How may low-cloud radiative properties simulated in the current climate influence low-cloud feedbacks under global warming? - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Geophysical Research Letters Année : 2012

How may low-cloud radiative properties simulated in the current climate influence low-cloud feedbacks under global warming?

Résumé

The influence of cloud modelling uncertainties on the projection of the tropical low-cloud response to global warming is explored by perturbing model parameters of the IPSL-CM5A climate model in a range of configurations (realistic general circulation model, aqua-planet, single-column model). While the positive sign and the mechanism of the low-cloud response to climate warming predicted by the model are robust, the amplitude of the response can vary considerably depending on the model tuning parameters. Moreover, the strength of the low-cloud response to climate change exhibits a strong correlation with the strength of the low-cloud radiative effects simulated in the current climate. We show that this correlation primarily results from a local positive feedback (referred to as the "beta feedback") between boundary-layer cloud radiative cooling, relative humidity and low-cloud cover. Based on this correlation and observational constraints, it is suggested that the strength of the tropical low-cloud feedback predicted by the IPSL-CM5A model in climate projections might be overestimated by about fifty percent. © 2012. American Geophysical Union. All Rights Reserved.
Fichier principal
Vignette du fichier
Brient_et_al-2012-Geophysical_Research_Letters.pdf (342.04 Ko) Télécharger le fichier
Origine : Fichiers éditeurs autorisés sur une archive ouverte
Loading...

Dates et versions

hal-01113123 , version 1 (04-02-2015)

Identifiants

Citer

F. Brient, S. Bony. How may low-cloud radiative properties simulated in the current climate influence low-cloud feedbacks under global warming?. Geophysical Research Letters, 2012, 39 (20), pp.L20807. ⟨10.1029/2012GL053265⟩. ⟨hal-01113123⟩
571 Consultations
138 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More