Introduction to the EUCREX-94 mission 206

Part of the EUCREX-94 experiment was devoted to the study of the radiative properties of boundary layer clouds in relation with their microphysical an d structural properties. Mission 206, on April 18, is particularly attracti ve because of a general trend in cloud geometrical thickness within the sam pled region, with corresponding values of optical thickness between 4 and 7 0. The cloud system has been extensively documented in situ with an instrum ented aircraft, while two other aircraft were measuring its radiative prope rties with radiometers and a lidar. This paper introduces the scientific ob jectives of the experiment and describes the instrumental setup. After a pr esentation of the meteorological situation, the various papers of this seri es are briefly introduced. (C) 2000 Elsevier Science B.V. All rights reserv ed.