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.
Mohtadi M., Prange M., Schefuß E. and Jennerjahn T.C. (2017) Late Holocene slowdown of the Indian Ocean Walker circulation. Nature Communications 8(1): 1015. 10.1038/s41467-017-00855-3
@article{Mohtadi2017,
Title = {Late Holocene slowdown of the Indian Ocean Walker circulation},
Author = {Mohtadi, Mahyar and Prange, Matthias and Schefuß, Enno and Jennerjahn, Tim C.},
Editor = {},
Journal = {Nature Communications},
Year = {2017},
Pages = {1015},
Volume = {8},
Doi = {10.1038/s41467-017-00855-3},
Abstract = {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.},
}
TY - JOUR
AU - Mohtadi, Mahyar
AU - Prange, Matthias
AU - Schefuß, Enno
AU - Jennerjahn, Tim C.
TI - Late Holocene slowdown of the Indian Ocean Walker circulation
T2 - Nature Communications
PY - 2017
SP - 1015
VL - 8
DO - 10.1038/s41467-017-00855-3
AB - 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.
ER -
