edu.ucar.opensky::articles:13240 UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact 2025-12-26T03:36:10.493118 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) https://n2t.org/ark:/85065/d70z746s CGILS: Results from the first phase of an international project to understand the physical mechanisms of low cloud feedbacks in single column models 2013-12-01T00:00:00Z publication https://n2t.org/ark:/85065/d70z746s https://doi.org/10.1002/2013MS000246 Zhang, M. author BRETHERTON, C. author Blossey, P. author Austin, P. author Bacmeister, Julio author Bony, S. author Brient, F. author Cheedela, S. author Cheng, A. author Del Genio, A. author De Roode, S. author Endo, S. author Franklin, C. author Golaz, J. author Hannay, Cecile E. author Heus, T. author Isotta, F. author Dufresne, J. author Kang, I. author Kawai, H. author Köhler, M. author Larson, V. author Liu, Y. author Lock, A. author Lohmann, U. author KHAIROUTDINOV, M. author Molod, A. author Neggers, R. author Rasch, P. author Sandu, I. author Senkbeil, R. author Siebesma, A. author Siegenthaler-Le Drian, C. author Stevens, B. author Suarez, M. author Xu, K. author von Salzen, K. author Webb, M. author Wolf, A. author Zhao, M. author UCAR/NCAR - Library publisher 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. UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact PDF Text theme Resource Type 2016-01-01T00:00:00Z publication Copyright 2013 American Geophysical Union. None eng geoscientificInformation