Publications des scientifiques de l'IRD

Jullien S., Marchesiello Patrick, Menkès Christophe, Lefèvre Jérôme, Jourdain N. C., Samson G., Lengaigne Matthieu. (2014). Ocean feedback to tropical cyclones : climatology and processes. Climate Dynamics, 43 (9-10), p. 2831-2854. ISSN 0930-7575.

Titre du document
Ocean feedback to tropical cyclones : climatology and processes
Année de publication
2014
Type de document
Article référencé dans le Web of Science WOS:000344480100028
Auteurs
Jullien S., Marchesiello Patrick, Menkès Christophe, Lefèvre Jérôme, Jourdain N. C., Samson G., Lengaigne Matthieu
Source
Climate Dynamics, 2014, 43 (9-10), p. 2831-2854 ISSN 0930-7575
This study presents the first multidecadal and coupled regional simulation of cyclonic activity in the South Pacific. The long-term integration of state-of the art models provides reliable statistics, missing in usual event studies, of air-sea coupling processes controlling tropical cyclone (TC) intensity. The coupling effect is analyzed through comparison of the coupled model with a companion forced experiment. Cyclogenesis patterns in the coupled model are closer to observations with reduced cyclogenesis in the Coral Sea. This provides novel evidence of air-sea coupling impacting not only intensity but also spatial cyclogenesis distribution. Storm-induced cooling and consequent negative feedback is stronger for regions of shallow mixed layers and thin or absent barrier layers as in the Coral Sea. The statistical effect of oceanic mesoscale eddies on TC intensity (crossing over them 20 % of the time) is also evidenced. Anticyclonic eddies provide an insulating effect againststorm-induced upwelling and mixing and appear to reduce sea surface temperature (SST) cooling. Cyclonic eddies on the contrary tend to promote strong cooling, particularly through storm-induced upwelling. Air-sea coupling is shown to have a significant role on the intensification process but the sensitivity of TCs to SST cooling is nonlinear and generally lower than predicted by thermodynamic theories: about 15 rather than over 30 hPa degrees C-1 and only for strong cooling. The reason is that the cooling effect is not instantaneous but accumulated over time within the TC inner-core. These results thus contradict the classical evaporation-wind feedback process as being essential to intensification and rather emphasize the role of macro-scale dynamics.
Plan de classement
Sciences fondamentales / Techniques d'analyse et de recherche [020] ; Sciences du milieu [021] ; Limnologie physique / Océanographie physique [032]
Description Géographique
ZONE TROPICALE ; PACIFIQUE SUD
Localisation
Fonds IRD [F B010062700]
Identifiant IRD
fdi:010062700
Contact