Late Holocene slowdown of the Indian Ocean Walker circulation

Changes in tropical zonal atmospheric (Walker) circulation induce shifts in rainfall patterns along with devastating floods and severe droughts that dramatically impact the lives of millions of people. Historical records and observations of the Walker circulation over the 20th century disagree on th...

Full description

Saved in:
Bibliographic Details
Published inNature communications Vol. 8; no. 1; pp. 1015 - 8
Main Authors Mohtadi, Mahyar, Prange, Matthias, Schefuß, Enno, Jennerjahn, Tim C.
Format Journal Article
LanguageEnglish
Published London Nature Publishing Group UK 18.10.2017
Nature Publishing Group
Nature Portfolio
Subjects
704/106/2738
704/106/413
704/106/694/1108
Atmospheric circulation
Climate change
Drought
Global warming
Greenhouse effect
Holocene
Humanities and Social Sciences
multidisciplinary
Ocean temperature
Rainfall
Science
Science (multidisciplinary)
Thermocline
Indian Ocean
Online AccessGet full text

Cover

More Information
Summary:Changes in tropical zonal atmospheric (Walker) circulation induce shifts in rainfall patterns along with devastating floods and severe droughts that dramatically impact the lives of millions of people. Historical records and observations of the Walker circulation over the 20th century disagree on the sign of change and therefore, longer climate records are necessary to better project tropical circulation changes in response to global warming. Here we examine proxies for thermocline depth and rainfall in the eastern tropical Indian Ocean during the globally colder Last Glacial Maximum (19–23 thousand years ago) and for the past 3000 years. We show that increased thermocline depth and rainfall indicate a stronger-than-today Walker circulation during the Last Glacial Maximum, which is supported by an ensemble of climate simulations. Our findings underscore the sensitivity of tropical circulation to temperature change and provide evidence for a further weakening of the Walker circulation in response to greenhouse warming. Debate exists on the sign of change in tropical atmospheric circulation during global warming. Here the authors show a weaker Walker cell over the Indian Ocean during the warmer late Holocene compared to the globally colder Last Glacial Maximum, implying a further slowdown of the Walker cell in response to warming.
Bibliography:ObjectType-Article-1
SourceType-Scholarly Journals-1
ObjectType-Feature-2
content type line 23
ISSN:2041-1723
2041-1723
DOI:10.1038/s41467-017-00855-3