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Satellite-based datasets for validation of regional climate models:
The CM-SAF product suite and new possibilities for processing with
'climate data operators'
F. Kaspar (1), J. Schulz (1), P. Fuchs (1), R. Hollmann (1), M. Schröder (1), R. Müller (1), K.-G.
Karlsson (2), R. Roebeling (3), A. Riihelä (4), B. de Paepe (5), R. Stöckli (6) and U. Schulzweida (7)
(1) Satellite Application Facility on Climate Monitoring (CM-SAF), Deutscher Wetterdienst, Offenbach, Germany
(frank.kaspar@dwd.de), (2) CM-SAF, Swedish Meteorological and Hydrological Institute, (3) CM-SAF, Royal Netherlands
Meteorological Institute, (4) CM-SAF, Finnish Meteorological Institute, (5) CM-SAF, Royal Meteorological Institute of
Belgium, (6) CM-SAF, MeteoSwiss, (7) Max-Planck-Institute for Meteorology, Hamburg, Germany
1. Introduction: EUMETSAT’s Satellite
Application Facility on Climate Monitoring
(CM-SAF)
Increasing the confidence in model-based climate
projections requires evaluation of climate simulations with
high-quality observational datasets. Satellite data provide
information on the climate system that are not available or
difficult to measure from the Earth‘s surface like top of
atmosphere radiation, cloud properties or humidity in the
upper atmosphere. In particular over ocean and sparsely
populated areas space-based observations are largely the
only data source. Especially for evaluating the generality of
climate models across varying locations, satellite-derived
datasets have the strong advantage of consistent
measurements and processing methodologies across regions.
Existing satellite time series, especially from operational
meteorological satellites, now reach a length that makes
them useful for climate analysis.
sufficient to perform studies of inter-annual variability and
possibly trends.
2. The CM-SAF product suite
The following products are currently available and can be
ordered free-of-charge at www.cmsaf.eu:
Cloud parameters: Cloud fractional cover (CFC), cloud
type (CTY), cloud top pressure, height and temperature
(CTP/CTH/CTT), cloud phase (CPH), cloud optical
thickness (COT), cloud water path (CWP).
These products are available at a spatial resolution of
(15km) 2 . For the CM-SAF Baseline Area (30°N to 80°N,
60°W to 60°E, i.e. Europe and the North Atlantic) they are
derived from the AVHRR sensor and are available since
01.01.2004. For the Meteosat Disc Area (see Figure 1)
they are derived from the SEVIRI sensor and are available
since 01.09.2005.
Following this idea, EUMETSAT‘s Satellite Application
Facility on Climate Monitoring (CM-SAF) is dedicated to
the high-quality long-term monitoring of the climate
system‘s state and variability. CM-SAF supports the
analysis and diagnosis of climate parameters in order to
detect and understand changes in the climate system. One
goal is to support the climate modelling communities by the
provision of satellite-derived geophysical parameter data
sets.
CM-SAF provides data sets of several cloud parameters,
surface albedo, radiation fluxes at top of the atmosphere and
at the surface, atmospheric temperature and water vapour
profiles as well as vertically integrated water vapour (total,
layered integrated). They are derived from geostationary
(SEVIRI and GERB instruments) and polar-orbiting
(AVHRR, ATOVS and SSM/I instruments) meteorological
satellites (Schulz et al., 2008).
Products from the SEVIRI instrument on-board the
geostationary Meteosat Second Generation satellites cover
the full visible Earth disk, that extends from South America
to the Middle East, with Africa fully included and Europe in
the North. Products derived from the AVHRR-sensor onboard
the polar-orbiting satellites cover Europe, the East
Atlantic and the Inner Arctic. For these sensors, cloud and
radiation products are generated at original pixel resolution
of a few kilometres. These intermediate products are then
aggregated to daily and monthly averages in equal-area
projections. SSM/I (over ocean only) and ATOVS water
vapour products offer global coverage. The SSM/I total
column water vapour series based on intercalibrated
radiances already covers almost 20 years with a quality
Surface radiation budget / Wm -2
-100 -20 60 140 220 300
Figure 1. Monthly mean surface radiation budget
for September 2007 [W/m 2 ] derived from Meteosat-
9 / SEVIRI observations (geostationary satellite)
Humidity products: Total (HTW) and layered (HLW)
precipitable water. Mean temperature and relative
humidity for 5 layers as well as specific humidity and
temperature at the six layer boundaries (HSH).
Spatial resolution is (90km) 2 . The products are derived
from the ATOVS sensor, have global coverage and are
available from 01.01.2004 onwards.
Surface radiation: Incoming short-wave radiation (SIS)
surface albedo (SAL), net shortwave radiation (SNS)
net longwave radiation (SNL), downward long-wave
radiation (SDL), outgoing long-wave radiation (SOL),
surface radiation budget (SRB)
Spatial resolution is (15km) 2 . For the CM-SAF Baseline
Area they are derived from AVHRR and are available