R. Hollmann 1 , C. Poulsen 2 , U. Willen 3 , C. Stubenrauch 4 , M. Stengel 1 , and the Cloud CCI consortium 1 Deutscher Wetterdienst, 2 RAL Space, 3 SMHI, 4 LMD. Cloud_cci: From Phase 1 to Phase 2. Cloud_cci: Achievements phase 1.
R. Hollmann1, C. Poulsen2, U. Willen3, C. Stubenrauch4, M. Stengel1, and the Cloud CCI consortium
1Deutscher Wetterdienst, 2 RAL Space, 3SMHI, 4LMD
Cloud_cci: From Phase 1 to Phase 2
Benefit for user community – Added value of ESA Cloud CCI products:
Spectral consistency of derived parameters, which is achievedby an optimal-estimation approach based on fitting a physically consistent cloud model to satellite observations simultaneously from the visible to the mid-infrared.
Uncertainty characterization, which has been inferred by the application of the optimal estimation approach as physically consistent single pixel uncertainty estimation and further propagated to the final product.
Increased temporal resolution by including multiple polar-orbiting satellite instruments, which also allows for mature cloud property histograms on 0.5° resolution due to high increased sampling rate.
Comprehensive assessment and documentation of the retrieval schemes and the derived cloud property datasets including the exploitation of applicability for evaluation of climate models and reanalyses.
Global Climate Observing System Target Requirements:
Cloud Essential Climate Variables(2011 update)
assuming cloud feedback similar to rad forcing of 0.3Wm-2 (~ 20% of current GHG forcing)
radiative forcing depends on CAE (and not CA)
=> target ranges (opt thick/ low clouds - opt thin Ci (CEM=0.2) )
based on NISTIR 7047 report (March 2004)
Achieved uncertainties & accuracies ?
Comparison with station data: AVHRR, June 2008
Comparison for Histograms
Comparison for Liquid water path: AVHRR, June 2008
L3 COD-CP histograms to determine cloud radiative effects
or radiative flux kernels of(Zelinka et al. 2012)
2) weight fluxes by COD-CP histograms(monthly 1° x 1° map resolution)
differences in COD-CP distributions lead to differences in radiative effects
(transformation of IR emissivity to COD -> COD < 10 => underestimation of SW effect)