Strengthening of West African Monsoon during Green Sahara period may have affected El Nino Southern
Oscillation
https://phys.org/news/2017-07-west-african-monsoon-green-sahara.html
Accounting for a vegetated and less dusty Sahara reduces the variability of El Niño during the Mid-Holocene to closer to that which is observed in several paleoclimate records. This is shown by researchers at the Department of Meteorology at Stockholm University in a recent study, published in Nature Communications.
Changes in the El Niño Southern Oscillation (ENSO) - an important driver of large-scale climate variability - have broad impacts on society and eco-systems globally. Both observations and model simulations suggest that with the current trend in global warming, we may see changes in ENSO behaviour. Understanding how ENSO has varied historically and the causes of this variability is paramount for predicting the future.
Many paleoclimate records from the warm Mid-Holocene (4,000 - 7,000 yrs BP) show that variations in ENSO were reduced by 30%-60% compared to pre-industrial times. This is not accurately captured by most climate models, which show a modest reduction of 10% using only changes in the Earth's orbital parameters.
Our study accounts for a vegetated and less dusty Sahara. This reduces the variability of the Mid-Holocene ENSO with up to 25% compared to the pre-industrial, more than twice the decrease found by using orbital forcings alone, says Francesco S.R. Pausata, researcher at the Department of Meteorology at Stockholm University (MISU).
Read more at: https://phys.org/news/2017-07-west-african-monsoon-green-sahara.html#jCp