Abstract
The African easterly jet (AEJ) and African easterly waves (AEWs) can have both local and far-reaching impacts on weather. It is therefore crucial to understand how the AEJ and AEWs will respond to future climate change. In this study, we examine anthropogenic influences on the AEJ–AEW system using the Weather Research and Forecasting (WRF) model configured as a tropical channel model (TCM). Hindcast simulations for the years 2001–2010 were performed using the WRF TCM, and ten additional years of simulations were performed using the pseudo-global warming method with the initial and boundary conditions of the model modified as if it were the late twenty-first century. A comparison of the simulations from the two climate scenarios indicates robust changes to both the AEJ and AEWs. For the AEJ, the jet is weaker and shifted northwards and upwards in the future climate, in association with an increase in precipitation over the Sahel and a strengthening of the meridional temperature gradient. For the AEWs, there is an increase in the number and strength of the waves in the future climate, in association with an increase in the baroclinic and barotropic energy conversions. The barotropic energy conversion in particular has a larger contribution in the future climate, which manifests in the southern AEW track experiencing greater future strengthening than the northern track.
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Availability of data and materials
All data used in this work are located on the U.S. Department of Energy server Cori.
Code availability
The AEW tracking code is located on GitHub.
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Acknowledgements
The authors thank Dr. Elinor Martin and one anonymous reviewer for their constructive comments that have improved the manuscript. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Biological and Environmental Research, Climate and Environmental Sciences Division, Regional and Global Model Analysis Program, under Award Number DE-AC02-05CH11231. C.M.P. acknowledges support from the U.S. Department of Energy, Office of Science, Office of Biological and Environmental Research (BER), Earth and Environmental Systems Modeling (EESM) Program, under Early Career Research Program Award Number DE‐SC0021109. This work used the Extreme Science and Engineering Discovery Environment (XSEDE) computing resource Stampede2, which is supported by National Science Foundation grant number ACI-1548562, through allocations ATM190012 and ATM190016. The authors acknowledge the Texas Advanced Computing Center (TACC) at The University of Texas at Austin for providing HPC resources that have contributed to the research results reported within this paper. URL: http://www.tacc.utexas.edu. The data used in this paper are available on the DOE server Cori. The authors thank Alan Brammer for his contribution to the African easterly wave tracking code.
Funding
This material is based upon work supported by the US Department of Energy, Office of Science, Office of Biological and Environmental Research, Climate and Environmental Sciences Division, Regional and Global Model Analysis Program, under Award Number DE-AC02-05CH11231. C.M.P. acknowledges support from the U.S. Department of Energy, Office of Science, Office of Biological and Environmental Research (BER), Earth and Environmental Systems Modeling (EESM) Program, under Early Career Research Program Award Number DE‐SC0021109. This work used the Extreme Science and Engineering Discovery Environment (XSEDE) computing resource Stampede2, which is supported by National Science Foundation grant number ACI-1548562, through allocations ATM190012 and ATM190016.
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Bercos-Hickey, E., Patricola, C.M. Anthropogenic influences on the African easterly jet–African easterly wave system. Clim Dyn 57, 2779–2792 (2021). https://doi.org/10.1007/s00382-021-05838-1
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DOI: https://doi.org/10.1007/s00382-021-05838-1