Planet‐Wide Ozone Destruction in the Middle Atmosphere on Mars During Global Dust Storm
Frank Daerden, Lori Neary, M. J. Wolff, R. T. Clancy, Franck Lefèvre, J. A. Whiteway, S. Viscardy, Arianna Piccialli, Yannick Willame, C. Depiesse, Shohei Aoki, Ian Thomas, Bojan Ristic, Justin Erwin, Jean‐Claude Gérard, Brad J. Sandor, Alain Khayat, M. D. Smith, Jon Mason, Manish Patel, Gerónimo Villanueva, Giuliano Liuzzi, G. Bellucci, J. J. López‐Moreno, Ann Carine Vandaele
Abstract
Abstract The Nadir and Occultation for MArs Discovery (NOMAD)/UV‐visible (UVIS) spectrometer on the ExoMars Trace Gas Orbiter provided observations of ozone (O 3 ) and water vapor in the global dust storm of 2018. Here we show in detail, using advanced data filtering and chemical modeling, how Martian O 3 in the middle atmosphere was destroyed during the dust storm. In data taken exactly 1 year later when no dust storm occurred, the normal situation had been reestablished. The model simulates how water vapor is transported to high altitudes and latitudes in the storm, where it photolyzes to form odd hydrogen species that catalyze O 3 . O 3 destruction is simulated at all latitudes and up to 100 km, except near the surface where it increases. The simulations also predict a strong increase in the photochemical production of atomic hydrogen in the middle atmosphere, consistent with the enhanced hydrogen escape observed in the upper atmosphere during global dust storms.