Publications des scientifiques de l'IRD

Samson G., Masson S., Lengaigne Matthieu, Keerthi M. G., Vialard Jérôme, Pous S., Madec G., Jourdain N. C., Jullien S., Menkès Christophe, Marchesiello Patrick. (2014). The NOW regional coupled model : application to the tropical Indian Ocean climate and tropical cyclone activity. Journal of Advances in Modeling Earth Systems, 6 (3), p. 700-722. ISSN 1942-2466.

Titre du document
The NOW regional coupled model : application to the tropical Indian Ocean climate and tropical cyclone activity
Année de publication
2014
Type de document
Article référencé dans le Web of Science WOS:000344387900013
Auteurs
Samson G., Masson S., Lengaigne Matthieu, Keerthi M. G., Vialard Jérôme, Pous S., Madec G., Jourdain N. C., Jullien S., Menkès Christophe, Marchesiello Patrick
Source
Journal of Advances in Modeling Earth Systems, 2014, 6 (3), p. 700-722 ISSN 1942-2466
This paper presents the NOW regional coupled ocean-atmosphere model built from the NEMO ocean and WRF atmospheric numerical models. This model is applied to the tropical Indian Ocean, with the oceanic and atmospheric components sharing a common 1/4 degrees horizontal grid. Long experiments are performed over the 1990-2009 period using the Betts-Miller-Janjic (BMJ) and Kain-Fritsch (KF) cumulus parameterizations. Both simulations produce a realistic distribution of seasonal rainfall and a realistic northward seasonal migration of monsoon rainfall over the Indian subcontinent. At subseasonal time scales, the model reasonably reproduces summer monsoon active and break phases, although with underestimated rainfall and surface wind signals. Its relatively high resolution results in realistic spatial and seasonal distributions of tropical cyclones, but it fails to reproduce the strongest observed cyclone categories. At interannual time scales, themodel reproduces the observed variability associated with the Indian Ocean Dipole (IOD) and the delayed basin-wide warming/cooling induced by the El Nino Southern Oscillation (ENSO). The timing of IOD occurrence in the model generally matches that of the observed events, confirming the influence of ENSO on the IOD development (through the effect of lateral boundary conditions in our simulations). Although the KF and BMJ simulations share a lot in common, KF strongly overestimates rainfall at all time scales. KF also overestimates the number of simulated cyclones by a factor two, while simulating stronger events (up to 55 m s(-1)) compared to BMJ (up to 40 m s(-1)). These results could be related to an overly active cumulus parameterization in KF.
Plan de classement
Sciences fondamentales / Techniques d'analyse et de recherche [020] ; Sciences du milieu [021] ; Limnologie physique / Océanographie physique [032]
Description Géographique
OCEAN INDIEN ; ZONE TROPICALE
Localisation
Fonds IRD [F B010062681]
Identifiant IRD
fdi:010062681
Contact