Abstract
We here use a coupled atmosphere-surface single column climate model to illustrate how the CFRAM, a new climate feedback analysis framework formulated in Part I of the two-part series papers, can be applied to isolate individual contributions to the total temperature change of a climate system from the external forcing alone, and from each of individual physical and dynamical processes associated with the energy transfer with the space and within the climate system. We demonstrate that the isolation of individual feedbacks in the CFRAM is achieved without referencing to a virtual climate system as in the online feedback suppression method. We show that partial temperature changes estimated by the online feedback suppression method include the “compensating effects” of other feedbacks when the feedback under consideration is suppressed. The partial temperature changes are addable in the CFRAM but they are not in the online feedback suppression method. We also apply the CFRAM to isolate the contributions to the lapse rate feedback from individual physical and dynamical feedback processes. We show that the lapse rate feedback includes not only the partial effect of each feedback that directly contributes to energy flux perturbations at the TOA (such as water vapor feedback), but also the total effects of those feedbacks that do not contribute to energy flux perturbations at the TOA (such as evaporation and moist convection feedbacks). Because the contributions to the lapse rate feedback from various physical and dynamical processes tend to cancel one another, the net lapse rate feedback is a residual of many large terms. This leads to a large uncertainty not only in estimating the lapse rate feedback itself, but also in other feedbacks whose effects are either partially or totally lumped into the lapse rate feedback.



Similar content being viewed by others
Explore related subjects
Discover the latest articles and news from researchers in related subjects, suggested using machine learning.References
Bony S et al (2006) How well do we understand and evaluate climate feedback processes? J Clim 19:3445–3482
Cai M (2005) Dynamical amplification of polar warming. Geophys Res Lett 32:L22710. doi:10.1029/2005GL024481
Cai M (2006) Dynamical greenhouse-plus feedback and polar warming amplification Part I: A dry radiative-transportive climate model. Clim Dyn 26:661–675
Cai M, Lu J-H (2007) Dynamical greenhouse-plus feedback and polar warming amplification Part II: Meridional and vertical asymmetries of the global warming. Clim Dyn 29:375–391
Cess RD (1975) Global climate change: an investigation of atmospheric feedback mechanisms. Tellus 27:193–198
Colman R (2003) A comparison of climate feedbacks in general circulation models. Clim Dyn 20:865–873
Fu Q, Liou KN (1993) Parameterization of the radiative properties of cirrus clouds. J Atmos Sci 50:2008–2025
Hall A, Manabe S (1999) The role of water vapour feedback in unperturbed climate variability and global warming. J Clim 12:2327–2346
Held IM, Soden BJ (2000) Water vapor feedback and global warming. Annu Rev Energy Environ 25:441–475
Lu J-H, Cai M (2008) A new framework for isolating individual feedback processes in coupled general circulation climate models. Part I: Formulation. Clim Dyn. doi:10.1007/s00382-008-0425-3
Manabe S, Wetherald RT (1967) Thermal equilibrium of the atmosphere with a given distribution of relative humidity. J Atmos Sci 24:241–259
Ramaswamy V et al (2001) Radiative forcing of climate change. In: Houghton JT et al (eds) Climate change 2001: the scientific basis. Cambridge University Press, Cambridge, pp 349–416
Schneider EK, Kirtman BP, Lindzen RS (1999) Tropospheric water vapor and climate sensitivity. J Atmos Sci 56:1649–1658
Soden BJ, Held IM (2006) An assessment of climate feedbacks in coupled ocean atmosphere models. J Clim 19:3354–3360
Wetherald R, Manabe S (1988) Cloud feedback processes in a general circulation model. J Atmos Sci 45:1397–1415
Acknowledgments
The authors are indebted to Dr. Qiang Fu who provided us the radiative transfer model (Fu and Liou 1993), which is the core part of the coupled atmosphere-surface single column climate model used in this study. We are grateful for constructive comments from two anonymous reviewers. This work is supported by grants from the NOAA/Office of Global Programs (GC04-163 and GC06-038).
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Cai, M., Lu, J. A new framework for isolating individual feedback processes in coupled general circulation climate models. Part II: Method demonstrations and comparisons. Clim Dyn 32, 887–900 (2009). https://doi.org/10.1007/s00382-008-0424-4
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00382-008-0424-4