Impact of Convective Organization on the Response of Tropical Precipitation Extremes to Warming

Caroline Muller 1, 2, *
* Auteur correspondant
1 AOS Program - Atmospheric and Oceanic Sciences Program [Princeton]
GFDL - NOAA Geophysical Fluid Dynamics Laboratory, Princeton University
Abstract : In this study the response of tropical precipitation extremes to warming in organized convection is examined using a cloud-resolving model. Vertical shear is imposed to organize the convection into squall lines. Earlier studies show that in disorganized convection, the fractional increase of precipitation extremes is similar to that of surface water vapor, which is substantially smaller than the increase in column water vapor. It has been suggested that organized convection could lead to stronger amplifications. Regardless of the strength of the shear, amplifications of precipitation extremes in the cloud-resolving simulations are comparable to those of surface water vapor and are substantially less than increases in column water vapor. The results without shear and with critical shear, for which the squall lines are perpendicular to the shear, are surprisingly similar with a fractional rate of increase of precipitation extremes slightly smaller than that of surface water vapor. Interestingly, the dependence on shear is nonmonotonic, and stronger supercritical shear yields larger rates, close to or slightly larger than surface humidity. A scaling is used to evaluate the thermodynamic and dynamic contributions to precipitation extreme changes. To first order, they are dominated by the thermodynamic component, which has the same magnitude for all shears, close to the change in surface water vapor. The dynamic contribution plays a secondary role and tends to weaken extremes without shear and with critical shear, while it strengthens extremes with supercritical shear. These different dynamic contributions for different shears are due to different responses of convective mass fluxes in individual updrafts to warming.
Type de document :
Article dans une revue
Journal of Climate, American Meteorological Society, 2013, 26 (14), pp.5028-5043. 〈10.1175/jcli-d-12-00655.1〉
Liste complète des métadonnées

Littérature citée [39 références]  Voir  Masquer  Télécharger

https://hal-polytechnique.archives-ouvertes.fr/hal-00995152
Contributeur : Denis Roura <>
Soumis le : mardi 27 mai 2014 - 15:25:17
Dernière modification le : jeudi 10 mai 2018 - 02:03:50
Document(s) archivé(s) le : mercredi 27 août 2014 - 10:42:06

Fichier

jcli-d-12-006552E1.pdf
Fichiers éditeurs autorisés sur une archive ouverte

Identifiants

Collections

Citation

Caroline Muller. Impact of Convective Organization on the Response of Tropical Precipitation Extremes to Warming. Journal of Climate, American Meteorological Society, 2013, 26 (14), pp.5028-5043. 〈10.1175/jcli-d-12-00655.1〉. 〈hal-00995152〉

Partager

Métriques

Consultations de la notice

184

Téléchargements de fichiers

102