Intraseasonal variability of wintertime frontal activity and its relationship with precipitation anomalies in the vicinity of South America

The intraseasonal variability of the frontal activity and its connection with the variability of the atmospheric circulation and precipitation in the Southern Hemisphere is studied. The frontal activity is defined as the relative vorticity times the local temperature gradient. A band-pass filter was...

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Autores principales:	Blazquez, Josefina, Solman, Silvina Alicia
Publicado:	2016
Materias:	Frontal activity Intraseasonal variability Large scale circulation Precipitation Southern hemisphere anomaly atmospheric circulation atmospheric front precipitation (climatology) seasonal variation Southern Hemisphere winter Pacific Ocean Pacific Ocean (South) South America
Acceso en línea:	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_09307575_v46_n7-8_p2327_Blazquez http://hdl.handle.net/20.500.12110/paper_09307575_v46_n7-8_p2327_Blazquez
Aporte de:	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires

id	paper:paper_09307575_v46_n7-8_p2327_Blazquez
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spelling	paper:paper_09307575_v46_n7-8_p2327_Blazquez2023-06-08T15:52:46Z Intraseasonal variability of wintertime frontal activity and its relationship with precipitation anomalies in the vicinity of South America Blazquez, Josefina Solman, Silvina Alicia Frontal activity Intraseasonal variability Large scale circulation Precipitation Southern hemisphere anomaly atmospheric circulation atmospheric front precipitation (climatology) seasonal variation Southern Hemisphere winter Pacific Ocean Pacific Ocean (South) South America The intraseasonal variability of the frontal activity and its connection with the variability of the atmospheric circulation and precipitation in the Southern Hemisphere is studied. The frontal activity is defined as the relative vorticity times the local temperature gradient. A band-pass filter was applied to retain the intraseasonal timescales. An empirical orthogonal function analysis was applied to the filtered frontal activity anomalies. The two main modes show positive and negative centers located mainly over the southern Pacific Ocean and South American sector and are in quadrature with each other. A similar pattern was found when the main modes of intraseasonal variability of the 500 hPa geopotential height were projected on the frontal activity, suggesting that the variability of fronts are influenced by the variability of the large scale atmospheric circulation. Moreover, the precipitation anomalies projected on the main modes of both frontal activity and 500 hPa geopotential height show similar structures, especially over the southern Pacific Ocean and South America, which may indicate that the variability of fronts controls the variability of precipitation. The lagged regression of the time series of the frontal activity areallyaveraged over one of the centers of action against the frontal activity anomaly field shows at lags −8 and 8 a similar pattern, suggesting a period of around 17 days for each mode. Moreover, lagged regression between times series of frontal activity and precipitation anomalies reveals an opposite pattern between southeastern South America and southern Chile, being precipitation anomalies over these two regions anti-correlated due to the frontal activity. © Springer-Verlag Berlin Heidelberg 2015. Fil:Blázquez, J. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Solman, S.A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2016 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_09307575_v46_n7-8_p2327_Blazquez http://hdl.handle.net/20.500.12110/paper_09307575_v46_n7-8_p2327_Blazquez
institution	Universidad de Buenos Aires
institution_str	I-28
repository_str	R-134
collection	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic	Frontal activity Intraseasonal variability Large scale circulation Precipitation Southern hemisphere anomaly atmospheric circulation atmospheric front precipitation (climatology) seasonal variation Southern Hemisphere winter Pacific Ocean Pacific Ocean (South) South America
spellingShingle	Frontal activity Intraseasonal variability Large scale circulation Precipitation Southern hemisphere anomaly atmospheric circulation atmospheric front precipitation (climatology) seasonal variation Southern Hemisphere winter Pacific Ocean Pacific Ocean (South) South America Blazquez, Josefina Solman, Silvina Alicia Intraseasonal variability of wintertime frontal activity and its relationship with precipitation anomalies in the vicinity of South America
topic_facet	Frontal activity Intraseasonal variability Large scale circulation Precipitation Southern hemisphere anomaly atmospheric circulation atmospheric front precipitation (climatology) seasonal variation Southern Hemisphere winter Pacific Ocean Pacific Ocean (South) South America
description	The intraseasonal variability of the frontal activity and its connection with the variability of the atmospheric circulation and precipitation in the Southern Hemisphere is studied. The frontal activity is defined as the relative vorticity times the local temperature gradient. A band-pass filter was applied to retain the intraseasonal timescales. An empirical orthogonal function analysis was applied to the filtered frontal activity anomalies. The two main modes show positive and negative centers located mainly over the southern Pacific Ocean and South American sector and are in quadrature with each other. A similar pattern was found when the main modes of intraseasonal variability of the 500 hPa geopotential height were projected on the frontal activity, suggesting that the variability of fronts are influenced by the variability of the large scale atmospheric circulation. Moreover, the precipitation anomalies projected on the main modes of both frontal activity and 500 hPa geopotential height show similar structures, especially over the southern Pacific Ocean and South America, which may indicate that the variability of fronts controls the variability of precipitation. The lagged regression of the time series of the frontal activity areallyaveraged over one of the centers of action against the frontal activity anomaly field shows at lags −8 and 8 a similar pattern, suggesting a period of around 17 days for each mode. Moreover, lagged regression between times series of frontal activity and precipitation anomalies reveals an opposite pattern between southeastern South America and southern Chile, being precipitation anomalies over these two regions anti-correlated due to the frontal activity. © Springer-Verlag Berlin Heidelberg 2015.
author	Blazquez, Josefina Solman, Silvina Alicia
author_facet	Blazquez, Josefina Solman, Silvina Alicia
author_sort	Blazquez, Josefina
title	Intraseasonal variability of wintertime frontal activity and its relationship with precipitation anomalies in the vicinity of South America
title_short	Intraseasonal variability of wintertime frontal activity and its relationship with precipitation anomalies in the vicinity of South America
title_full	Intraseasonal variability of wintertime frontal activity and its relationship with precipitation anomalies in the vicinity of South America
title_fullStr	Intraseasonal variability of wintertime frontal activity and its relationship with precipitation anomalies in the vicinity of South America
title_full_unstemmed	Intraseasonal variability of wintertime frontal activity and its relationship with precipitation anomalies in the vicinity of South America
title_sort	intraseasonal variability of wintertime frontal activity and its relationship with precipitation anomalies in the vicinity of south america
publishDate	2016
url	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_09307575_v46_n7-8_p2327_Blazquez http://hdl.handle.net/20.500.12110/paper_09307575_v46_n7-8_p2327_Blazquez
work_keys_str_mv	AT blazquezjosefina intraseasonalvariabilityofwintertimefrontalactivityanditsrelationshipwithprecipitationanomaliesinthevicinityofsouthamerica AT solmansilvinaalicia intraseasonalvariabilityofwintertimefrontalactivityanditsrelationshipwithprecipitationanomaliesinthevicinityofsouthamerica
_version_	1768542604089098240

Intraseasonal variability of wintertime frontal activity and its relationship with precipitation anomalies in the vicinity of South America

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