An assessment of data products for studies of clouds and radiation (INVITED) Ehrhard Raschke University of Hamburg, Germany William R. Rossow, Yuan-Chong Zhang NASA, GISS & Columbia University, New York NY Paul W. Stackhouse NASA, LaRC Hampton VA (With contributions by B. Carlson, M. Giorgetta, S. Kinne, M. Wild, R. Cess, G. Potter) 5 th GEWEX Science Conference, 20 – 24 June 2005 Orange County, California
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An assessment of data products for studies of clouds and radiation (INVITED) Ehrhard Raschke University of Hamburg, Germany William R. Rossow, Yuan-Chong.
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An assessment of data products for studies of clouds and radiation
(INVITED)
Ehrhard RaschkeUniversity of Hamburg, Germany
William R. Rossow, Yuan-Chong ZhangNASA, GISS & Columbia University, New York NY
Paul W. StackhouseNASA, LaRC Hampton VA
(With contributions by B. Carlson, M. Giorgetta, S. Kinne, M. Wild, R. Cess, G. Potter)
5th GEWEX Science Conference, 20 – 24 June 2005
Orange County, California
IPCC 2001
Clouds: -50 to +35 Wm-2
ABC !
See also GCOS papers
CLOUDS
Surface Observations,
RAWIN-Sondes,
(Neph-Analyses, photographic averages)
TOVS, ISCCP, HIRS/2, SAGE, POLDER, and many others
To contrast clouds against background of passive measurements: Correlative data sets on state of atmosphere and ground are needed.
Stubenrauch (2005)
Cloud amount 69/46
Cloud top pressure 588/596
Top minus surface temperature –26/-27
ISCCP vs. TOVS
Summary for clouds:
1. There are now several data sets available for geometric and radiometric cloud field properties and for occurrence of clouds covering more than 15 years with largest uncertainties over Polar Regions.
2. There are further numerous results available for microphysical cloud field properties covering shorter periods.
CONCLUSIONS:
1. The cloud products are not necessarily compatible due to different techniques of measurements and analyses and sampling.
2. GEWEX must develop and accept an appropriate terminology on cloud characteristics.
3. Significant improvements expected when “A-Train data” is included.
RADIATION PRODUCTS
Studies of Earth’s Radiation Climatology began in late 19th century.
-.-.-.-.-
At Top of Atmosphere (TOA) with satellite data since ~1960
AMIP-2, mean incoming solar radiation at TOA in May and November (1985-1988)(with R. Cess, S. Kinne, M. Giorgetta, M. Wild)
DJF
TSI PMOD-composite 2005
AMIP-2: Deviations monthly (1985-88) insolation at TOA from their zonally averages
BSRN vs. ISCCPMartin Wild, ETHZ
Downward solar Downward atmospheric
1991 - 1995
Total radiative flux divergence
1991 to 1995
Summary for Radiation Products(from models, satellite data and computations with climate data)
1. At TOA: ALL (!!) radiation climatologies must use “same solar forcing”. Upward fluxes and CE-s need thorough validation vs. CERES and other space-based measurements.
2. At surface: Atmospheric transmittance and emittance: ISCCP > SRB; surface albedo and emission seasonally different; cloud effects: need comparison between measured and computed ! Use network data !
3. Radiative flux divergence: Uncertainties are dominated by errors in the net budgets at both boundaries.
-.-.-.-.-
There is an urgent need to establish and accept scale dependent uncertainty and stability criteria for cloud and radiation products and data sets must be characterized accordingly. The next workshop should develop mechanisms for a steady quality control (also for correlative data).
Thanks to all contributors to
the data sets
E.R. enjoyed excellent hospitability in Sapporo, and at CCSR and at NIPR in Tokyo.
GEWEX: develop and apply quality control procedures