Mt. Erebus, the largest point source of NO2 in Antarctica

Abstract

Abstract We report here the first observations of NO 2 emission from Mt. Erebus, a volcano with an active lava lake located on Ross Island, Antarctica. Erebus generates a persistent plume, which is entrained at an altitude of about 4 km above sea level. Its NO 2 flux, measured by scattered light ultraviolet spectroscopy in December 2003, was equivalent to ∼0.6 Gg (N) yr −1 . The total reactive nitrogen supply may be significantly higher than this since other NO y species are likely to have been present in the plume. We believe the NO 2 is generated by thermal fixation of atmospheric nitrogen at the hot lava surface, forming NO, which then reacts rapidly with oxidants including ozone to yield NO 2 . Erebus volcano has displayed lava lake activity for many decades and may, therefore, play a significant long-term role in Antarctic tropospheric chemistry, and represent an important source of nitrogen deposited to the ice surface.