Title
Mid-Holocene mean climate in the south eastern Pacific and its influence on South America
Date Issued
06 March 2012
Access level
metadata only access
Resource Type
journal article
Author(s)
Azzoug M.
Bentaleb I.
Chase B.M.
Fontugne M.
Jackson D.
Ledru M.P.
Maldonado A.
Sachs J.P.
Schauer A.J.
Publisher(s)
Elsevier
Abstract
The eastern tropical Pacific plays a key role in the tropical atmospheric circulation and in the global carbon cycle, and assessing the sensitivity of this region to global climate changes is a major challenge facing climatologists. Provided here is a synthesis of proxy records of the mean climate of the mid-Holocene (5-8. ka) along the south eastern Pacific margin and four regions of South America. These regions were selected for the strength and stability of ENSO teleconnections, and located outside the direct influence of the intertropical convergence zone or the southern westerlies in order to avoid the overprinting signal of their insolation-related variations and focus on the relationship between the eastern tropical Pacific and South America. This study is based on a review of published multiproxy data as well as new isotopic data from the Peruvian and Chilean coast. The available evidence indicates that sea-surface temperatures were ∼1-4 °C cooler from the Galapagos to the southern Peruvian coast as a result of increased coastal upwelling forced by changes in longshore windfields. The mean La Niña-like conditions in the eastern South Pacific were associated to aridity in southern Brazil and along the whole South American Pacific coast from central Chile to the Galapagos, and to wetter conditions on the western central Andes. This regional synthesis provides a coherent picture of the South American mean climate that is very similar to the modern precipitation pattern observed during La Niña conditions, suggesting that atmospheric teleconnections linking the South Eastern Pacific to these continental areas were similar in the middle Holocene. © 2011 Elsevier Ltd and INQUA.
Start page
55
End page
66
Volume
253
Language
English
OCDE Knowledge area
Meteorología y ciencias atmosféricas
Scopus EID
2-s2.0-84856558647
Source
Quaternary International
ISSN of the container
10406182
Sponsor(s)
This material is based upon work supported by the Pérou-Sud project, the National Geographic Society under grant # 8122-06 , the Joint Institute for the Study of Atmosphere and Ocean through a postdoctoral fellowship, the U.S. National Science Foundation under Grant No. NSF-ATM-0811382 , the U.S. National Oceanic and Atmospheric Administration under Grant No. NOAA-NA08OAR4310685 , and the FONDECYT under grants # 11070016 and # 1080458 . We are thankful to Danièle Lavallée, Michèle Julien, Fernanda Falabella, Orest E. Kawka. Thanks to Fredy Cardenas from IMARPE for providing oceanographic data. We are thankful to René Garreaud and two anonymous reviewers for helping improve the manuscript. This is the ISEM contribution 2011-017.
Sources of information:
Directorio de Producción Científica
Scopus