The 'too few, too bright' tropical low-cloud problem in CMIP5 models - Université Pierre et Marie Curie Accéder directement au contenu
Article Dans Une Revue Geophysical Research Letters Année : 2012

The 'too few, too bright' tropical low-cloud problem in CMIP5 models

Résumé

Previous generations of climate models have been shown to under-estimate the occurrence of tropical low-level clouds and to over-estimate their radiative effects. This study analyzes outputs from multiple climate models participating in the Fifth phase of the Coupled Model Intercomparison Project (CMIP5) using the Cloud Feedback Model Intercomparison Project Observations Simulator Package (COSP), and compares them with different satellite data sets. Those include CALIPSO lidar observations, PARASOL mono-directional reflectances and CERES radiative fluxes at the top of the atmosphere. We show that current state-of-the-art climate models predict overly bright low-clouds, even for a correct low-cloud cover. The impact of these biases on the Earth' radiation budget, however, is reduced by compensating errors. Those include the tendency of models to under-estimate the low-cloud cover and to overestimate the occurrence of mid-and high-clouds above low-clouds. Finally, we show that models poorly represent the dependence of the vertical structure of low-clouds on large-scale environmental conditions. The implications of this 'too few, too bright low-cloud problem' for climate sensitivity and model development are discussed. Citation: Nam, C., S. Bony, J.-L. Dufresne, and H. Chepfer (2012), The 'too few, too bright' tropical low-cloud problem in CMIP5 models, Geophys. Res. Lett., 39, L21801, doi: 10.1029/2012GL053421.
Fichier principal
Vignette du fichier
Nam_et_al-2012-Geophysical_Research_Letters.pdf (636.3 Ko) Télécharger le fichier
Origine : Fichiers éditeurs autorisés sur une archive ouverte
Loading...

Dates et versions

hal-01115803 , version 1 (11-02-2015)

Identifiants

Citer

Christine Nam, Sandrine Bony, Jean-Louis Dufresne, H. Chepfer. The 'too few, too bright' tropical low-cloud problem in CMIP5 models. Geophysical Research Letters, 2012, 39 (21), pp.L21801. ⟨10.1029/2012GL053421⟩. ⟨hal-01115803⟩
518 Consultations
482 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More