Links between topography, moisture fluxes pathways and precipitation over South America

The Andes Cordillera plays a role in driving moisture and heat from tropical onto subtropical South America. It forces the development of a lee-side trough that covers most of western Argentina and a low-level jet that maximizes over Paraguay, eastern Bolivia and northern Argentina and is tightly li...

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Autores principales: Saurral, R.I., Camilloni, I.A., Ambrizzi, T.
Formato: JOUR
Materias:
Andes Cordillera
Global climate models
Precipitation
South American climate
atmospheric moisture
climate modeling
global climate
precipitation (climatology)
precipitation assessment
rainfall
topography
Andes
Argentina
Bolivia
Paraguay
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_09307575_v45_n3-4_p777_Saurral
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id todo:paper_09307575_v45_n3-4_p777_Saurral
record_format dspace
spelling todo:paper_09307575_v45_n3-4_p777_Saurral2023-10-03T15:48:00Z Links between topography, moisture fluxes pathways and precipitation over South America Saurral, R.I. Camilloni, I.A. Ambrizzi, T. Andes Cordillera Global climate models Precipitation South American climate atmospheric moisture climate modeling global climate precipitation (climatology) precipitation assessment rainfall topography Andes Argentina Bolivia Paraguay The Andes Cordillera plays a role in driving moisture and heat from tropical onto subtropical South America. It forces the development of a lee-side trough that covers most of western Argentina and a low-level jet that maximizes over Paraguay, eastern Bolivia and northern Argentina and is tightly linked to precipitation variability over much of central and southeastern South America. Its steep slopes and the large zonal gradients in topography between the Equator and 40°S are misrepresented in climate simulations using Global Climate Models (GCM) with resolutions coarser than about 100 km, since they naturally have a poor representation of the Andes and related circulation features. This paper analyses the impact of varying artificially the altitude of the Andes Cordillera in a GCM as well as increasing the horizontal resolution to study how these variations determine moisture fluxes and precipitation over selected regions of South America. Results show that the height of the Andes is crucial in shaping moisture fluxes pathways onto subtropical South America all year long. In particular, the low-level jet is only simulated when the Andes heights are doubled. At the same time, the relationship between the Andes shape and the location of the Bolivian High in summer is also discussed. In terms of precipitation, the lowest bias in the simulations is achieved when the horizontal resolution is increased, while in particular near the Andes foothills the simulated annual rainfall is largely determined by the Mountains shape. © 2014, Springer-Verlag Berlin Heidelberg. Fil:Saurral, R.I. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Camilloni, I.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_v45_n3-4_p777_Saurral
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Andes Cordillera
Global climate models
Precipitation
South American climate
atmospheric moisture
climate modeling
global climate
precipitation (climatology)
precipitation assessment
rainfall
topography
Andes
Argentina
Bolivia
Paraguay
spellingShingle Andes Cordillera
Global climate models
Precipitation
South American climate
atmospheric moisture
climate modeling
global climate
precipitation (climatology)
precipitation assessment
rainfall
topography
Andes
Argentina
Bolivia
Paraguay
Saurral, R.I.
Camilloni, I.A.
Ambrizzi, T.
Links between topography, moisture fluxes pathways and precipitation over South America
topic_facet Andes Cordillera
Global climate models
Precipitation
South American climate
atmospheric moisture
climate modeling
global climate
precipitation (climatology)
precipitation assessment
rainfall
topography
Andes
Argentina
Bolivia
Paraguay
description The Andes Cordillera plays a role in driving moisture and heat from tropical onto subtropical South America. It forces the development of a lee-side trough that covers most of western Argentina and a low-level jet that maximizes over Paraguay, eastern Bolivia and northern Argentina and is tightly linked to precipitation variability over much of central and southeastern South America. Its steep slopes and the large zonal gradients in topography between the Equator and 40°S are misrepresented in climate simulations using Global Climate Models (GCM) with resolutions coarser than about 100 km, since they naturally have a poor representation of the Andes and related circulation features. This paper analyses the impact of varying artificially the altitude of the Andes Cordillera in a GCM as well as increasing the horizontal resolution to study how these variations determine moisture fluxes and precipitation over selected regions of South America. Results show that the height of the Andes is crucial in shaping moisture fluxes pathways onto subtropical South America all year long. In particular, the low-level jet is only simulated when the Andes heights are doubled. At the same time, the relationship between the Andes shape and the location of the Bolivian High in summer is also discussed. In terms of precipitation, the lowest bias in the simulations is achieved when the horizontal resolution is increased, while in particular near the Andes foothills the simulated annual rainfall is largely determined by the Mountains shape. © 2014, Springer-Verlag Berlin Heidelberg.
format JOUR
author Saurral, R.I.
Camilloni, I.A.
Ambrizzi, T.
author_facet Saurral, R.I.
Camilloni, I.A.
Ambrizzi, T.
author_sort Saurral, R.I.
title Links between topography, moisture fluxes pathways and precipitation over South America
title_short Links between topography, moisture fluxes pathways and precipitation over South America
title_full Links between topography, moisture fluxes pathways and precipitation over South America
title_fullStr Links between topography, moisture fluxes pathways and precipitation over South America
title_full_unstemmed Links between topography, moisture fluxes pathways and precipitation over South America
title_sort links between topography, moisture fluxes pathways and precipitation over south america
url http://hdl.handle.net/20.500.12110/paper_09307575_v45_n3-4_p777_Saurral
work_keys_str_mv AT saurralri linksbetweentopographymoisturefluxespathwaysandprecipitationoversouthamerica
AT camilloniia linksbetweentopographymoisturefluxespathwaysandprecipitationoversouthamerica
AT ambrizzit linksbetweentopographymoisturefluxespathwaysandprecipitationoversouthamerica
_version_ 1782023981705986048

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