English Abstract To understand and model the radiative transport in a
cloudy atmosphere, information on the cloud structure, optical properties
and microphysics is indispensable. In order to obtain a detailed data set,
four national institutes joined their efforts in the CLARA project. In the
cause of the project the total number of participating institutes increased
to ten. In total three experimental campaigns took place in the Netherlands
in 1996. An extensive set of instrumentation was employed, including
lidars, radar, infrared radiometers, microwave radiometer and radiosondes.
Furthermore, in-situ aircraft measurements were carried out to measure the
cloud droplet size distribution and the liquid water content. The data set
is now available on CD-ROM. A platform independent JAVA interface allows
the visualisation of most of the high resolution data. Extensive analysis
of the observations has taken place. Research topics are:- Validation of
satellite retrieval algorithms, - Lidar observations of cloud (optical)
parameters, - Micro-physical properties of Sc clouds to estimate the
indirect aerosol effect, - Cloud radar research, - Development and
validation of sensor synergy algorithms, - Evaluation of cloud
parameterizations in atmospheric models. An overview of the research
performed within the CLARA project is presented in this final report. Much
of the research will continue for the next few years. An important benefit
of CLARA is that it was successful in organising a good scientific
co-operation between the different research groups. In this way a national
cloud remote sensing community was developed. This community is still
growing.
