Revisiting wintertime cold air intrusions at the east of the Andes: Propagating features from subtropical Argentina to Peruvian Amazon and relationship with large-scale circulation patterns

This study investigates the spatial and temporal characteristics of cold surges that propagates northward along the eastern flank of the Andes from subtropical to tropical South America analysing wintertime in situ daily minimum temperature observations from Argentina, Bolivia and Peru and ERA-40 re...

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Autor principal:	Bettolli, María Laura
Publicado:	2013
Materias:	Argentina Bolivian Amazon Circulation patterns Cold surges Low-level winds Peruvian Amazon Self-organizing maps air temperature atmospheric circulation atmospheric dynamics cold air spatiotemporal analysis troposphere winter Amazonia Andes Bolivia La Plata Basin Peru
Acceso en línea:	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_09307575_v41_n7-8_p1983_Espinoza http://hdl.handle.net/20.500.12110/paper_09307575_v41_n7-8_p1983_Espinoza
Aporte de:	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires

id	paper:paper_09307575_v41_n7-8_p1983_Espinoza
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spelling	paper:paper_09307575_v41_n7-8_p1983_Espinoza2023-06-08T15:52:43Z Revisiting wintertime cold air intrusions at the east of the Andes: Propagating features from subtropical Argentina to Peruvian Amazon and relationship with large-scale circulation patterns Bettolli, María Laura Argentina Bolivian Amazon Circulation patterns Cold surges Low-level winds Peruvian Amazon Self-organizing maps air temperature atmospheric circulation atmospheric dynamics cold air spatiotemporal analysis troposphere winter Amazonia Andes Argentina Bolivia La Plata Basin Peru This study investigates the spatial and temporal characteristics of cold surges that propagates northward along the eastern flank of the Andes from subtropical to tropical South America analysing wintertime in situ daily minimum temperature observations from Argentina, Bolivia and Peru and ERA-40 reanalysis over the 1975-2001 period. Cold surges usually last 2 or 3 days but are generally less persistent in the southern La Plata basin compared to tropical regions. On average, three to four cold surges are reported each year. Our analysis reveals that 52 % of cold episodes registered in the south of La Plata basin propagate northward to the northern Peruvian Amazon at a speed of around 20 m s-1. In comparison to cold surges that do not reach the tropical region, we demonstrate that these cold surges are characterized, before they reach the tropical region, by a higher occurrence of a specific circulation pattern associated to southern low-level winds progression toward low latitudes combined with subsidence and dry condition in the middle and low troposphere that reinforce the cold episode through a radiative effect. Finally, the relationship between cold surges and atmosphere dynamics is illustrated for the two most severe cold intrusions that reached the Peruvian and Bolivian Amazon in the last 20 years. © 2012 Springer-Verlag Berlin Heidelberg. Fil:Bettolli, M.L. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2013 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_09307575_v41_n7-8_p1983_Espinoza http://hdl.handle.net/20.500.12110/paper_09307575_v41_n7-8_p1983_Espinoza
institution	Universidad de Buenos Aires
institution_str	I-28
repository_str	R-134
collection	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic	Argentina Bolivian Amazon Circulation patterns Cold surges Low-level winds Peruvian Amazon Self-organizing maps air temperature atmospheric circulation atmospheric dynamics cold air spatiotemporal analysis troposphere winter Amazonia Andes Argentina Bolivia La Plata Basin Peru
spellingShingle	Argentina Bolivian Amazon Circulation patterns Cold surges Low-level winds Peruvian Amazon Self-organizing maps air temperature atmospheric circulation atmospheric dynamics cold air spatiotemporal analysis troposphere winter Amazonia Andes Argentina Bolivia La Plata Basin Peru Bettolli, María Laura Revisiting wintertime cold air intrusions at the east of the Andes: Propagating features from subtropical Argentina to Peruvian Amazon and relationship with large-scale circulation patterns
topic_facet	Argentina Bolivian Amazon Circulation patterns Cold surges Low-level winds Peruvian Amazon Self-organizing maps air temperature atmospheric circulation atmospheric dynamics cold air spatiotemporal analysis troposphere winter Amazonia Andes Argentina Bolivia La Plata Basin Peru
description	This study investigates the spatial and temporal characteristics of cold surges that propagates northward along the eastern flank of the Andes from subtropical to tropical South America analysing wintertime in situ daily minimum temperature observations from Argentina, Bolivia and Peru and ERA-40 reanalysis over the 1975-2001 period. Cold surges usually last 2 or 3 days but are generally less persistent in the southern La Plata basin compared to tropical regions. On average, three to four cold surges are reported each year. Our analysis reveals that 52 % of cold episodes registered in the south of La Plata basin propagate northward to the northern Peruvian Amazon at a speed of around 20 m s-1. In comparison to cold surges that do not reach the tropical region, we demonstrate that these cold surges are characterized, before they reach the tropical region, by a higher occurrence of a specific circulation pattern associated to southern low-level winds progression toward low latitudes combined with subsidence and dry condition in the middle and low troposphere that reinforce the cold episode through a radiative effect. Finally, the relationship between cold surges and atmosphere dynamics is illustrated for the two most severe cold intrusions that reached the Peruvian and Bolivian Amazon in the last 20 years. © 2012 Springer-Verlag Berlin Heidelberg.
author	Bettolli, María Laura
author_facet	Bettolli, María Laura
author_sort	Bettolli, María Laura
title	Revisiting wintertime cold air intrusions at the east of the Andes: Propagating features from subtropical Argentina to Peruvian Amazon and relationship with large-scale circulation patterns
title_short	Revisiting wintertime cold air intrusions at the east of the Andes: Propagating features from subtropical Argentina to Peruvian Amazon and relationship with large-scale circulation patterns
title_full	Revisiting wintertime cold air intrusions at the east of the Andes: Propagating features from subtropical Argentina to Peruvian Amazon and relationship with large-scale circulation patterns
title_fullStr	Revisiting wintertime cold air intrusions at the east of the Andes: Propagating features from subtropical Argentina to Peruvian Amazon and relationship with large-scale circulation patterns
title_full_unstemmed	Revisiting wintertime cold air intrusions at the east of the Andes: Propagating features from subtropical Argentina to Peruvian Amazon and relationship with large-scale circulation patterns
title_sort	revisiting wintertime cold air intrusions at the east of the andes: propagating features from subtropical argentina to peruvian amazon and relationship with large-scale circulation patterns
publishDate	2013
url	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_09307575_v41_n7-8_p1983_Espinoza http://hdl.handle.net/20.500.12110/paper_09307575_v41_n7-8_p1983_Espinoza
work_keys_str_mv	AT bettollimarialaura revisitingwintertimecoldairintrusionsattheeastoftheandespropagatingfeaturesfromsubtropicalargentinatoperuvianamazonandrelationshipwithlargescalecirculationpatterns
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Revisiting wintertime cold air intrusions at the east of the Andes: Propagating features from subtropical Argentina to Peruvian Amazon and relationship with large-scale circulation patterns

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