Teleconnection patterns orographically induced in model results and from observational data in the austral winter of the Southern Hemisphere
Low frequency disturbances in the Southern Hemisphere are investigated through an observational study and numerical model experiments. The orography of the Andes and Antarctica in the Southern Hemisphere are the forcing of numerical experiments, submitted to zonal climatological austral winter condi...
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2000
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_08998418_v20_n10_p1191_Seluchi http://hdl.handle.net/20.500.12110/paper_08998418_v20_n10_p1191_Seluchi |
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paper:paper_08998418_v20_n10_p1191_Seluchi2023-06-08T15:49:35Z Teleconnection patterns orographically induced in model results and from observational data in the austral winter of the Southern Hemisphere EOF analyses Low frequency streamfunction Orographic forcing in a baroclinic model Southern Hemisphere teleconnection patterns atmospheric circulation topography wave train atmospheric circulation climate forcing jet stream orography Southern Hemisphere teleconnection Antarctica South America Low frequency disturbances in the Southern Hemisphere are investigated through an observational study and numerical model experiments. The orography of the Andes and Antarctica in the Southern Hemisphere are the forcing of numerical experiments, submitted to zonal climatological austral winter conditions. The large-scale pattern forced by the Andes orography shows a high level wavetrain from the southeast of the mountain to the South Atlantic and two jet streams at high levels. The Antarctic case presents a wavenumber three horizontal structure around the hemisphere and three regions of jet stream. Characteristics of this wavenumber three model results are discussed based on analysis of streamfunction, vorticity and temperature, and related to blocking regions in the Southern Hemisphere. Empirical orthogonal function analysis of the low frequency filtered streamfunction at 250 hPa also shows, for the austral winter season, a wavenumber three structure and a wavetrain over the South Pacific and the South Atlantic, similar to the Pacific South American Pattern (PSA). Parts of the low frequency teleconnection patterns are identified in both the observational data and the model results, supporting the influence of the orography on the Southern Hemisphere atmospheric circulation. Analyses of periods with extreme amplitudes of the eigenvectors also show the influence of tropical convection on the anomalies over South America. Copyright (C) 2000 Royal Meteorological Society. 2000 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_08998418_v20_n10_p1191_Seluchi http://hdl.handle.net/20.500.12110/paper_08998418_v20_n10_p1191_Seluchi |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
EOF analyses Low frequency streamfunction Orographic forcing in a baroclinic model Southern Hemisphere teleconnection patterns atmospheric circulation topography wave train atmospheric circulation climate forcing jet stream orography Southern Hemisphere teleconnection Antarctica South America |
| spellingShingle |
EOF analyses Low frequency streamfunction Orographic forcing in a baroclinic model Southern Hemisphere teleconnection patterns atmospheric circulation topography wave train atmospheric circulation climate forcing jet stream orography Southern Hemisphere teleconnection Antarctica South America Teleconnection patterns orographically induced in model results and from observational data in the austral winter of the Southern Hemisphere |
| topic_facet |
EOF analyses Low frequency streamfunction Orographic forcing in a baroclinic model Southern Hemisphere teleconnection patterns atmospheric circulation topography wave train atmospheric circulation climate forcing jet stream orography Southern Hemisphere teleconnection Antarctica South America |
| description |
Low frequency disturbances in the Southern Hemisphere are investigated through an observational study and numerical model experiments. The orography of the Andes and Antarctica in the Southern Hemisphere are the forcing of numerical experiments, submitted to zonal climatological austral winter conditions. The large-scale pattern forced by the Andes orography shows a high level wavetrain from the southeast of the mountain to the South Atlantic and two jet streams at high levels. The Antarctic case presents a wavenumber three horizontal structure around the hemisphere and three regions of jet stream. Characteristics of this wavenumber three model results are discussed based on analysis of streamfunction, vorticity and temperature, and related to blocking regions in the Southern Hemisphere. Empirical orthogonal function analysis of the low frequency filtered streamfunction at 250 hPa also shows, for the austral winter season, a wavenumber three structure and a wavetrain over the South Pacific and the South Atlantic, similar to the Pacific South American Pattern (PSA). Parts of the low frequency teleconnection patterns are identified in both the observational data and the model results, supporting the influence of the orography on the Southern Hemisphere atmospheric circulation. Analyses of periods with extreme amplitudes of the eigenvectors also show the influence of tropical convection on the anomalies over South America. Copyright (C) 2000 Royal Meteorological Society. |
| title |
Teleconnection patterns orographically induced in model results and from observational data in the austral winter of the Southern Hemisphere |
| title_short |
Teleconnection patterns orographically induced in model results and from observational data in the austral winter of the Southern Hemisphere |
| title_full |
Teleconnection patterns orographically induced in model results and from observational data in the austral winter of the Southern Hemisphere |
| title_fullStr |
Teleconnection patterns orographically induced in model results and from observational data in the austral winter of the Southern Hemisphere |
| title_full_unstemmed |
Teleconnection patterns orographically induced in model results and from observational data in the austral winter of the Southern Hemisphere |
| title_sort |
teleconnection patterns orographically induced in model results and from observational data in the austral winter of the southern hemisphere |
| publishDate |
2000 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_08998418_v20_n10_p1191_Seluchi http://hdl.handle.net/20.500.12110/paper_08998418_v20_n10_p1191_Seluchi |
| _version_ |
1768544556343623680 |