(John Wiley & Sons, 2017-09-09)
Zhang, Lei; Rechtman, Thomas; Karnauskas, Kristopher B.; Li, Laifang; Donnelly, Jeffrey P.; Kossin, James P.
The latitudinal gradient of outgoing longwave radiation (OLR) over Africa is a skillful and
physically based predictor of seasonal Atlantic hurricane activity. The African OLR gradient is observed to
have strengthened during the satellite era, as predicted by state-of-the-art global climate models (GCMs) in
response to greenhouse gas forcing. Prior to the satellite era and the U.S. and European clean air acts, the
African OLR gradient weakened due to aerosol forcing of the opposite sign. GCMs predict a continuation of
the increasing OLR gradient in response to greenhouse gas forcing. Assuming a steady linear relationship
between African easterly waves and tropical cyclogenesis, this result suggests a future increase in Atlantic
tropical cyclone frequency by 10% (20%) at the end of the 21st century under the RCP 4.5 (8.5)
forcing scenario.
