Das Projekt "Turbulenzuntersuchungen in der staedtischen Grenzschicht" wird vom Umweltbundesamt gefördert und von Universität Basel, Institut für Meteorologie, Klimatologie und Fernerkundung durchgeführt. The project focusses on micrometeorological measurements of energy exchange and turbulence structure of an urban boundary layer at Basle. An 18-m-tower on the roof of the institute is equipped with the relevant instruments (SONIC anemometer, psychrometers and anemometers...) and reaches up to 32 m above ground level. All measurements are taken over a longer period of several years to cover all meteorological situations. Comparisons with rural conditions are worked out by using data of similar installations of the Regio-Climate-Project REKLIP. Leading Questions: - How is the turbulence structure of a rough urban canopy built up? - What is the influence of the surrounding in terms of building structure, roughness etc.? - How is the turbulent exchange modified during different weather conditions ? - To what extend differ the measurements between urban and rural surfaces?