France Contribution de l’UE Aucune donnée Adresse Rue Blaise Pascal 4 67070 STRASBOURG Voir sur la carte Coût total Aucune donnée
