Mesoscale model cloud scheme assessment using satellite observations - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Journal of Geophysical Research: Atmospheres Année : 2002

Mesoscale model cloud scheme assessment using satellite observations

Résumé

An exploratory evaluation of the explicit cloud scheme of the mesoscale nonhydrostatic (Meso-NH) model has been conducted by comparing synthetic METEOSAT brightness temperatures (BT) to the observed ones. Three different meteorological situations are examined to illustrate the expected degree of accuracy in simulating realistic synthetic BTs in the midlatitude and in the subtropics, with a horizontal grid length ranging from 75 to 12 km. It is shown that the model to satellite approach, which combines the output from a bulk explicit cloud scheme routinely used in mesoscale simulations with a detailed radiative transfer code, offers the possibility of tuning a critical parameter. For instance, tests made with three different values of an ice to snow autoconversion threshold reveal a profound impact on the synthetic BT maps which results in unbiased differences with satellite observations when the appropriate value is selected. The main discrepancies that remain are partly due to errors in the vertical or horizontal placement of the cloud layer or in the amount of condensates, but also due to the lack of subgrid-scale cloudiness in the model. A similar test conducted on the ice water and the liquid water paths confirms the fairly good agreement with retrievals from microwave observations. The paper concludes by discussing the need not only to extend the model to satellite approach to other well-documented cases but also to derive diagnostics from deep convection scheme characteristics in order to include the radiative effect of the convective towers in the generation of synthetic BT maps.
Fichier principal
Vignette du fichier
chaboureau_etal_jgr2002_4301.pdf (9.57 Mo) Télécharger le fichier
Origine Fichiers éditeurs autorisés sur une archive ouverte
Licence
Copyright (Tous droits réservés)

Dates et versions

hal-04254889 , version 1 (23-10-2023)

Licence

Copyright (Tous droits réservés)

Identifiants

Citer

Jean‐pierre Chaboureau, Jean‐pierre Cammas, Patrick J Mascart, Jean‐pierre Pinty, Jean‐philippe Lafore. Mesoscale model cloud scheme assessment using satellite observations. Journal of Geophysical Research: Atmospheres, 2002, 107 (D16), pp.AAC 8-1-AAC 8-20. ⟨10.1029/2001jd000714⟩. ⟨hal-04254889⟩
13 Consultations
9 Téléchargements

Altmetric

Partager

Gmail Mastodon Facebook X LinkedIn More