Inter-El Niño variability and its impact on the South American low-level jet east of the Andes during austral summer ? two case studies - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Advances in Geosciences Année : 2006

Inter-El Niño variability and its impact on the South American low-level jet east of the Andes during austral summer ? two case studies

Résumé

The impact of the maximum convection location over eastern and central Equatorial Pacific over the intensity and positioning of the South American Low-Level Jet east of the Andes (SALLJ) during the austral summer was investigated. The Bonner criteria 1 was applied to the NCEP-NCAR circulation fields during the El Niño of 1997/1998 and 2002/2003 to identify the SALLJ episodes. The composites of the atmospheric circulation over the South America during El Niño events showed that the SALLJ can be influenced by small displacements of the quasi-stationary Rossby waves position. During the strong El Niño event of 1997/1998 the SALLJ is maintained by the eastern trade winds. A low-level anomalous anticyclonic circulation over the central part of Brazil enhanced the wind in the nucleus of the jet and displaced its axis to the Northern Argentina and South of Brazil. However, the northern trade winds seem to maintain the SALLJ during the weak El Niño of 2002/2003. The jet was weaker and displaced more southeastward of Brazil than during the strong event.
Fichier principal
Vignette du fichier
adgeo-6-283-2006.pdf (330.14 Ko) Télécharger le fichier
Origine : Accord explicite pour ce dépôt
Loading...

Dates et versions

hal-00296948 , version 1 (18-06-2008)

Identifiants

  • HAL Id : hal-00296948 , version 1

Citer

G. A. M. Silva, T. Ambrizzi. Inter-El Niño variability and its impact on the South American low-level jet east of the Andes during austral summer ? two case studies. Advances in Geosciences, 2006, 6, pp.283-287. ⟨hal-00296948⟩

Collections

INSU EGU
95 Consultations
231 Téléchargements

Partager

Gmail Facebook X LinkedIn More