1. 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

2. IPCC 2001 Clouds: -50 to +35 Wm -2 ABC !

3. See also GCOS papers

4. 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.

6. Stubenrauch (2005) Cloud amount 69/46 Cloud top pressure 588/596 Top minus surface temperature –26/-27 ISCCP vs. TOVS

7. 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.

8. RADIATION PRODUCTS Studies of Earth’s Radiation Climatology began in late 19 th century. -.-.-.-.- At Top of Atmosphere (TOA) with satellite data since ~1960 Now: ERBE, CERES, ScaRaB, GERB (and ISCCP, SRB, others) At Ground with satellite information since ~1975; Now: ISCCP, GEWEX-SRB, + various shorter time series over regions.

9. Radiation product Primarily sensitive to … (in some order of priority) Insolation at TOATSI, Astro-mechanics, spectrum, cut-off angle Planetary albedoClouds, surface albedo, aerosols, scene identification, angular models Outgoing longwave radiation at TOA Temperature of atmosphere and surface, water vapor, clouds, scene, angular models Downward longwave at surfaceAtmospheric temperature and water vapor, clouds Upward longwave at surface Surface skin temperature and effective emittance Downward solar radiation at surfaceClouds, aerosols, moisture; insolation at TOA Upward solar radiation at surfaceDownward solar, surface albedo (and spectrum) Longwave budgets at TOA and surface; integral divergence (Temperatures at surface and in the atmosphere; clouds) Solar budgets at TOA and surface; integral divergence (Clouds, aerosols, surface albedo)

10. 1991 - 1995 Planetary radiation budget 1991 to 1995

11. Validation: Solar (left) and terrestrial (right) at TOA: CERES vs. ISCCP (B.Carlson, GISS)

13. 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

14. AMIP-2: Deviations monthly (1985-88) insolation at TOA from their zonally averages

16. BSRN vs. ISCCP Martin Wild, ETHZ Downward solarDownward atmospheric

17. 1991 - 1995 Total radiative flux divergence 1991 to 1995

19. 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).

20. 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