A multi-proxy record of climatic changes and Southern Westerlies dynamics in the subtropical Andes of South America since 12ka

Autores
Maldonado Castro, Antonio Javier; de Porras, Maria Eugenia; Maidana, Nora Irene; Massaferro, Julieta; Negrini, Robert; Antinao, José luis; Tiner, Rachel
Año de publicación
2019
Idioma
inglés
Tipo de recurso
documento de conferencia
Estado
versión publicada
Descripción
The subtropical Andes of South America are a key area to study the interaction of tropical and extra-tropical climatic systems. The climate is characterized by wet winters and dry summers related to its position at the northern edge of the Southern Westerlies Wind Belt (SWWB) which migrate seasonally so that during the austral winter they expand equatorward to about 30°S. The SWWB is modulated by the presence of the Southern Eastern Pacific Subtropical Anticyclone (SEPSA) which migrates in conjunction with the SWWB determining the strong precipitation seasonality of Subtropical Andes. Thus, the interplay of the SWWB modulated by the SEPSA at millennial-centennial scale superimposed to the interannual scale variability related to the Southern Oscillation is reflected in precipitation patterns over the Andes allowing to trace the winter activity of SWWB at millennial-to-interannual time scales. The present paper presents the dynamics of the northern edge of the SWWB since 12ka based on a multi-proxy record of Laguna El Cepo located at 30°S (2900masl). The pollen record is dominated of Poaceae with maximum values between 12-11ka, 9.6-8ka and since 5.8ka onwards which suggest moderate humid conditions peaking since 2.2ka given the increase of Portulacaceae and Apiaceae. Dry phases characterized by increases of Ephedra occurred between 11-9.6ka and particularly 8-5.8ka. Pollen accumulation rates recorded the driest conditions between 11-5.8ka. The charcoal record shows that fire occurrence increased from 7ka onwards with maximum values between 7-6ka, during the driest period for the whole record.The diatom record reflects cold temperature of the water given the high values of Eunotia spp at 12-10.5ka and 4.8-3.8ka alternating with warm conditions between 10-8.5 and 8-6ka pointed out by Chamaeopinnularia sp which together with Chamaeopinnularia hassiatica reveal the warmest conditions around 6.4ka. High percentages of Kobayasiella micropundata between 8.5-8ka and at 5.5ka indicate the occurrence of exogenous input into the lake. High values of Eutonia spp during the late Holocene reflect cooler conditions during the last 5ka, compared to the early-mid Holocene conditions.The chironomid record show high percentages of Cricotopus suggesting littoral environment dominance at 12ka. Cold conditions associated to discrete increases of Smitia between 8.5-8ka and 5ka. The presence of Chironomus between 8-4.8ka and its highest percentages at 7.3-6.4ka suggest warm conditions. Sedimentological proxies suggest a recurrence of storms around 8.5-8ka and 5.8-4ka and a decrease productivity of the lake between 7.7-5.4ka.The joint interpretation of different proxy records suggests cold and humid conditions during the end of Pleistocene while the basin was still becoming a lake. During the early and mid-Holocene up to 5.8ka, dry and warm conditions dominated, with increased occurrence of storms around 8.5-8ka. The last 5.8ka appeared to be relatively more humid and colder conditions than the early and mid-Holocene.
Fil: Maldonado Castro, Antonio Javier. Comisión Nacional de Investigación Científica y Tecnológica. Centro de Investigación Regional. Centro de Estudios en Zonas Áridas; Chile
Fil: de Porras, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina
Fil: Maidana, Nora Irene. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina
Fil: Massaferro, Julieta. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Ministerio de Ambiente y Desarrollo Sustentable. Administración de Parques Nacionales. Parque Nacional "Nahuel Huapi". Departamento Conservación y Educación Ambiental.; Argentina
Fil: Negrini, Robert. California State University; Estados Unidos
Fil: Antinao, José luis. Indiana University; Estados Unidos. Desert Research Institute; Estados Unidos. Centro de Investigación para la Gestión Integrada de Riesgo de desastres; Chile
Fil: Tiner, Rachel. California State University; Estados Unidos
20th Congress of the International Union for Quaternary Research
Dublin
Irlanda
International Union for Quaternary Research
Materia
SUBTROPICAL ANDES
WESTERLIES
HIGH ANDEAN
HOLOCENE
Nivel de accesibilidad
acceso abierto
Condiciones de uso
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
Repositorio
CONICET Digital (CONICET)
Institución
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identificador
oai:ri.conicet.gov.ar:11336/237434

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network_acronym_str CONICETDig
repository_id_str 3498
network_name_str CONICET Digital (CONICET)
spelling A multi-proxy record of climatic changes and Southern Westerlies dynamics in the subtropical Andes of South America since 12kaMaldonado Castro, Antonio Javierde Porras, Maria EugeniaMaidana, Nora IreneMassaferro, JulietaNegrini, RobertAntinao, José luisTiner, RachelSUBTROPICAL ANDESWESTERLIESHIGH ANDEANHOLOCENEhttps://purl.org/becyt/ford/1.5https://purl.org/becyt/ford/1The subtropical Andes of South America are a key area to study the interaction of tropical and extra-tropical climatic systems. The climate is characterized by wet winters and dry summers related to its position at the northern edge of the Southern Westerlies Wind Belt (SWWB) which migrate seasonally so that during the austral winter they expand equatorward to about 30°S. The SWWB is modulated by the presence of the Southern Eastern Pacific Subtropical Anticyclone (SEPSA) which migrates in conjunction with the SWWB determining the strong precipitation seasonality of Subtropical Andes. Thus, the interplay of the SWWB modulated by the SEPSA at millennial-centennial scale superimposed to the interannual scale variability related to the Southern Oscillation is reflected in precipitation patterns over the Andes allowing to trace the winter activity of SWWB at millennial-to-interannual time scales. The present paper presents the dynamics of the northern edge of the SWWB since 12ka based on a multi-proxy record of Laguna El Cepo located at 30°S (2900masl). The pollen record is dominated of Poaceae with maximum values between 12-11ka, 9.6-8ka and since 5.8ka onwards which suggest moderate humid conditions peaking since 2.2ka given the increase of Portulacaceae and Apiaceae. Dry phases characterized by increases of Ephedra occurred between 11-9.6ka and particularly 8-5.8ka. Pollen accumulation rates recorded the driest conditions between 11-5.8ka. The charcoal record shows that fire occurrence increased from 7ka onwards with maximum values between 7-6ka, during the driest period for the whole record.The diatom record reflects cold temperature of the water given the high values of Eunotia spp at 12-10.5ka and 4.8-3.8ka alternating with warm conditions between 10-8.5 and 8-6ka pointed out by Chamaeopinnularia sp which together with Chamaeopinnularia hassiatica reveal the warmest conditions around 6.4ka. High percentages of Kobayasiella micropundata between 8.5-8ka and at 5.5ka indicate the occurrence of exogenous input into the lake. High values of Eutonia spp during the late Holocene reflect cooler conditions during the last 5ka, compared to the early-mid Holocene conditions.The chironomid record show high percentages of Cricotopus suggesting littoral environment dominance at 12ka. Cold conditions associated to discrete increases of Smitia between 8.5-8ka and 5ka. The presence of Chironomus between 8-4.8ka and its highest percentages at 7.3-6.4ka suggest warm conditions. Sedimentological proxies suggest a recurrence of storms around 8.5-8ka and 5.8-4ka and a decrease productivity of the lake between 7.7-5.4ka.The joint interpretation of different proxy records suggests cold and humid conditions during the end of Pleistocene while the basin was still becoming a lake. During the early and mid-Holocene up to 5.8ka, dry and warm conditions dominated, with increased occurrence of storms around 8.5-8ka. The last 5.8ka appeared to be relatively more humid and colder conditions than the early and mid-Holocene.Fil: Maldonado Castro, Antonio Javier. Comisión Nacional de Investigación Científica y Tecnológica. Centro de Investigación Regional. Centro de Estudios en Zonas Áridas; ChileFil: de Porras, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Maidana, Nora Irene. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Massaferro, Julieta. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Ministerio de Ambiente y Desarrollo Sustentable. Administración de Parques Nacionales. Parque Nacional "Nahuel Huapi". Departamento Conservación y Educación Ambiental.; ArgentinaFil: Negrini, Robert. California State University; Estados UnidosFil: Antinao, José luis. Indiana University; Estados Unidos. Desert Research Institute; Estados Unidos. Centro de Investigación para la Gestión Integrada de Riesgo de desastres; ChileFil: Tiner, Rachel. California State University; Estados Unidos20th Congress of the International Union for Quaternary ResearchDublinIrlandaInternational Union for Quaternary ResearchInternational Union for Quaternary Research2019info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/conferenceObjectCongresoBookhttp://purl.org/coar/resource_type/c_5794info:ar-repo/semantics/documentoDeConferenciaapplication/pdfapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/237434A multi-proxy record of climatic changes and Southern Westerlies dynamics in the subtropical Andes of South America since 12ka; 20th Congress of the International Union for Quaternary Research; Dublin; Irlanda; 2019; 2703-2703CONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/url/http://iqua.ie/wp-content/uploads/2020/02/INQUA-2019-Abstract-book.pdfInternacionalinfo:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-09-29T09:46:00Zoai:ri.conicet.gov.ar:11336/237434instacron:CONICETInstitucionalhttp://ri.conicet.gov.ar/Organismo científico-tecnológicoNo correspondehttp://ri.conicet.gov.ar/oai/requestdasensio@conicet.gov.ar; lcarlino@conicet.gov.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:34982025-09-29 09:46:00.531CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv A multi-proxy record of climatic changes and Southern Westerlies dynamics in the subtropical Andes of South America since 12ka
title A multi-proxy record of climatic changes and Southern Westerlies dynamics in the subtropical Andes of South America since 12ka
spellingShingle A multi-proxy record of climatic changes and Southern Westerlies dynamics in the subtropical Andes of South America since 12ka
Maldonado Castro, Antonio Javier
SUBTROPICAL ANDES
WESTERLIES
HIGH ANDEAN
HOLOCENE
title_short A multi-proxy record of climatic changes and Southern Westerlies dynamics in the subtropical Andes of South America since 12ka
title_full A multi-proxy record of climatic changes and Southern Westerlies dynamics in the subtropical Andes of South America since 12ka
title_fullStr A multi-proxy record of climatic changes and Southern Westerlies dynamics in the subtropical Andes of South America since 12ka
title_full_unstemmed A multi-proxy record of climatic changes and Southern Westerlies dynamics in the subtropical Andes of South America since 12ka
title_sort A multi-proxy record of climatic changes and Southern Westerlies dynamics in the subtropical Andes of South America since 12ka
dc.creator.none.fl_str_mv Maldonado Castro, Antonio Javier
de Porras, Maria Eugenia
Maidana, Nora Irene
Massaferro, Julieta
Negrini, Robert
Antinao, José luis
Tiner, Rachel
author Maldonado Castro, Antonio Javier
author_facet Maldonado Castro, Antonio Javier
de Porras, Maria Eugenia
Maidana, Nora Irene
Massaferro, Julieta
Negrini, Robert
Antinao, José luis
Tiner, Rachel
author_role author
author2 de Porras, Maria Eugenia
Maidana, Nora Irene
Massaferro, Julieta
Negrini, Robert
Antinao, José luis
Tiner, Rachel
author2_role author
author
author
author
author
author
dc.subject.none.fl_str_mv SUBTROPICAL ANDES
WESTERLIES
HIGH ANDEAN
HOLOCENE
topic SUBTROPICAL ANDES
WESTERLIES
HIGH ANDEAN
HOLOCENE
purl_subject.fl_str_mv https://purl.org/becyt/ford/1.5
https://purl.org/becyt/ford/1
dc.description.none.fl_txt_mv The subtropical Andes of South America are a key area to study the interaction of tropical and extra-tropical climatic systems. The climate is characterized by wet winters and dry summers related to its position at the northern edge of the Southern Westerlies Wind Belt (SWWB) which migrate seasonally so that during the austral winter they expand equatorward to about 30°S. The SWWB is modulated by the presence of the Southern Eastern Pacific Subtropical Anticyclone (SEPSA) which migrates in conjunction with the SWWB determining the strong precipitation seasonality of Subtropical Andes. Thus, the interplay of the SWWB modulated by the SEPSA at millennial-centennial scale superimposed to the interannual scale variability related to the Southern Oscillation is reflected in precipitation patterns over the Andes allowing to trace the winter activity of SWWB at millennial-to-interannual time scales. The present paper presents the dynamics of the northern edge of the SWWB since 12ka based on a multi-proxy record of Laguna El Cepo located at 30°S (2900masl). The pollen record is dominated of Poaceae with maximum values between 12-11ka, 9.6-8ka and since 5.8ka onwards which suggest moderate humid conditions peaking since 2.2ka given the increase of Portulacaceae and Apiaceae. Dry phases characterized by increases of Ephedra occurred between 11-9.6ka and particularly 8-5.8ka. Pollen accumulation rates recorded the driest conditions between 11-5.8ka. The charcoal record shows that fire occurrence increased from 7ka onwards with maximum values between 7-6ka, during the driest period for the whole record.The diatom record reflects cold temperature of the water given the high values of Eunotia spp at 12-10.5ka and 4.8-3.8ka alternating with warm conditions between 10-8.5 and 8-6ka pointed out by Chamaeopinnularia sp which together with Chamaeopinnularia hassiatica reveal the warmest conditions around 6.4ka. High percentages of Kobayasiella micropundata between 8.5-8ka and at 5.5ka indicate the occurrence of exogenous input into the lake. High values of Eutonia spp during the late Holocene reflect cooler conditions during the last 5ka, compared to the early-mid Holocene conditions.The chironomid record show high percentages of Cricotopus suggesting littoral environment dominance at 12ka. Cold conditions associated to discrete increases of Smitia between 8.5-8ka and 5ka. The presence of Chironomus between 8-4.8ka and its highest percentages at 7.3-6.4ka suggest warm conditions. Sedimentological proxies suggest a recurrence of storms around 8.5-8ka and 5.8-4ka and a decrease productivity of the lake between 7.7-5.4ka.The joint interpretation of different proxy records suggests cold and humid conditions during the end of Pleistocene while the basin was still becoming a lake. During the early and mid-Holocene up to 5.8ka, dry and warm conditions dominated, with increased occurrence of storms around 8.5-8ka. The last 5.8ka appeared to be relatively more humid and colder conditions than the early and mid-Holocene.
Fil: Maldonado Castro, Antonio Javier. Comisión Nacional de Investigación Científica y Tecnológica. Centro de Investigación Regional. Centro de Estudios en Zonas Áridas; Chile
Fil: de Porras, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina
Fil: Maidana, Nora Irene. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina
Fil: Massaferro, Julieta. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Ministerio de Ambiente y Desarrollo Sustentable. Administración de Parques Nacionales. Parque Nacional "Nahuel Huapi". Departamento Conservación y Educación Ambiental.; Argentina
Fil: Negrini, Robert. California State University; Estados Unidos
Fil: Antinao, José luis. Indiana University; Estados Unidos. Desert Research Institute; Estados Unidos. Centro de Investigación para la Gestión Integrada de Riesgo de desastres; Chile
Fil: Tiner, Rachel. California State University; Estados Unidos
20th Congress of the International Union for Quaternary Research
Dublin
Irlanda
International Union for Quaternary Research
description The subtropical Andes of South America are a key area to study the interaction of tropical and extra-tropical climatic systems. The climate is characterized by wet winters and dry summers related to its position at the northern edge of the Southern Westerlies Wind Belt (SWWB) which migrate seasonally so that during the austral winter they expand equatorward to about 30°S. The SWWB is modulated by the presence of the Southern Eastern Pacific Subtropical Anticyclone (SEPSA) which migrates in conjunction with the SWWB determining the strong precipitation seasonality of Subtropical Andes. Thus, the interplay of the SWWB modulated by the SEPSA at millennial-centennial scale superimposed to the interannual scale variability related to the Southern Oscillation is reflected in precipitation patterns over the Andes allowing to trace the winter activity of SWWB at millennial-to-interannual time scales. The present paper presents the dynamics of the northern edge of the SWWB since 12ka based on a multi-proxy record of Laguna El Cepo located at 30°S (2900masl). The pollen record is dominated of Poaceae with maximum values between 12-11ka, 9.6-8ka and since 5.8ka onwards which suggest moderate humid conditions peaking since 2.2ka given the increase of Portulacaceae and Apiaceae. Dry phases characterized by increases of Ephedra occurred between 11-9.6ka and particularly 8-5.8ka. Pollen accumulation rates recorded the driest conditions between 11-5.8ka. The charcoal record shows that fire occurrence increased from 7ka onwards with maximum values between 7-6ka, during the driest period for the whole record.The diatom record reflects cold temperature of the water given the high values of Eunotia spp at 12-10.5ka and 4.8-3.8ka alternating with warm conditions between 10-8.5 and 8-6ka pointed out by Chamaeopinnularia sp which together with Chamaeopinnularia hassiatica reveal the warmest conditions around 6.4ka. High percentages of Kobayasiella micropundata between 8.5-8ka and at 5.5ka indicate the occurrence of exogenous input into the lake. High values of Eutonia spp during the late Holocene reflect cooler conditions during the last 5ka, compared to the early-mid Holocene conditions.The chironomid record show high percentages of Cricotopus suggesting littoral environment dominance at 12ka. Cold conditions associated to discrete increases of Smitia between 8.5-8ka and 5ka. The presence of Chironomus between 8-4.8ka and its highest percentages at 7.3-6.4ka suggest warm conditions. Sedimentological proxies suggest a recurrence of storms around 8.5-8ka and 5.8-4ka and a decrease productivity of the lake between 7.7-5.4ka.The joint interpretation of different proxy records suggests cold and humid conditions during the end of Pleistocene while the basin was still becoming a lake. During the early and mid-Holocene up to 5.8ka, dry and warm conditions dominated, with increased occurrence of storms around 8.5-8ka. The last 5.8ka appeared to be relatively more humid and colder conditions than the early and mid-Holocene.
publishDate 2019
dc.date.none.fl_str_mv 2019
dc.type.none.fl_str_mv info:eu-repo/semantics/publishedVersion
info:eu-repo/semantics/conferenceObject
Congreso
Book
http://purl.org/coar/resource_type/c_5794
info:ar-repo/semantics/documentoDeConferencia
status_str publishedVersion
format conferenceObject
dc.identifier.none.fl_str_mv http://hdl.handle.net/11336/237434
A multi-proxy record of climatic changes and Southern Westerlies dynamics in the subtropical Andes of South America since 12ka; 20th Congress of the International Union for Quaternary Research; Dublin; Irlanda; 2019; 2703-2703
CONICET Digital
CONICET
url http://hdl.handle.net/11336/237434
identifier_str_mv A multi-proxy record of climatic changes and Southern Westerlies dynamics in the subtropical Andes of South America since 12ka; 20th Congress of the International Union for Quaternary Research; Dublin; Irlanda; 2019; 2703-2703
CONICET Digital
CONICET
dc.language.none.fl_str_mv eng
language eng
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https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
eu_rights_str_mv openAccess
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dc.coverage.none.fl_str_mv Internacional
dc.publisher.none.fl_str_mv International Union for Quaternary Research
publisher.none.fl_str_mv International Union for Quaternary Research
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