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European Cloud and Radiation Experiment : modelling, measurementsand observations of physical processes in cirrus clouds

Objective

To describe and model how cloud fields, in particular the high
ice clouds, influence the radiative energy transfer in the
climate system and influence processes determining the climate
and to assess the results of the International Cloud Climatology
Project.


High ice clouds, cirrus, tend to enhance the greenhouse effect of
the atmosphere while lower cloud fields tend to decrease it and
thus contribute to the cooling of the system. The work is aiming
to improve respective algorithms in climate and global/regional
circulation models.

Extensive airborne and ground-based measurements are performed of
microphysical and radiative cloud field properties, and of the
dynamical and thermodynamical structure of the ambient
atmosphere, where high-resolution satellite imagery provides
additional information on the horizontal cloud structure.
Campaigns have been made so far over Germany, Scotland and
adjacent sea areas, and near Spitsbergen, biggy-packing with
other experiments. The work has been concentrating primarily on
the high-level ice clouds (cirrus) and lower mostly broken cloud
fields.

These data are analyzed with respect to their relations to
larger-scale atmospheric field properties. The case studies will
be supported by investigations of detailed processes and their
contributions to the observed quantities with cloud resolving
numerical models. There are two kinds of models in use:
one-dimensional simulating the microphysical properties and the
cloud life cycles in response to external forcings (radiation,
large scale lifting), and three-dimensional dynamical models to
reconstruct observed episodes and estimate future developments.
Presently, the model simulations are done without consideration
of external atmospheric dynamics (no nesting of cloud models into
larger scale models). The spatial resolution ranges from about
100 m to 10 km.

Data from Meteosat and the NOAA satellites are analyzed with
respect to their information contents on cloud properties (ice
and water content, particle sizes, radiative transfer properties,
and their horizontal structures) for comparison with the field
measurements and with the results of the operational ISCCP.
Detailed numerical and laboratory studies of scattering and
absorption properties of non-spherical cloud particles have been
done to improve cloud retrieval algorithms.

Funding Scheme

CSC - Cost-sharing contracts

Coordinator

GKSS - FORSCHUNGSZENTRUM GEESTHACHT GMBH
Address
Max-planck-strasse 1
Geesthacht
Germany

Participants (7)

CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE
France
Address
Ecole Polytechnique
91128 Palaiseau
GERMAN AEROSPACE CENTRE
Germany
Address
Linder Höhe
51147 Koeln
SECRETARY OF STATE FOR DEFENCE - MINISTRY OF DEFENCE
United Kingdom
Address
D.e.r.a. Aerospace, Building Y 46
GU14 0LX Farnborough
STOCKHOLM UNIVERSITET
Sweden
Address
12,Svante Arrheniusväg 12, Arrhenius Laboratory
106 91 Stockholm
UNIVERSITÉ BLAISE PASCAL CLERMONT-FERRAND II
France
Address
Avenue Des Landais 24
63177 Aubière
University of Manchester Institute of Science and Technology
United Kingdom
Address
Sackville Street
M60 1QD Manchester
Université de Lille I (Université des Sciences et Technologies de Lille Flandres Artois)
France
Address
Domaine Universitaire Scientifique
59655 Villeneuve D'ascq