Cloud albedo feedback and the super greenhouse effect in a global coupled GCM (original) (raw)
Abstract
Two competing cloud-radiative feedbacks identified in previous studies i.e., cloud albedo feedback and the super greenhouse effect, are examined in a sensitivity study with a global coupled ocean-atmosphere general circulation model. Cloud albedo feedback is strengthened in a sensitivity experiment by lowering the sea-surface temperature (SST) threshold in the specified cloud albedo feedback scheme. This simple parameterization requires coincident warm SSTs and deep convection for upper-level cloud albedos to increase. The enhanced cloud albedo feedback in the sensitivity experiment results in decreased maximum values of SST and cooler surface temperatures over most areas of the planet. There is also a cooling of the tropical troposphere with attendant global changes of atmospheric circulation reminiscent of those observed during La Niña or cold events in the Southern Oscillation. The strengthening of the cloud albedo feedback only occurs over warm tropical oceans (e.g., the western Pacific warm pool), where there is increased albedo, decreased absorbed solar radiation at the surface, stronger surface westerlies, enhanced westward currents, lower temperatures, and decreased precipitation and evaporation. However, the weakened convection over the tropical western Pacific Ocean alters the large-scale circulation in the tropics such that there is increased upper-level divergence over tropical land areas and the tropical Indian Ocean. This results in increased precipitation in those regions and intensified monsoonal regimes. The enhanced precipitation over tropical land areas produces increased clouds and albedo and wetter and cooler land surfaces. These additional contributions to decreased absorbed solar input at the surface combine with similar changes over the tropical oceans to produce the global cooling associated with the stronger cloud albedo feedback. Increased low-level moisture convergence and precipitation over the tropical Indian Ocean enhance slightly the super greenhouse effect there. But the stronger cloud albedo feedback is still the dominant effect, although cooling of SSTs in that region is less than in the tropical western Pacific Ocean. The sensitivity experiment demonstrates how a regional change of radiative forcing is quickly transmitted globally through a combination of radiative and dynamical processes in the coupled model. This study points to the uncertainties involved with the parameterization of cloud albedo and the major implications of such parameterizations concerning the maximum values of SST, global climate sensitivity, and climate change.
Access this article
Subscribe and save
- Starting from 10 chapters or articles per month
- Access and download chapters and articles from more than 300k books and 2,500 journals
- Cancel anytime View plans
Buy Now
Price excludes VAT (USA)
Tax calculation will be finalised during checkout.
Instant access to the full article PDF.
Similar content being viewed by others
References
- Boer GJ (1993) Climate change and the regulation of the surface moisture and energy budgets. Clim Dyn 8:225–239
Google Scholar - Collins WD, Valero FPJ, Pilewskie P (1995) The relation of convective cloud forcing, sea surface temperature, and insolation in the central Pacific. Symposium on the Regulation of Sea Surface Temperatures and Warming of the Tropical Ocean Atmosphere System, American Meteorological Society, Boston, MA, 9–12
- Flato GM, Hibler WD III (1990) On a simple sea-ice dynamics model for climate studies. Annals Glaciol 14:72–77
Google Scholar - Gutzler DS, Kiladis GN, Meehl GA, Weickmann KM, Wheeler M (1994) The global climate of December 1992–February 1993. Part II. Large-scale variability across the tropical western Pacific during TOGA COARE. J Clim 7:1606–1622
Google Scholar - Harrison DE, Gutzler DS (1986) Variability of monthly-averaged surface and 850 mb winds at tropical Pacific islands. Mon Weather Rev 114:285–294
Google Scholar - Hurrell JW (1995) Comparison of NCAR Community Climate Model (CCM) climates. Clim Dyn 11:25–50
Google Scholar - Inamdar AK, Ramanathan V (1994) Physics of greenhouse effect and convection in warm oceans. J Clim 7:715–731
Google Scholar - Krishnamurti TN, Bedi HS, Subramanian M (1989) The summer monsoon of 1987. J Clim 4:321–340
Google Scholar - Krishnamurti TN, Bedi HS, Subramanian M (1990) The summer monsoon of 1988. Meteorol Atmos Phys 42:19–37
Google Scholar - Levitus S (1982) Climatological Atlas of the World Ocean. NOAA Prof Pap 14, National Oceanic and Atmospheric Administration, Washington, DC
Google Scholar - Meehl GA (1989) The coupled ocean-atmosphere modeling problem in the tropical Pacific and Asian monsoon regions. J Clim 2:1146–1163
Google Scholar - Meehl GA (1994) Influence of the land surface in the Asian summer monsoon: external conditions versus internal feedbacks. J Clim 7:1033–1049
Google Scholar - Meehl GA, Washington WM (1990) CO2 climate sensitivity and snow-sea-ice albedo parameterization in an atmospheric GCM coupled to a mixed-layer ocean model. Clim Change 16:283–306
Google Scholar - Ramanathan V, Collins W (1991) Thermodynamic regulation of ocean warming by cirrus clouds deduced from the 1987 El Niño. Nature 351:27–32
Google Scholar - Semtner AJ (1976) A model for the thermodynamic growth of sea ice in numerical investigations of climate. J Phys Oceanogr 6:379–389
Article Google Scholar - Senior CA, Mitchell JFB (1993) Carbon dioxide and climate: the impact of cloud parameterization. J Clim 6:393–418
Google Scholar - Senior CA, Mitchell JFB, LeTreut H, Li Z-X (1991) The impact of resolution on the simulation of cloud and radiation. In: Modelling changes in climate due to enhanced CO2, the role of atmospheric dynamics, cloud and moisture (Climate Res Tech Note 13). Hadley Centre, Meteorological Office, Bracknell, UK
Google Scholar - Sun D, Lindzen RS (1993) Distribution of tropical tropospheric water vapor. J Atmos Sci 50:1643–1660
Google Scholar - Trenberth KE, Large WG, Olson JG (1990) The mean annual cycle in global ocean wind stress. J Phys Oceanogr 20:1742–1760
Google Scholar - van Loon H, Madden RA (1981) The Southern Oscillation. Part I: global associations with pressure and temperature in northern winter. Mon Weather Rev 109:1150–1162
Google Scholar - Waliser DE, Graham NE, Gautier C (1993) Comparison of the highly reflective cloud and outgoing longwave radiation datasets for use in estimating tropical deep convection. J Clim 6:331–353
Google Scholar - Washington WM, Meehl GA (1989) Climate sensitivity due to increased CO2: experiments with a coupled atmosphere and ocean general circulation model. Clim Dyn 4:1–38
Google Scholar - Washington WM, Meehl GA (1993) Greenhouse sensitivity experiments with penetrative cumulus convection and tropical cirrus albedo effects. Clim Dyn 8:211–223
Google Scholar - Washington WM, Meehl GA, VerPlank L, Bettge T (1994) A world ocean model for greenhouse sensitivity studies: resolution intercomparison and the role of diagnostic forcing. Clim Dyn 9:321–344
Google Scholar
Author information
Authors and Affiliations
- National Center for Atmospheric Research, 80307-3000, Boulder, Colorado, USA
Gerald A. Meehl & Warren M. Washington
Authors
- Gerald A. Meehl
- Warren M. Washington
Additional information
Support is provided by the Office of Health and Environmental Research of the U.S. Department of Energy, as part of its Carbon Dioxide Research Program.
The National Center for Atmospheric Research is sponsored by the National Science Foundation.
Rights and permissions
About this article
Cite this article
Meehl, G.A., Washington, W.M. Cloud albedo feedback and the super greenhouse effect in a global coupled GCM.Climate Dynamics 11, 399–411 (1995). https://doi.org/10.1007/BF00209514
- Received: 03 August 1994
- Accepted: 21 March 1995
- Issue date: September 1995
- DOI: https://doi.org/10.1007/BF00209514