Millennial and orbital scale variability of the South American Monsoon during the penultimate glacial period

Stephen J. Burns, Lisa Kanner Welsh, Nick Scroxton, Hai Cheng, R. Lawrence Edwards

Research output: Contribution to journalArticle

3 Scopus citations

Abstract

The presence of large, rapid climate oscillations is the most prominent feature of the Earth’s last glacial period. These oscillations are observed throughout the Northern Hemisphere and into the Southern Hemisphere tropics. Whether similar oscillations are typical of prior glacial periods, however, has not been well established. Here, we present results of a study of the South American Summer Monsoon system that covers nearly the entire penultimate glacial period, from 195 to 135 ky BP. We use a well-dated, high-resolution (~50 y) time series of oxygen isotopes to show that the precession of the earth’s orbit is the primary control on monsoon intensity. After removing the precession signal we observe millennial oscillations that are very similar in amplitude and structure to the Dansgaard/Oeschger cycles of the last interglacial and that match well a synthetic reconstruction of millennial variability. Time series analyses shows that the most prominent of the observed cycles occur at considerably longer frequency (~3500 y) that the Dansgaard/Oeschger cycles from Marine Isotope Stages 2–4.

Original languageEnglish (US)
Article number1234
JournalScientific reports
Volume9
Issue number1
DOIs
StatePublished - Dec 1 2019

PubMed: MeSH publication types

  • Journal Article

Fingerprint Dive into the research topics of 'Millennial and orbital scale variability of the South American Monsoon during the penultimate glacial period'. Together they form a unique fingerprint.

  • Cite this