EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Antarctic ozone hole modifies iodine geochemistry on the Antarctic Plateau

Andrea Spolaor1,2, François Burgay2,3, Rafael P. Fernandez4, Clara Turetta1,2, Carlos A. Cuevas5, Kitae Kim6, Douglas E. Kinnison7, Jean-François Lamarque7, Fabrizio De Blasi1,2, Elena Barbaro1,2, Juan Pablo Corella8, Paul Vallelonga9, Massimo Frezzotti10, Carlo Barbante1,2, and Alfonso Saiz-Lopez5
Andrea Spolaor et al.
  • 1National Research Council of Italy, Institute of Polar Sciences, Venice, Italy (
  • 2Department of Environmental Sciences, Informatics and Statistics, University Ca’Foscari of Venice, via Torino, 155 - 30172 Venice-Mestre, Italy
  • 3Paul Scherrer Institut, Laboratory of Environmental Chemistry, 5232 Villigen PSI, Switzerland
  • 4Institute for Interdisciplinary Science, National Research Council (ICB-CONICET), FCEN-UNCuyo, Mendoza, 5501, Argentina
  • 5Department of Atmospheric Chemistry and Climate, Institute of Physical Chemistry Rocasolano, CSIC, Madrid, Spain
  • 6Korea Polar Research Institute, Incheon 21990, Korea
  • 7National Center for Atmospheric Research, Boulder, CO, USA
  • 8CIEMAT, Department of the Environment (DMA), Madrid, Spain
  • 9Physics of Ice, Climate and Earth, Niels Bohr Institute, University of Copenhagen, Tagensvej 16, Copenhagen N2200, Denmark
  • 10Departement of Science, University of Roma Tre, Largo S. Leonardo Murialdo, 1 00146 Rom,a Italy

Polar stratospheric ozone has decreased since the 1970s due to anthropogenic emissions of chlorofluorocarbons and halons, resulting in the formation of an ozone hole over Antarctica. The effects of the ozone hole and the associated increase in incoming UV-radiation on terrestrial and marine ecosystems are well studied, however the impact on geochemical cycles of ice photoactive elements, such as iodine, remains almost unexplored. Here, we present the first iodine record from the inner Antarctic Plateau (Dome C) that covers approximately the last 212 years (1800-2012 CE). Our results show that iodine concentration in ice remained fairly constant during the pre-ozone hole period (1800-1974 CE) but has declined twofold since the onset of the ozone hole era (~1975 CE), closely tracking the total ozone evolution over Antarctica. Based on ice core observations, laboratory measurements and chemistry-climate model simulations, we propose that the iodine decrease since ~1975 is caused by enhanced iodine re-emission from snowpack due to the ozone hole driven increase in UV-radiation reaching the Antarctic Plateau. These findings suggest the potential for ice core iodine records from the inner Antarctic Plateau as an archive for past stratospheric ozone trends.

How to cite: Spolaor, A., Burgay, F., P. Fernandez, R., Turetta, C., Cuevas, C. A., Kim, K., Kinnison, D. E., Lamarque, J.-F., De Blasi, F., Barbaro, E., Corella, J. P., Vallelonga, P., Frezzotti, M., Barbante, C., and Saiz-Lopez, A.: Antarctic ozone hole modifies iodine geochemistry on the Antarctic Plateau, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-3777,, 2022.