Publications des scientifiques de l'IRD

Vinour L., Jullien S., Mouche A., Combot C., Mangeas Morgan. (2021). Observations of tropical cyclone inner-core fine-scale structure, and its link to intensity variations. Journal of the Atmospheric Sciences, 78 (11), 3651-3671. ISSN 0022-4928.

Titre du document
Observations of tropical cyclone inner-core fine-scale structure, and its link to intensity variations
Année de publication
2021
Type de document
Article référencé dans le Web of Science WOS:000757428000014
Auteurs
Vinour L., Jullien S., Mouche A., Combot C., Mangeas Morgan
Source
Journal of the Atmospheric Sciences, 2021, 78 (11), 3651-3671 ISSN 0022-4928
Tropical cyclone (TC) internal dynamics have emerged over recent decades as a key to understand their intensity variations, but they are difficult to observe because they are sporadic, multiscale, and occur in areas of very strong wind gradients. The present work aims at describing the internal structure of TCs, as observed with newly available satellite synthetic aperture radar (SAR) wind products, and at evaluating relations between this structure and the TC life cycle. It is based on a unique dataset of 188 SAR high-resolution (1 km) images, containing 15-47 images by intensity category. An extraction method is designed to retrieve and characterize the TC radial profile, its azimuthal degree of asymmetry, and the energy distribution in the eyewall and maximum wind areas. Vortex contraction and sharpening of the eyewall wind radial gradient with increasing TC intensity are observed, as well as a symmetrization of energy distribution around the vortex. Eyewall high-wavenumber structures show a dependence on the life-cycle phase, supporting previous findings discussing the vortex rapid evolution with onset and propagation of eyewall mesovortices and associated vortex Rossby wave generation. A machine-learning approach highlights that the eye shape and eyewall radial wind gradient fine-scale dynamics have the potential to improve the statistical prediction of TC intensity variations relative to the sole use of vortexaveraged parameters and synoptic information. The high-resolution radial and azimuthal coverage provided by SARs make these acquisitions a very valuable tool for TC research and operational application.
Plan de classement
Sciences fondamentales / Techniques d'analyse et de recherche [020] ; Sciences du milieu [021] ; Télédétection [126]
Description Géographique
ATLANTIQUE ; PACIFIQUE ; OCEAN INDIEN ; ZONE TROPICALE
Localisation
Fonds IRD [F B010084336]
Identifiant IRD
fdi:010084336
Contact