Measurements of iodine monoxide from GOME-2 over Antarctica

Abstract

Iodine monoxide (IO) plays an important role in tropospheric chemistry, including catalytic ozone depletion, changes in the OH/HO2 and NO/NO2 ratio, and new particle formation. Its chemistry is especially significant in the Antarctic region, exhibiting a seasonality in which the largest concentrations are found in springtime. The Global Ozone Monitoring Experiment-2 (GOME-2), onboard the MetOp-A satellite, is a scanning spectrometer that captures sunlight reflected from the Earth's surface and atmosphere. With a spatial resolution of 80 × 40 km2, the spectrometer splits the light into its spectral components to map concentrations of atmospheric ozone as well as nitrogen dioxide, sulphur dioxide, other trace gases and ultraviolet radiation. Here, the retrieval method will be discussed, and the spatial and temporal distribution of the total column density measurements of IO over Antarctica will be presented.