MMM SEMINAR NCAR
Ice cloud property profiling using lidars and radars: Ground-based results and outlook for space-based applications
Gerd-Jan van Zadelhoff
Koninklijk Nederlands Meteorologisch Instituut
abstract:
The importance of ice clouds
on the Earth's radiation budget is well recognized. However due to
uncertainties in their properties (e.g. local extinction, particle effective
size [Reff]), they are not well treated in climate and forecasting models.
A comparison of the
microphysical properties of ice clouds, using lidar and radar data, is made for
three sites: Cabauw (the Netherlands), ARM-SGP site (USA), and Chilbolton (UK).
The effective particle size (Reff), extinction and ice water content (IWC) are
derived and correlated to each other, temperature, radar reflectivity, and
depth into the cloud from cloud-top. Within the sensitivity studies performed
it is not possible to construct a single Reff(T,IWC) parameterization valid at
all the three sites and is therefore not applicable in global models. When Reff
is correlated to depth into cloud from cloud-top for different classes of total
cloud thicknesses (H) one can define a single parameterization, using parabolic
descriptions, valid at the three sites and possibly on a global scale.
The last part of the talk
will focus on the derivation of microphysical profiles from space. Next year
CloudSAT and Calipso will be launched, giving for the first time simultaneous
lidar and radar data from space. Simulations of the satellite data, using the
EarthCARE simulator, and their retrievals are presented in preparation of
handling the actual data in 2005.
Refreshments 3:15
NCAR-Foothills Laboratory
3450 Mitchell Lane
Bldg 2 Auditorium (Rm. 1022)