Stratospheric aerosols, polar stratospheric clouds, and polar ozone depletion after the Mount Calbuco eruption in 2015

We investigate the impact of the 2015 Mount Calbuco eruption and previous eruptions on stratospheric aerosols, polar stratospheric clouds, and ozone depletion using the Community Earth System Model coupled with the Community Aerosol and Radiation Model for Atmospheres compared with several satellite and balloon observations. The modeled volcanic sulfate aerosol size distribution agrees with the Light Optical Aerosol Counter observation at the Reunion Island site (21 degrees S, 55 degrees E) on 19 August at 20 km within estimated 0.1- to 1-mu m radius error bars.

Both the observed and simulated backscatter and extinction show that volcanic sulfate aerosol from the Mount Calbuco eruption was transported from midlatitude toward the Antarctic and slowly descended during transport. They also indicate that the SO2 emission into the stratosphere from Mount Calbuco is 0.2-0.4 Tg. The modeled number density indicates that the volcanic sulfate aerosol from the Mount Calbuco eruption penetrated into the Antarctic polar vortex in May and thereafter and reduced the polar stratospheric clouds effective radius.