Simulated remote vegetation-climate feedbacks modulate African tropical rainfall under climate change

Abstract:

We investigated vegetation feedbacks on the large-scale climate change over the African continent using a fully coupled regional vegetation-climate model called RCA-GUESS, which accounts for the major biogeophysical feedback mechanisms coupling the atmosphere to the land surface and vegetation at regional scale. We conducted three long-term transient climate change experiments driven by the CanESM2 GCM under the future climate scenarios RCP8.5, and investigated future changes in African vegetation dynamics as well as the effects of regional vegetation-related feedbacks on climate. We found that changes in vegetation over savannah under climate change not only impose important local effects on regional climate by altering surface energy fluxes, but they also produce meso-scale remote effects on central Africa by modulating land-ocean temperature gradient, lower boundary layer circulation, and moisture inflow from ocean to land, thus influencing the strength of precipitation over convection-dominant region. This emphasizes the importance of representing vegetation dynamics in regional Earth System Models particularly for the region with strong vegetation dynamics such as Africa.