Geophys. Res. Lett. 38, L19802 (2011)

Replacing forest with pasture or cropland often produces sharp gradients in the landscape, which tend to generate local temperature-induced circulation patterns called 'vegetation breezes' — analogous to sea breezes. These breezes enhance rainfall-generating convection currents.

Luis Garcia-Carreras and Douglas Parker from the Institute for Climate and Atmospheric Science at the University of Leeds, UK, used an ensemble of atmospheric cloud-resolving model simulations to investigate the potential impact of deforestation-generated vegetation breezes on local rainfall.

The results indicate that variation in vegetation cover increases the total locally generated rainfall on average by 13% and produces a particularly pronounced four- to sixfold increase in rainfall over cropland boundaries compared with uniform land cover. However, rainfall was not enhanced everywhere, and was actually reduced by 50% or more over the forest. The authors note that these local- to medium-scale processes can interact with large-scale atmospheric circulation in complex ways, so predicting the change in total precipitation due to deforestation is an ongoing research aim.