Tropospheric Iodine monoxide distribution from MAXDOAS observations at three Antarctic stations during the 2015-2023 period.

The tropospheric distribution of iodine monoxide (IO) in Antarctica remains an open question, as there are some uncertainties concerning, for example, its geographical and vertical distribution. Accurate long-term measurements of IO are important to understand its role in the tropospheric composition of this region, where continuous ground-based observations of IO are very rare and satellite observations have some limitations.   INTA's Antarctic activities include MAXDOAS measurements since 2011 in the framework of several nationally funded projects such as MARACA, VIOLIN, HELADO, VHODCA and currently GARDENIA. The collaboration with the Argentinean National Antarctic Directorate has allowed MAXDOAS measurements at three different locations: Ushuaia (54ºS), located in Tierra del Fuego and at the Antarctic stations of Marambio (64ºS) and Belgrano (78ºS). This paper presents the vertical distribution of tropospheric IO obtained from MAXDOAS measurements at the aforementioned sites over a nine-year period (2015-2023). Note that a similar work but based on observations of bromine monoxide from Antarctica will be presented here at EGU2024 in the work of Prados-Román et al. (2024).