Greening of the Sahara suppressed ENSO activity during the mid-Holocene

• DOI: 10.1038/ncomms16020
• Publication Date: 2017-07-07T09:13:57Z
• Authors: Francesco S. R. P...; Qiong Zhang; Francesco Muschit...; Zhengyao Lu; Léon Chafik; Eva M. Niedermeyer; J. Curt Stager; Kim M. Cobb; Zhengyu Liu
• Keywords: Orbital forcing; Paleoclimatology; Forcing (mathematics); Walker circulation; Multivariate ENSO index; Climate state

Abstract The evolution of the El Niño-Southern Oscillation (ENSO) during Holocene remains uncertain. In particular, a host new paleoclimate records suggest that ENSO internal variability or other external forcings may have dwarfed fairly modest response to precessional insolation changes simulated in climate models. Here, using fully coupled ocean-atmosphere model simulations, we show accounting for vegetated and less dusty Sahara mid-Holocene relative preindustrial can reduce by 25%, more than twice decrease obtained orbital forcing alone. We identify tropical Atlantic mean state caused momentous strengthening West Africa Monsoon (WAM) as critical factors amplifying ENSO’s through Walker circulation. Our results thus potential WAM due anthropogenic warming influence future well.