Acetone Atmospheric Distribution Retrieved from Space

Abstract : As one of the most abundant oxygenated volatile organic compounds in the atmosphere, acetone (CH₃C(O)CH₃) influences atmospheric oxidants levels and ozone formation. Here, we report the first unambiguous identification of acetone from the nadir‐viewing satellite sounder IASI. Via a neural network‐based retrieval approach that was previously applied to the retrieval of other weak absorbers, we obtain daily global acetone retrievals. A first inter‐comparison with independent measurements is conducted. As the retrieval method is computationally fast, it allowed the full reprocessing of the 2007–2018 IASI time series. Analysis of the retrieved global product and its seasonality suggests that emissions of acetone and precursors from the terrestrial biosphere at Northern Hemisphere mid‐ and high‐latitudes, are the main contributors to the atmospheric acetone abundance, more than year‐round oxidation of anthropogenic isoalkanes. Remarkably, biomass burning does not appear to be a strong global source of acetone.