Abstract
A reduction in dust over North Africa during the mid-Holocene “Green Sahara” period could have amplified precipitation, helping reconcile climate model simulations with paleo-precipitation reconstructions. Here we test this using general circulation model simulations including interactive dust. We calculate a dust-precipitation amplification factor using three different dust configurations to evaluate the sensitivity to dust optical properties and particle size range. The resultant amplification ranges from −20% to 50%. With more absorbing dust properties, there is a large negative net radiative effect and hence a larger impact on the hydrological cycle. With the inclusion of particles greater than 1 μm in radius, the precipitation amplification is reversed. Based on the simulations which best match observed Saharan dust properties, we conclude that there was a limited enhancement of precipitation due to reduced dust during the mid-Holocene, meaning other aspects of the climate system should be the focus of future research.
Original language | English |
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Pages (from-to) | 1612-1621 |
Number of pages | 10 |
Journal | Geophysical Research Letters |
Volume | 46 |
Issue number | 3 |
Early online date | 27 Dec 2018 |
DOIs | |
Publication status | Published - 16 Feb 2019 |
ASJC Scopus subject areas
- Geophysics
- Earth and Planetary Sciences(all)
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One the role of dust-climate forcing during the mid-Holocene
Hopcroft, P. (Creator), University of Bristol, 1 Dec 2018
https://www.paleo.bristol.ac.uk/ummodel/scripts/papers/Hopcroft_Valdes_2019.html
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Birmingham Environment for Academic Research (BEAR)
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