The eruption of the Kasatochi volcano in Alaska on 7th August 2008 released a large amount of BrO (and other gases, such as SO₂) in the atmosphere which could be followed by the GOME-2 instrument during several days after the eruption.
Lagrangian dispersion modeling results, based on the FLEXPART tool, show that the volcanic BrO was directly injected in the upper troposphere/lower stratosphere at altitudes ranging from 8 to 12 km, and that the total mass of reactive bromine released in the atmosphere was around 50-120 tons.
These results represent the first space-based observation of BrO emissions due to volcanic activity.

Reference:
Theys, N., M. Van Roozendael, B. Dils, F. Hendrick, N. Hao, and M. De Mazière (2009),
First satellite detection of volcanic bromine monoxide emission after the Kasatochi eruption,
Geophys. Res. Lett., 36, L03809, doi:10.1029/2008GL036552.