title: Coherent changes of southeastern equatorial and northern African rainfall during the last deglaciation.
abstract: During the last deglaciation, wetter conditions developed abruptly ~14,700 years ago in southeastern equatorial and northern Africa and continued into the Holocene. Explaining the abrupt onset and hemispheric coherence of this early African Humid Period is challenging due to opposing seasonal insolation patterns. In this work, we use a transient simulation with a climate model that provides a mechanistic understanding of deglacial tropical African precipitation changes. Our results show that meltwater-induced reduction in the Atlantic meridional overturning circulation (AMOC) during the early deglaciation suppressed precipitation in both regions. Once the AMOC reestablished, wetter conditions developed north of the equator in response to high summer insolation and increasing greenhouse gas (GHG) concentrations, whereas wetter conditions south of the equator were a response primarily to the GHG increase.
authors.affiliation: Climate and Global Dynamics Division, National Center for Atmospheric Research, Boulder, CO 80307-3000, USA. ottobli@ucar.edu.
authors.forename: Bette L
authors.initials: BL
authors.lastname: Otto-Bliesner
authors.affiliation: Department of Earth, Environmental, and Planetary Sciences, Brown University, Providence, RI 02912, USA.
authors.forename: James M
authors.initials: JM
authors.lastname: Russell
authors.affiliation: College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR 97331, USA.
authors.forename: Peter U
authors.initials: PU
authors.lastname: Clark
authors.affiliation: Center for Climatic Research and Department of Atmospheric and Oceanic Sciences, University of Wisconsin-Madison, Madison, WI 53706, USA. Laboratory for Climate, Ocean and Atmosphere Studies, School of Physics, Peking University, Beijing 100871, P. R. China.
authors.forename: Zhengyu
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Department of Geosciences and Institute of the Environment, University of Arizona, Tucson, AZ 85721, USA.
authors.forename: Jonathan T
authors.initials: JT
authors.lastname: Overpeck
authors.affiliation: College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR 97331, USA. Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, CO 80309, USA.
authors.forename: Bronwen
authors.initials: B
authors.lastname: Konecky
authors.affiliation: Department of Earth and Environmental Sciences, Columbia University, New York, NY 10027, USA.
authors.forename: Peter
authors.initials: P
authors.lastname: deMenocal
authors.affiliation: Department of Earth, Ocean, and Atmospheric Science, Florida State University, Tallahassee, FL 32306, USA.
authors.forename: Sharon E
authors.initials: SE
authors.lastname: Nicholson
authors.affiliation: Center for Climatic Research and Department of Atmospheric and Oceanic Sciences, University of Wisconsin-Madison, Madison, WI 53706, USA.
authors.forename: Feng
authors.initials: F
authors.lastname: He
authors.affiliation: Laboratory for Climate, Ocean and Atmosphere Studies, School of Physics, Peking University, Beijing 100871, P. R. China.
authors.forename: Zhengyao
authors.initials: Z
authors.lastname: Lu
mesh_terms: D000352:Africa, Northern; D005615:Freezing; D057232:Global Warming; D017752:Greenhouse Effect; D046448:Ice Cover; D011891:Rain