Muted Amazon Rainfall Response to Deforestation in a Global Storm-Resolving Model

Abstract

Ongoing Amazon deforestation has raised concerns about forest dieback via induced precipitation changes. Previous studies have found that complete deforestation reduces evapotranspiration, contributing to low precipitation rates that would limit the regrowth of the forest, but such studies have used climate models with convective parameterization and/or fixed large-scale circulation. For the first time, we simulate a complete Amazon deforestation scenario without convective parameterization, allowing full interaction between convection and large-scale circulation, for 3 years. Our results show no significant reduction in annual mean precipitation. Changes in the 700 hPa circulation and associated moisture convergence compensate for the reduction in evapotranspiration. These changes also lead to a north-south dipole pattern in the precipitation response during the dry and wet seasons. The uncovered dynamics suggest that Amazon mean precipitation may be more resilient to land surface perturbations than previously thought.