1. CGILS: Results from the first phase of an international project to understand the physical mechanisms of low cloud feedbacks in single column models
- Author
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Zhang, Minghua, Blossey, Peter N., Khairoutdinov, Marat F., Austin, Phillip H., Bacmeister, Julio T., Bony, Sandrine, Brient, Florent, Cheedela, Suvarchal K., Del Genio, Anthony D., De Roode, Stephan R., Endo, Satoshi, Golaz, Jean-Christophe, Stevens, Bjorn, Isotta, Francesco Alessandro, Franklin, Charmaine N., Cheng, Anning, Kang, In-Sik, Kawai, Hideaki, Liu, Yangang, Xu, Kuan-Man, Koehler, Martin, Lock, Adrian P., Molod, Andrea M., Hannay, Cecile, Zhao, Ming, Lohmann, Ulrike, Neggers, Roel A. J., Rasch, Philip, Sandu, Irina, Siegenthaler-Le Drian, Colombe, Senkbeil, Ryan, Heus, Thijs, Bretherton, Christopher S., Suarez, Max J., Wolf, Audrey, Siebesma, A. Pier, von Salzen, Knut, Webb, Mark J., Larson, Vincent E., Dufresne, Jean-Louis, Institute for Terrestrial and Planetary Atmospheres [Stony Brook] (ITPA), School of Marine and Atmospheric Sciences [Stony Brook] (SoMAS), Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY)-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY), Univ Washington, Dept Atmospher Sci, Seattle, WA 98195 USA, Univ British Columbia, Dept Earth & Ocean Sci, Vancouver, BC V5Z 1M9, Canada, NOAA Earth System Research Laboratory (ESRL), National Oceanic and Atmospheric Administration (NOAA), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École des Ponts ParisTech (ENPC)-École polytechnique (X)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Max-Planck-Institut für Meteorologie (MPI-M), Max-Planck-Gesellschaft, NASA Goddard Institute for Space Studies (GISS), NASA Goddard Space Flight Center (GSFC), Department of Geoscience and Remote Sensing [Delft], Delft University of Technology (TU Delft), Brookhaven Natl Lab, Dept Environm Sci, Upton, NY 11973 USA, NOAA Geophysical Fluid Dynamics Laboratory (GFDL), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), CSIRO, Ctr Australian Weather & Climate Res, Aspendale, Vic, Australia, NASA Langley Research Center [Hampton] (LaRC), Seoul Natl Univ, Sch Earth & Environm Sci, Seoul, South Korea, Meteorol Res Inst, Tsukuba, Ibaraki 305, Japan, European Centre for Medium-Range Weather Forecasts (ECMWF), Met Off Hadley Ctr, Exeter, Devon, England, Global Modeling and Assimilation Office (GMAO), Royal Netherlands Meteorological Institute (KNMI), Pacific NW Natl Lab, Richland, WA 99352 USA, Univ Wisconsin, Dept Math Sci, Milwaukee, WI 53201 USA, Canadian Ctr Climate Modelling & Anal, Victoria, BC, Canada, Department of Atmospheric Sciences [Seattle], University of Washington [Seattle], Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)
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[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere ,large eddy models ,low cloud feedbacks ,single column models ,CGILS - Abstract
International audience; CGILS-the CFMIP-GASS Intercomparison of Large Eddy Models (LESs) and single column models (SCMs)-investigates the mechanisms of cloud feedback in SCMs and LESs under idealized climate change perturbation. This paper describes the CGILS results from 15 SCMs and 8 LES models. Three cloud regimes over the subtropical oceans are studied: shallow cumulus, cumulus under stratocumulus, and well-mixed coastal stratus/stratocumulus. In the stratocumulus and coastal stratus regimes, SCMs without activated shallow convection generally simulated negative cloud feedbacks, while models with active shallow convection generally simulated positive cloud feedbacks. In the shallow cumulus alone regime, this relationship is less clear, likely due to the changes in cloud depth, lateral mixing, and precipitation or a combination of them. The majority of LES models simulated negative cloud feedback in the well-mixed coastal stratus/stratocumulus regime, and positive feedback in the shallow cumulus and stratocumulus regime. A general framework is provided to interpret SCM results: in a warmer climate, the moistening rate of the cloudy layer associated with the surface-based turbulence parameterization is enhanced; together with weaker large-scale subsidence, it causes negative cloud feedback. In contrast, in the warmer climate, the drying rate associated with the shallow convection scheme is enhanced. This causes positive cloud feedback. These mechanisms are summarized as the "NESTS" negative cloud feedback and the "SCOPE" positive cloud feedback (Negative feedback from Surface Turbulence under weaker Subsidence-Shallow Convection PositivE feedback) with the net cloud feedback depending on how the two opposing effects counteract each other. The LES results are consistent with these interpretations.
- Published
- 2013
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