The extreme 2014 flood in south-western Amazon basin: the role of tropical-subtropical South Atlantic SST gradient

• Autores: Espinoza, Jhan Carlo, Marengo, José Antonio, Ronchail, Josyane, Molina Carpio, Jorge, Noriega Flores, Luis, Guyot, Jean Loup
• Formato: artículo
• Fecha de Publicación: 2014
• Institución: Instituto Geofísico del Perú
• Repositorio: IGP-Institucional
• Lenguaje: inglés
• OAI Identifier: oai:repositorio.igp.gob.pe:20.500.12816/2916
• Enlace del recurso: http://hdl.handle.net/20.500.12816/2916; https://doi.org/10.1088/1748-9326/9/12/124007
• Nivel de acceso: acceso abierto
• Materia: Extreme flood; Amazon basin; Madeira river; Bolivian Amazon; Brazilian Amazon; http://purl.org/pe-repo/ocde/ford#1.05.00; http://purl.org/pe-repo/ocde/ford#1.05.09

Unprecedented wet conditions are reported in the 2014 summer (December–March) in Southwestern Amazon, with rainfall about 100% above normal. Discharge in the Madeira River (the main southern Amazon tributary) has been 74% higher than normal (58 000 m³ s⁻¹) at Porto Velho and 380% (25 000 m³ s⁻¹) at Rurrenabaque, at the exit of the Andes in summer, while levels of the Rio Negro at Manaus were 29.47 m in June 2014, corresponding to the fifth highest record during the 113 years record of the Rio Negro. While previous floods in Amazonia have been related to La Niña and/or warmer than normal tropical South Atlantic, the 2014 rainfall and flood anomalies are associated with warm condition in the western Pacific-Indian Ocean and with an exceptionally warm Subtropical South Atlantic. Our results suggest that the tropical and subtropical South Atlantic SST gradient is a main driver for moisture transport from the Atlantic toward southwestern Amazon, and this became exceptionally intense during summer of 2014.