Antarctic ozone hole modifies iodine geochemistry on the Antarctic Plateau

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 ecosyste...

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Bibliographic Details
Published in:Nature Communications
Main Authors: Spolaor, Andrea, Burgay, Francois, Fernandez, Rafael P., Turetta, Clara, Cuevas, Carlos A., Kim, Kitae, Kinnison, Douglas E., Lamarque, Jean-Francois, de Blasi, Fabrizio, Barbaro, Elena, Corella, Juan Pablo, Vallelonga, Paul, Frezzotti, Massimo, Barbante, Carlo, Saiz-Lopez, Alfonso
Format: Article in Journal/Newspaper
Language:English
Published: 2021
Subjects:
DOME-C
SEA-ICE
SNOW ACCUMULATION
MOLECULAR-IODINE
EAST ANTARCTICA
CHEMISTRY
EMISSIONS
BROMINE
VARIABILITY
TROPOSPHERE
Antarctic
East Antarctica
The Antarctic
Antarc*
Antarctica
ice core
Sea ice
Online Access:https://curis.ku.dk/portal/da/publications/antarctic-ozone-hole-modifies-iodine-geochemistry-on-the-antarctic-plateau(8d2134c7-b63e-4616-a057-74985af5fa58).html
https://doi.org/10.1038/s41467-021-26109-x
https://curis.ku.dk/ws/files/281985826/s41467_021_26109_x.pdf
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Summary: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 established; however, the impact on geochemical cycles of ice photoactive elements, such as iodine, remains mostly 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 the iodine concentration in ice remained constant during the pre-ozone hole period (1800-1974 CE) but has declined twofold since the onset of the ozone hole era (similar to 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 similar to 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 to be as an archive for past stratospheric ozone trends. The Antarctic ozone hole has had far-reaching impacts, but effects on geochemical cycles in polar regions is still unknown. Iodine records from the interior of Antarctica provide evidence for human alteration of the natural geochemical cycle of this essential element.

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