Interannual variability of the frontal activity in the Southern Hemisphere: relationship with atmospheric circulation and precipitation over southern South America

The interannual variability of the frontal activity over the western Southern Hemisphere and its linkage with the variability of the atmospheric circulation and precipitation over southern South America is studied. The analysis is focused on the austral winter and spring seasons. The frontal activit...

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Autores principales: Blázquez, J., Solman, S.A.
Formato: JOUR
Materias:
Atmospheric circulation
Frontal activity
Interannual variability
Precipitation
Southern Hemisphere
annual variation
atmospheric circulation
El Nino-Southern Oscillation
precipitation (climatology)
spring (season)
winter
Brazil
Chile
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_09307575_v48_n7-8_p2569_Blazquez
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id todo:paper_09307575_v48_n7-8_p2569_Blazquez
record_format dspace
spelling todo:paper_09307575_v48_n7-8_p2569_Blazquez2023-10-03T15:48:03Z Interannual variability of the frontal activity in the Southern Hemisphere: relationship with atmospheric circulation and precipitation over southern South America Blázquez, J. Solman, S.A. Atmospheric circulation Frontal activity Interannual variability Precipitation Southern Hemisphere annual variation atmospheric circulation El Nino-Southern Oscillation precipitation (climatology) Southern Hemisphere spring (season) winter Brazil Chile The interannual variability of the frontal activity over the western Southern Hemisphere and its linkage with the variability of the atmospheric circulation and precipitation over southern South America is studied. The analysis is focused on the austral winter and spring seasons. The frontal activity is represented by an index defined as the product between the horizontal gradient of temperature and the relative vorticity at 850 hPa (FI) and is computed from the ERA Interim and NCEP2 reanalysis. For the two seasons the main mode of variability of FI, as depicted by the first Empirical Orthogonal Function, presents centres of action located in the southern part of the western Southern Hemisphere. This pattern is present in the two reanalysis datasets. The correlation coefficients between the principal component of the leading mode of FI and the two main modes of the 500 hPa geopotential height indicate that both the ENSO-mode and the SAM modulate the leading pattern of FI in winter while during the spring season the ENSO-mode controls the FI variability. The variability of the FI has a robust influence on the interannual variability of precipitation over southern South America and adjacent oceans. Over the continent, it was found that the pattern of precipitation anomalies associated with the variability of the FI depicts significant signals over southeastern South America (SESA), centre and south of Chile for winter and over SESA and southeastern Brazil for spring and agrees with the pattern of the leading mode of precipitation variability over southern South America. © 2016, Springer-Verlag Berlin Heidelberg. 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. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_09307575_v48_n7-8_p2569_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 Atmospheric circulation
Frontal activity
Interannual variability
Precipitation
Southern Hemisphere
annual variation
atmospheric circulation
El Nino-Southern Oscillation
precipitation (climatology)
Southern Hemisphere
spring (season)
winter
Brazil
Chile
spellingShingle Atmospheric circulation
Frontal activity
Interannual variability
Precipitation
Southern Hemisphere
annual variation
atmospheric circulation
El Nino-Southern Oscillation
precipitation (climatology)
Southern Hemisphere
spring (season)
winter
Brazil
Chile
Blázquez, J.
Solman, S.A.
Interannual variability of the frontal activity in the Southern Hemisphere: relationship with atmospheric circulation and precipitation over southern South America
topic_facet Atmospheric circulation
Frontal activity
Interannual variability
Precipitation
Southern Hemisphere
annual variation
atmospheric circulation
El Nino-Southern Oscillation
precipitation (climatology)
Southern Hemisphere
spring (season)
winter
Brazil
Chile
description The interannual variability of the frontal activity over the western Southern Hemisphere and its linkage with the variability of the atmospheric circulation and precipitation over southern South America is studied. The analysis is focused on the austral winter and spring seasons. The frontal activity is represented by an index defined as the product between the horizontal gradient of temperature and the relative vorticity at 850 hPa (FI) and is computed from the ERA Interim and NCEP2 reanalysis. For the two seasons the main mode of variability of FI, as depicted by the first Empirical Orthogonal Function, presents centres of action located in the southern part of the western Southern Hemisphere. This pattern is present in the two reanalysis datasets. The correlation coefficients between the principal component of the leading mode of FI and the two main modes of the 500 hPa geopotential height indicate that both the ENSO-mode and the SAM modulate the leading pattern of FI in winter while during the spring season the ENSO-mode controls the FI variability. The variability of the FI has a robust influence on the interannual variability of precipitation over southern South America and adjacent oceans. Over the continent, it was found that the pattern of precipitation anomalies associated with the variability of the FI depicts significant signals over southeastern South America (SESA), centre and south of Chile for winter and over SESA and southeastern Brazil for spring and agrees with the pattern of the leading mode of precipitation variability over southern South America. © 2016, Springer-Verlag Berlin Heidelberg.
format JOUR
author Blázquez, J.
Solman, S.A.
author_facet Blázquez, J.
Solman, S.A.
author_sort Blázquez, J.
title Interannual variability of the frontal activity in the Southern Hemisphere: relationship with atmospheric circulation and precipitation over southern South America
title_short Interannual variability of the frontal activity in the Southern Hemisphere: relationship with atmospheric circulation and precipitation over southern South America
title_full Interannual variability of the frontal activity in the Southern Hemisphere: relationship with atmospheric circulation and precipitation over southern South America
title_fullStr Interannual variability of the frontal activity in the Southern Hemisphere: relationship with atmospheric circulation and precipitation over southern South America
title_full_unstemmed Interannual variability of the frontal activity in the Southern Hemisphere: relationship with atmospheric circulation and precipitation over southern South America
title_sort interannual variability of the frontal activity in the southern hemisphere: relationship with atmospheric circulation and precipitation over southern south america
url http://hdl.handle.net/20.500.12110/paper_09307575_v48_n7-8_p2569_Blazquez
work_keys_str_mv AT blazquezj interannualvariabilityofthefrontalactivityinthesouthernhemisphererelationshipwithatmosphericcirculationandprecipitationoversouthernsouthamerica
AT solmansa interannualvariabilityofthefrontalactivityinthesouthernhemisphererelationshipwithatmosphericcirculationandprecipitationoversouthernsouthamerica
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