Late Quaternary Variations in the South American Monsoon System as Inferred by Speleothems—New Perspectives Using the SISAL Database
Here we present an overview of speleothem δ<sup>18</sup>O records from South America, most of which are available in the Speleothem Isotopes Synthesis and Analysis (SISAL_v1) database. South American tropical and subtropical speleothem δ<sup>18</sup>O time s...
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doaj-197535307e744defb0fee7e1c7e0cfc82020-11-25T00:19:01ZengMDPI AGQuaternary2571-550X2019-01-0121610.3390/quat2010006quat2010006Late Quaternary Variations in the South American Monsoon System as Inferred by Speleothems—New Perspectives Using the SISAL DatabaseMichael Deininger0Brittany Marie Ward1Valdir F. Novello2Francisco W. Cruz3Institute of Geosciences, Johannes Gutenberg University Mainz, J.-J.-Becher-Weg 21, 55128 Mainz, GermanyFaculty of Science and Engineering, The University of Waikato, Private Bag 3105, Hamilton 3240, New ZealandInstitute of Geosciences, University of São Paulo, Rua do Lago 562, São Paulo 05508-080, BrazilInstitute of Geosciences, University of São Paulo, Rua do Lago 562, São Paulo 05508-080, BrazilHere we present an overview of speleothem δ<sup>18</sup>O records from South America, most of which are available in the Speleothem Isotopes Synthesis and Analysis (SISAL_v1) database. South American tropical and subtropical speleothem δ<sup>18</sup>O time series are primarily interpreted to reflect changes in precipitation amount, the amount effect, and consequently history of convection intensity variability of convergence zones such as the Intertropical Convergence Zone (ITCZ) and the South America Monsoon System (SAMS). We investigate past hydroclimate scenarios in South America related to the South American Monsoon System in three different time periods: Late Pleistocene, Holocene, and the last two millennia. Precession driven summertime insolation is the main driver of convective variability over the continent during the last 120 kyrs (from present day to 120 kyrs BP), including the Holocene. However, there is a dipole between speleothem δ<sup>18</sup>O records from western and eastern South America. Records located in the central region of Brazil are weakly affected by insolation-driven variability, and instead are more susceptible to the variability associated with the South Atlantic Convergence Zone (SACZ). Cold episodic events in the Northern Hemisphere, such as Heinrich and Bond Events, and the Little Ice Age, increase the convective activity of the SAMS, resulting in increased precipitation amount in South America.https://www.mdpi.com/2571-550X/2/1/6South American Monsoon SystemSAMSSISALspeleothemsquaternary |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Michael Deininger Brittany Marie Ward Valdir F. Novello Francisco W. Cruz |
spellingShingle |
Michael Deininger Brittany Marie Ward Valdir F. Novello Francisco W. Cruz Late Quaternary Variations in the South American Monsoon System as Inferred by Speleothems—New Perspectives Using the SISAL Database Quaternary South American Monsoon System SAMS SISAL speleothems quaternary |
author_facet |
Michael Deininger Brittany Marie Ward Valdir F. Novello Francisco W. Cruz |
author_sort |
Michael Deininger |
title |
Late Quaternary Variations in the South American Monsoon System as Inferred by Speleothems—New Perspectives Using the SISAL Database |
title_short |
Late Quaternary Variations in the South American Monsoon System as Inferred by Speleothems—New Perspectives Using the SISAL Database |
title_full |
Late Quaternary Variations in the South American Monsoon System as Inferred by Speleothems—New Perspectives Using the SISAL Database |
title_fullStr |
Late Quaternary Variations in the South American Monsoon System as Inferred by Speleothems—New Perspectives Using the SISAL Database |
title_full_unstemmed |
Late Quaternary Variations in the South American Monsoon System as Inferred by Speleothems—New Perspectives Using the SISAL Database |
title_sort |
late quaternary variations in the south american monsoon system as inferred by speleothems—new perspectives using the sisal database |
publisher |
MDPI AG |
series |
Quaternary |
issn |
2571-550X |
publishDate |
2019-01-01 |
description |
Here we present an overview of speleothem δ<sup>18</sup>O records from South America, most of which are available in the Speleothem Isotopes Synthesis and Analysis (SISAL_v1) database. South American tropical and subtropical speleothem δ<sup>18</sup>O time series are primarily interpreted to reflect changes in precipitation amount, the amount effect, and consequently history of convection intensity variability of convergence zones such as the Intertropical Convergence Zone (ITCZ) and the South America Monsoon System (SAMS). We investigate past hydroclimate scenarios in South America related to the South American Monsoon System in three different time periods: Late Pleistocene, Holocene, and the last two millennia. Precession driven summertime insolation is the main driver of convective variability over the continent during the last 120 kyrs (from present day to 120 kyrs BP), including the Holocene. However, there is a dipole between speleothem δ<sup>18</sup>O records from western and eastern South America. Records located in the central region of Brazil are weakly affected by insolation-driven variability, and instead are more susceptible to the variability associated with the South Atlantic Convergence Zone (SACZ). Cold episodic events in the Northern Hemisphere, such as Heinrich and Bond Events, and the Little Ice Age, increase the convective activity of the SAMS, resulting in increased precipitation amount in South America. |
topic |
South American Monsoon System SAMS SISAL speleothems quaternary |
url |
https://www.mdpi.com/2571-550X/2/1/6 |
work_keys_str_mv |
AT michaeldeininger latequaternaryvariationsinthesouthamericanmonsoonsystemasinferredbyspeleothemsnewperspectivesusingthesisaldatabase AT brittanymarieward latequaternaryvariationsinthesouthamericanmonsoonsystemasinferredbyspeleothemsnewperspectivesusingthesisaldatabase AT valdirfnovello latequaternaryvariationsinthesouthamericanmonsoonsystemasinferredbyspeleothemsnewperspectivesusingthesisaldatabase AT franciscowcruz latequaternaryvariationsinthesouthamericanmonsoonsystemasinferredbyspeleothemsnewperspectivesusingthesisaldatabase |
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1725373905595531264 |