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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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_09307575_v48_n7-8_p2569_Blazquez http://hdl.handle.net/20.500.12110/paper_09307575_v48_n7-8_p2569_Blazquez |
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paper:paper_09307575_v48_n7-8_p2569_Blazquez2023-06-08T15:52:47Z Interannual variability of the frontal activity in the Southern Hemisphere: relationship with atmospheric circulation and precipitation over southern South America Blazquez, Josefina Solman, Silvina Alicia 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. 2017 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_09307575_v48_n7-8_p2569_Blazquez 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 Blazquez, Josefina Solman, Silvina Alicia 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. |
| author |
Blazquez, Josefina Solman, Silvina Alicia |
| author_facet |
Blazquez, Josefina Solman, Silvina Alicia |
| author_sort |
Blazquez, Josefina |
| 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 |
| publishDate |
2017 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_09307575_v48_n7-8_p2569_Blazquez http://hdl.handle.net/20.500.12110/paper_09307575_v48_n7-8_p2569_Blazquez |
| work_keys_str_mv |
AT blazquezjosefina interannualvariabilityofthefrontalactivityinthesouthernhemisphererelationshipwithatmosphericcirculationandprecipitationoversouthernsouthamerica AT solmansilvinaalicia interannualvariabilityofthefrontalactivityinthesouthernhemisphererelationshipwithatmosphericcirculationandprecipitationoversouthernsouthamerica |
| _version_ |
1768541902255161344 |