Abstract
The impact of climate change on Sahel precipitation suffers from large uncertainties and is strongly model-dependent. In this study, we analyse sources of inter-model spread in Sahel precipitation change by decomposing precipitation into its dynamic and thermodynamic terms, using a large set of climate model simulations. Results highlight that model uncertainty is mostly related to the response of the atmospheric circulation to climate change (dynamic changes), while thermodynamic changes are less uncertain among climate models. Uncertainties arise mainly because the models simulate different shifts in atmospheric circulation over West Africa in a warmer climate. We linked the changes in atmospheric circulation to the changes in Sea Surface Temperature, emphasising that the Northern hemispheric temperature gradient is primary to explain uncertainties in Sahel precipitation change. Sources of Sahel precipitation uncertainties are shown to be the same in the new generation of climate models (CMIP6) as in the previous generation of models (CMIP5).
| Original language | English |
|---|---|
| Pages (from-to) | 1385-1401 |
| Number of pages | 17 |
| Journal | Climate Dynamics |
| Volume | 55 |
| Issue number | 5-6 |
| Early online date | 20 Jun 2020 |
| DOIs | |
| Publication status | Published - 1 Sept 2020 |
Bibliographical note
Funding Information:Caroline M Wainwright’s contribution has been supported by the NERC/DFID HyCristal project (NE/M020371/1). She is also grateful to the Mars Wrigley Confectionery research team for stimulating discussions on the wider context and applications of this work. Authors thank Dr. Robin Chadwick for his insightful and constructive comments on the precipitation decomposition. We acknowledge the World Climate Research Programme’s Working Group on Coupled Modelling, which is responsible for CMIP, and we thank the climate modelling groups for producing and making available their model output. For CMIP the U.S. Department of Energy’s Program for Climate Model Diagnosis and Intercomparison provides coordinating support and led development of software infrastructure in partnership with the Global Organization for Earth System Science Portals. GPCC and GPCP Precipitation data are provided by the NOAA/OAR/ESRL PSL, Boulder, Colorado, USA, from their Web site at https://psl.noaa.gov/ .
Funding Information:
Caroline M Wainwright?s contribution has been supported by the NERC/DFID HyCristal project (NE/M020371/1). She is also grateful to the Mars Wrigley Confectionery research team for stimulating discussions on the wider context and applications of this work. Authors thank Dr. Robin Chadwick for his insightful and constructive comments on the precipitation decomposition. We acknowledge the World Climate Research Programme?s Working Group on Coupled Modelling, which is responsible for CMIP, and we thank the climate modelling groups for producing and making available their model output. For CMIP the U.S. Department of Energy?s Program for Climate Model Diagnosis and Intercomparison provides coordinating support and led development of software infrastructure in partnership with the Global Organization for Earth System Science Portals. GPCC and GPCP Precipitation data are provided by the NOAA/OAR/ESRL PSL, Boulder, Colorado, USA, from their Web site at https://psl.noaa.gov/.
Publisher Copyright:
© 2020, The Author(s).
Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
Keywords
- Atmospheric circulation
- Climate models
- Projected changes
- Uncertainties
- West Africa
ASJC Scopus subject areas
- Atmospheric Science
