Start Submission Become a Reviewer

Reading: Cloud variability, radiative forcing and meridional temperature gradients in a general circu...

Download

A- A+
Alt. Display

Original Research Papers

Cloud variability, radiative forcing and meridional temperature gradients in a general circulation model

Authors:

Peter L. Langen ,

Centre for Ice and Climate, Niels Bohr Institute, University of Copenhagen, Copenhagen, DK
X close

Rodrigo Caballero

Meteorology and Climate Center, University College Dublin, Dublin, IE
X close

Abstract

Due to the non-linearity of cloud—radiation interaction in general circulation models (GCMs), the time-mean cloud radiative forcing (CRF) is in general different from the CRF of time-mean clouds. This implies that a change in temporal cloud variability induces a change in radiative forcing even if there is no change in time-mean cloud properties. Here we investigate this variability contribution to CRF quantitatively in the National Center for Atmospheric Research Community Climate Model 3.6 GCM. In a reference run, the variability contribution is found to account for 35% of the global-mean climatological CRF. The variability contribution peaks in the mid-latitudes and is shown to be driven by synoptic eddy activity. In a climate change experiment, where the atmospheric CO2 is quadrupled, the change in cloud variability offsets 40% of the change in CRF due to the change in mean clouds. It is found that almost all of this effect is due to variability in cloud fraction rather than in cloud water content, and it is traced to the non-linearity introduced by the model’s treatment of vertical cloud overlap. This study indicates the possibility of an eddy variability-climate feedback that has not been extensively studied and quantified in the past.

How to Cite: Langen, P.L. and Caballero, R., 2007. Cloud variability, radiative forcing and meridional temperature gradients in a general circulation model. Tellus A: Dynamic Meteorology and Oceanography, 59(5), pp.641–649. DOI: http://doi.org/10.1111/j.1600-0870.2007.00265.x
  Published on 01 Jan 2007
 Accepted on 25 May 2007            Submitted on 6 Nov 2006

References

  1. Alexeev , V. A. 2003 . Sensitivity to CO2 doubling of an atmospheric GCM coupled to an oceanic mixed layer: a linear analysis . Clim. Dyn . 20 , 775 – 787 .  

  2. Alexeev , V. A. , Langen , P. L. and Bates , J. R. 2005 . Polar amplification of surface warming on an aquaplanet in “ghost forcing” experiments without sea ice feedbacks. Clim. Dyn . https://doi.org/10.1007/s00382-005-0018-3 .  

  3. Barker , H. W. , Stephens , G. L. , Partain , P. T. , Bergman , J. W. , Bonnel , B., and co-authors . 2003. Assessing 1D atmospheric solar radiative transfer models: interpretation and handling of unresolved clouds. J. Climate 16 , 2676-269 9 .  

  4. Barkstrom , B. R. 1984 . The earth radiation budget experiment (ERBE) . Bull. Amer Meteor Soc . 65 , 1170 – 1185 .  

  5. Bergman , J. W. and Salby , M. L. 1997 . The role of cloud diurnal variations in the time-mean energy budget . J. Climate 10 , 1114 – 1124 .  

  6. Bony , S. , Colman , R. , Kattsov , V. M. , Allan , R. P. , Bretherton , C. S., and co-authors . 2006. How well do we understand and evaluate climate change feedback processes? J. Climate 19 , 3445-348 2 .  

  7. Briegleb , B. P. 1992 . Delta-eddington approximation for solar radiation in the NCAR Community Climate Model . J. Geophys. Res . 97 ( D7 ), 7603 – 7612 .  

  8. Caballero , R. and Langen , P. L. 2005 . The dynamic range of poleward energy transport in an atmospheric general circulation model . Geophys. Res. Lett . 32 , L02705 , https://doi.org/10.1029/2004GL021581 .  

  9. Cess , R. D. and Potter , G. L. 1987 . Exploratory studies of cloud radiative forcing with a general circulation model . Tellus 39A , 460 – 473 .  

  10. Cess , R. D. , Genio , A. D. , Dix , M. , Esch , M. , Fowler , L. , and co-authors. 1996 . Cloud feedback in atmospheric general circulation models: an update. J. Geophys. Res . 101D , 12 791 – 12 794 .  

  11. Collins , W. D. 2001 . Parameterization of generalized cloud overlap for radiative calculations in general circulation models. J. Atmos. Sc i . 58 , 3224 – 3242 .  

  12. Colman , R. , Fraser , J. and Rotstayn , L . 2001 . Climate feedbacks in a general circulation model incorporating prognostic clouds. Clim. Dyn . 18 , 103 - 122 .  

  13. Geleyn , J. F. and Hollingsworth , A. 1979 . An economical analytical method for the computation of the interaction between scattering and line absorption of radiation. Contrib. Atmos. Phys . 52 , 1 - 16 .  

  14. Harshvardhan G. and Randall , D. A. 1985 . Comments on “The parame-terization of radiation for numerical weather prediction and climate models”. Mon. Wea. Re v . 113 , 1832 – 1833 .  

  15. Houghton , J. T. , Ding , Y. , Griggs , D. J. , Noguer , M. , van der Linden , P. J. and co-editors. 2001 . IPCC, Climate Change 2001: The Scientific Basis . Cambridge University Press , Cambridge, UK , 944 pp .  

  16. Kiehl , J. T. , Hack , J. J. , Bonan , G. B. , Boville , B. A. , Briegleb , B. P. , and co-authors. 1996 . Description of the NCAR Community Climate Model (CCM3). Technical Report TN-420, CGD, National Center for Atmospheric Research.  

  17. Langen , P. L. 2005 . Polar amplification of surface temperature change in a warming climate . PhD thesis, Niels Bohr Institute , University of Copenhagen , Denmark .  

  18. Langen , P. L. and Alexeev , V. A. 2004 . Multiple equilibria and asymmetric climates in the CCM3 coupled to an oceanic mixed layer with thermodynamic sea ice. Geophys. Res. Lett . 31 , https://doi.org/10.1029/2003GL019039 .  

  19. Lapeyre , G. and Held , I. M. 2004 . The role of moisture in the dynamics and energetics of turbulent baroclinic eddies. J. Atmos. Sc i . 61 , 1693 – 1710 .  

  20. Le Treut , H. , Li , Z. X. and Forichon , M. 1994 . Sensitivity of the LIVID general circulation model to greenhouse forcing associated with two different cloud water parameterizations . J. Climate 7 , 1827 – 1841 .  

  21. Manabe , S. and Strickler , R. F. 1964 . Thermal equilibrium of the atmosphere with a convective adjustment. J. Atmos. Sci . 21 , 361 - 385.  

  22. Oreopoulos , L. and Khairoutdinov , M. 2003 . Overlap properties of clouds generated by a cloud-resolving model. J. Geophys. Res . 108 , https://doi.org/10.1029/2002JD003329 .  

  23. Ramanathan , V. , Cess , R. D. , Harrison , E. F. , Minnis , R , Barlcstrom , B. R. , and co-authors. 1989 . Cloud-radiative forcing and climate: results from the earth radiation budget experiment. Science 243 , 57 - 63 .  

  24. Randall , D. , Khairoutdinov , M. , Aralcawa , A. and Grabowski , W. 2003 . Breaking the cloud parameterization deadlock . Bull. Amer Meteor Soc . 84 , 1547 – 1564 .  

  25. Ringer , M. A. , McAvaney , B. J. , Andronova , N. , Buja , L. E. , Esch , M. , and co-authors. 2006. Global mean cloud feedbacks in idealized climate change experiments. Geophys. Res. Lett . 33 , L07718 , https://doi.org/10.1029/2005GL025370 .  

  26. Rossow , W. B. and Schiffer , R. A. 1991 . ISCCP cloud data products . Bull. Am. Met. Soc . 72 , 2 – 20 .  

  27. Schneider , E. K. , Kirtman , B. P. and Lindzen , R. S. 1999 . Tropospheric water vapor and climate sensitivity. J. Atmos. Sc i . 56 , 1649 – 1658 .  

  28. Sloan , L. C. and Pollard , D. 1998 . Polar stratospheric clouds: A high latitude warming mechanism in an ancient greenhouse world . Geophys. Res. Lett . 25 , 3517 – 3520 .  

  29. Soden , B. J. , Broccoli , A. J. and Hemler , R. S. 2004 . On the use of cloud forcing to estimate cloud feedback . J. Climate 17 , 3661 – 3665 .  

  30. Soden , B. J. and Held , I. M. 2006 . An assessment of climate feedbacks in coupled ocean atmosphere models . J. Climate 19 , 3354 – 3360 .  

  31. Stephens , G. L. 2005 . Cloud feedbacks in the climate system: a critical review . J. Climate 18 , 237 – 273 .  

  32. Stephens , G. L. , Wood , N. B. and Gabriel , P. M. 2004 . An assessment of the parameterization of subgrid-scale cloud effects on radiative transfer. Part I: vertical overlap. J. Atmos. Sc i . 61 , 715 – 732 .  

  33. Taylor , K. E. and Ghan , S. J. 1992 . An analysis of cloud liquid water feedback and global climate sensitivity in a general circulation model . J. Climate 5 , 907 – 919 .  

  34. Vavrus , S. J. 2004 . The impact of cloud feedbacks on arctic climate under greenhouse forcing . J. Climate 17 , 603 – 615 .  

  35. Wetherald , R. T. and Manabe , S. 1988 . Cloud feedback processes in a general circulation model. J. Atmos. Sc i . 45 , 1397 – 1415 .  

  36. Yin , J. H. 2005 . A consistent poleward shift of the storm tracks in simulations of 21st century climate . Geophys. Res. Lett . 32 , L18701 .  

  37. Webb , M. J. , Senior , C. A. , Sexton , D. M. H., Ingram , W.J. , Williams , K. D. , and co-authors . 2006. On the contribution of local feedback mechanisms to the range of climate sensitivity in two GCM ensembles. Clim. Dyn . 27 , 17 - 38 .  

  38. Zhang , M. H. , Hack , J. J. , Kiehl , J. T. and Cess , R. D. 1994 . Diagnostic study of climate feedback processes in atmospheric general circulation models . J. Geophys. Res . 99 ( 18 ), 5525-5538 .  

comments powered by Disqus