Quantifying climate feedbacks using radiative kernels

Brian J Soden, Isaac M. Held, Robert C. Colman, Karen M. Shell, Jeffrey T. Kiehl, Christine A. Shields

Research output: Contribution to journalArticle

345 Citations (Scopus)

Abstract

The extent to which the climate will change due to an external forcing depends largely on radiative feedbacks, which act to amplify or damp the surface temperature response. There are a variety of issues that complicate the analysis of radiative feedbacks in global climate models, resulting in some confusion regarding their strengths and distributions. In this paper, the authors present a method for quantifying climate feedbacks based on "radiative kernels" that describe the differential response of the top-of-atmosphere radiative fluxes to incremental changes in the feedback variables. The use of radiative kernels enables one to decompose the feedback into one factor that depends on the radiative transfer algorithm and the unperturbed climate state and a second factor that arises from the climate response of the feedback variables. Such decomposition facilitates an understanding of the spatial characteristics of the feedbacks and the causes of intermodel differences. This technique provides a simple and accurate way to compare feedbacks across different models using a consistent methodology. Cloud feedbacks cannot be evaluated directly from a cloud radiative kernel because of strong nonlinearities, but they can be estimated from the change in cloud forcing and the difference between the full-sky and clear-sky kernels. The authors construct maps to illustrate the regional structure of the feedbacks and compare results obtained using three different model kernels to demonstrate the robustness of the methodology. The results confirm that models typically generate globally averaged cloud feedbacks that are substantially positive or near neutral, unlike the change in cloud forcing itself, which is as often negative as positive.

Original languageEnglish (US)
Pages (from-to)3504-3520
Number of pages17
JournalJournal of Climate
Volume21
Issue number14
DOIs
StatePublished - Jul 15 2008

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climate feedback
top of atmosphere
methodology
climate
clear sky
nonlinearity
radiative transfer
global climate
climate modeling
surface temperature
decomposition
climate change

ASJC Scopus subject areas

  • Atmospheric Science

Cite this

Soden, B. J., Held, I. M., Colman, R. C., Shell, K. M., Kiehl, J. T., & Shields, C. A. (2008). Quantifying climate feedbacks using radiative kernels. Journal of Climate, 21(14), 3504-3520. https://doi.org/10.1175/2007JCLI2110.1

Quantifying climate feedbacks using radiative kernels. / Soden, Brian J; Held, Isaac M.; Colman, Robert C.; Shell, Karen M.; Kiehl, Jeffrey T.; Shields, Christine A.

In: Journal of Climate, Vol. 21, No. 14, 15.07.2008, p. 3504-3520.

Research output: Contribution to journalArticle

Soden, BJ, Held, IM, Colman, RC, Shell, KM, Kiehl, JT & Shields, CA 2008, 'Quantifying climate feedbacks using radiative kernels', Journal of Climate, vol. 21, no. 14, pp. 3504-3520. https://doi.org/10.1175/2007JCLI2110.1
Soden BJ, Held IM, Colman RC, Shell KM, Kiehl JT, Shields CA. Quantifying climate feedbacks using radiative kernels. Journal of Climate. 2008 Jul 15;21(14):3504-3520. https://doi.org/10.1175/2007JCLI2110.1
Soden, Brian J ; Held, Isaac M. ; Colman, Robert C. ; Shell, Karen M. ; Kiehl, Jeffrey T. ; Shields, Christine A. / Quantifying climate feedbacks using radiative kernels. In: Journal of Climate. 2008 ; Vol. 21, No. 14. pp. 3504-3520.
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