Simulated seasonal and interannual variability of the mixed layer heat budget in the Northern Indian Ocean - CNRS - Centre national de la recherche scientifique Accéder directement au contenu
Article Dans Une Revue Journal of Climate Année : 2007

Simulated seasonal and interannual variability of the mixed layer heat budget in the Northern Indian Ocean

Résumé

A global ocean general circulation model (OGCM) is used to investigate the mixed layer heat budget of the northern Indian Ocean (NIO). The model is validated against observations and shows fairly goodagreement with mixed layer depth data in the NIO. The NIO has been separated into three subbasins: the western Arabian Sea (AS), the eastern AS, and the Bay of Bengal (BoB). This study reveals strongdifferences between the western and eastern AS heat budget, while the latter basin has similarities with the BoB. Interesting new results on seasonal time scales are shown. The penetration of solar heat flux needs tobe taken into account for two reasons. First, an average of 28 W m$^{-2}$ is lost beneath the mixed layer over the year. Second, the penetration of solar heat flux tends to reduce the effect of solar heat flux on the SSTseasonal cycle in the AS because the seasons of strongest flux are also seasons with a thin mixed layer. This enhances the control of SST seasonal variability by latent heat flux. The impact of salinity on SST variabilityis demonstrated. Salinity stratification plays a clear role in maintaining a high winter SST in the BoB and eastern AS while not in the western AS. The presence of freshwater near the surface allows heat storagebelow the surface layer that can later be recovered by entrainment warming during winter cooling (with a winter contribution of $\pm$2.1°C in the BoB). On an interannual time scale, the eastern AS and BoB arestrongly controlled by the winds through the latent heat flux anomalies. In the western AS, vertical processes, as well as horizontal advection, contribute significantly to SST interannual variability, and the windis not the only factor controlling the heat flux forcing
Fichier principal
Vignette du fichier
[15200442 - Journal of Climate] Simulated Seasonal and Interannual Variability of the Mixed Layer Heat Budget in the Northern Indian Ocean.pdf (2.21 Mo) Télécharger le fichier
Origine : Fichiers éditeurs autorisés sur une archive ouverte

Dates et versions

hal-00280370 , version 1 (10-06-2021)

Identifiants

Citer

Clément de Boyer Montégut, Jérôme Vialard, S. S. C. Shenoi, D. Shankar, Fabien Durand, et al.. Simulated seasonal and interannual variability of the mixed layer heat budget in the Northern Indian Ocean. Journal of Climate, 2007, 20, pp.3249-3268. ⟨10.1175/JCLI4148.1⟩. ⟨hal-00280370⟩
162 Consultations
40 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More