An international team led by CU Boulder researchers has cracked the chemical code driving the formation of iodine particles in the atmosphere, revealing how the element contributes to increased cloud cover and depletes molecules in the Earth’s protective ozone layer.
The research, conducted at the world’s largest particle physics laboratory, the European Organization for Nuclear Research (CERN), was published today in the journal Nature Chemistry. It’s the first time that any experiment in the world has demonstrated the mechanism for how the gas-phase form of iodine—known as iodic acid—forms, and suggests it has a catalytic role in atmospheric particle formation.
It comes at a time when atmospheric iodine is increasing globally, with current levels triple what they were 70 years ago. Researchers hope that this new knowledge on iodine’s atmospheric interactions can be added to global atmospheric and climate models to help scientists better understand its environmental impacts—such as increased cloud cover, which could exacerbate global warming-related thinning of Arctic sea ice.
“This paper establishes a link between the sources of iodine, how they are emitted into the atmosphere, and particle formation, which through subsequent growth, seeds clouds,” said Rainer Volkamer, co-lead author on the paper, professor of chemistry at CU Boulder and fellow at the Cooperative Institute for Research in Environmental Sciences (CIRES). “That link didn't exist before, and now we have established that link at the molecular level."
Read more at University of Colorado at Boulder
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