Field observation study reveals rapid sulfur conversion and ozone depletion in the Erebus volcanic plume, highlighting reactive tropospheric chemistry in Antarctica.
Key Points
To measure and characterize the downwind chemical evolution of trace gases emitted in the atmospheric plume of Mount Erebus, Antarctica.
Conducted ground-based infrared spectrometry at the crater rim of Mount Erebus in December 2005.
Sampled the volcanic plume up to 56 km downwind using a Twin Otter aircraft, covering plume ages from under 1 minute to 9 hours.
Measured downwind SO2/CO ratios at approximately 20% of crater rim values, signaling rapid chemical conversion of SO2 into sulfate aerosols.
Identified volcanogenic H2SO4, HNO3, and pernitric acid (HO2NO2), while near-source NOx was completely oxidized downwind.
Observed localized ozone (O3) depletion of up to ~35% downwind, attributed to heterogeneous reactions involving reactive halogens such as BrO and ClO.