Junquas Clémentine, Li L., Vera C. S., Le Treut H., Takahashi K. (2016). Influence of South America orography on summertime precipitation in Southeastern South America [+Erratum]. Climate Dynamics, 46 (11-12), p. 3941-3963 [+erratum 2016,vol. 47,no 9-10, p. 3889-3890]. ISSN 0930-7575.
Titre du document
Influence of South America orography on summertime precipitation in Southeastern South America [+Erratum]
Année de publication
2016
Auteurs
Junquas Clémentine, Li L., Vera C. S., Le Treut H., Takahashi K.
Source
Climate Dynamics, 2016,
46 (11-12), p. 3941-3963 [+erratum 2016,vol. 47,no 9-10, p. 3889-3890] ISSN 0930-7575
Impacts of the main South American orographic structures (the Andes, the Brazilian Plateau and the Guiana shield) on the regional climate and associated global teleconnection are investigated through numerical experiments in which some of these features are suppressed. Simulations are performed with a "two-way nesting" system coupling interactively the regional and global versions of the LMDZ4 atmospheric general circulation model. At regional scale, the simulations confirm previous studies, showing that both the Andes and the Brazilian Plateau exert a control on the position and strength of the South Atlantic convergence zone (SACZ), mainly through their impact on the low-level jet and the coastal branch of the subtropical anticyclones. The northern topography of South America appears to be crucial to determine the leading mode of rainfall variability in eastern South America, which manifests itself as a dipole-like pattern between Southeastern South America and the SACZ region. The suppression of South America orography also shows global-scale effects, corresponding to an adjustment of the global circulation system. Changes in atmospheric circulation and precipitation are found in remote areas on the globe, being the consequences of various teleconnection mechanisms. When the Brazilian Plateau and the Andes are suppressed, there is a decrease of precipitation in the SACZ region, associated with a weakening of the large-scale ascendance. Changes are described in terms of anomalies in the Walker circulation, meridional displacements of the mid-latitude jet stream, Southern annular mode anomalies and modifications of Rossby wave train teleconnection processes.
Plan de classement
Sciences du milieu [021]
;
Limnologie physique / Océanographie physique [032]
;
Hydrologie [062]
;
Géologie et formations superficielles [064]
Description Géographique
AMERIQUE DU SUD ; ANDES ; BRESIL PLATEAU ; GUYANE PLATEAU ; BOLIVIE ; ARGENTINE ; CHILI ; URUGUAY ; PEROU
Localisation
Fonds IRD [F B010067758]
Identifiant IRD
fdi:010067758
