Ozone loss in the stratosphere over Antarctica has increased rainfall in subtropical parts of South America.

Summers in Uruguay, Paraguay, southern Brazil and northern Argentina became markedly wetter over the second half of the twentieth century. To pin down whether this was due to the impact of ozone on atmospheric circulation and precipitation in the region, Paula Gonzales and her group at Columbia University in New York contrasted simulations with and without ozone depletion using six climate models. Although results were mixed regarding the impact of greenhouse gases, simulations consistently reproduced observed rainfall trends more accurately when ozone loss was included.

Precipitation in the region should stabilize or decrease as ozone over the Antarctic recovers, the authors suggest.

Clim. Dyn. http://dx.doi.org/10.1007/s00382-013-1777-x (2013)