Quantitative detection of iodine in the stratosphere
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Ozone pollution at the Earth’s surface could be destroying ozone in the lower reaches of the ozone layer via atmospheric iodine.
The ozone layer shields the Earth from harmful ultraviolet radiation from the Sun. Ozone levels in the upper stratosphere have been recovering since chlorofluorocarbons were banned in 1989, but they have been continuing to drop in the lower stratosphere.
The culprit could be atmospheric iodine, according to airplane measurements by a team that included researchers at the Spanish National Research Council. For the first time, they have quantitatively detected iodine in the lower stratosphere — and at levels that could cause significant destruction of the ozone there.
Ironically, ozone production at ground level could be responsible for the destruction of ozone in the lower stratosphere since it can release iodine from the oceans.
- PNAS 117, 1860–1866 (2020). doi: 10.1073/pnas.1916828117