Abstract : The UBL/CLU experiment is a side project of the regional photochemistry experiment ESCOMPTE over the Berre-Marseille area. It took advantage of the large experimental set-up, with chemistry and dynamics, ground-based and airborne instrumentations, including a large array of vertical and 3D sounders. With additional specific instrumentation in the lower urban atmosphere, the UBL/CLU project aimed at documenting the dynamics and thermodynamics of the urban boundary layer (UBL) of the Marseille area during sunny periods. To date the initial data analyses include (a) the quality control inter-comparison of energy flux instrumentations, (b) the quality evaluation of the measurements at the urban stations, (c) the comparison of the Town Energy Balance model with the data obtained over the city center, (d) the evaluation of heat flux measurements with the scintillometers, (e) the temperature and moisture variability at the canopy level, (f) the 3D structure of the UBL during sea breeze episodes, (g) the visible and thermal infrared signatures of the urban canopy, (h) the numerical urban data base and satellite data analysis to generate high resolution land use and aerodynamic roughness maps.
