The influence of remote aerosol forcing from industrialised economies on the future evolution of East and West African rainfall

Scannell, C., Booth, B. B. B., Dunstone, N. J., Rowell, D. P., Bernie, D. J., Kasoar, M., Voulgarakis, A., Wilcox, L. J. ORCID: https://orcid.org/0000-0001-5691-1493, Acosta Navarro, J. C., Seland, Ø. and Paynter, D. J. (2019) The influence of remote aerosol forcing from industrialised economies on the future evolution of East and West African rainfall. Journal of Climate, 32 (23). pp. 8335-8354. ISSN 1520-0442 doi: 10.1175/jcli-d-18-0716.1

Abstract/Summary

Past changes in global industrial aerosol emissions have played a significant role in historical shifts in African rainfall and yet assessment of the impact on African rainfall of near term (10-40 year) potential aerosol emission pathways remains largely unexplored. Whilst existing literature links future aerosol declines to a northward shift of Sahel rainfall, existing climate projections rely on RCP scenarios that do not explore the range of air quality drivers. Here we present projections from two emission scenarios that better envelope the range of potential aerosol emissions. More aggressive emission cuts results in northward shifts of the tropical rain-bands whose signal can emerge from expected internal variability on short, 10-20 year, time horizons. We also show for the first time that this northward shift also impacts East Africa, with evidence of delays to both onset and withdrawal of the Short Rains. However, comparisons of rainfall impacts across models suggest that only certain aspects of both the West and East African model responses may be robust, given model uncertainties. This work motivates the need for wider exploration of air quality scenarios in the climate science community to assess the robustness of these projected changes and to provide evidence to underpin climate adaptation in Africa. In particular, revised estimates of emission impacts of legislated measures every 5-10 years would have a value in providing near term climate adaptation information for African stakeholders.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/86332
Identification Number/DOI	10.1175/jcli-d-18-0716.1
Refereed	Yes
Divisions	Science > School of Mathematical, Physical and Computational Sciences > Department of Meteorology
Uncontrolled Keywords	Atmospheric Science
Publisher	American Meteorological Society
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