Alpine ice shows three-fold increase in atmospheric iodine

Analysis of iodine trapped in Alpine ice has shown that levels of atmospheric iodine have tripled over the past century, which partially offsets human-driven increases in the air pollutant, ozone.

The study showed, however that, although iodine can destroy 'bad' ozone, there isn't enough to counter all of the production. Researchers say it is now important to include iodine data in climate models that predict future global environmental outcomes.

Analysis of the Alpine ice, by scientists at the University of York, Universite Grenoble Alpes, and Desert Research Institute, shows that iodine concentration began to increase after the Second World War following the growth in motor vehicles and electricity generation.

Nitrogen oxide emissions from vehicles and power plants since the 1950s increases surface ozone, and this reacts with chemicals in seawater to release more iodine into the atmosphere, which partially, but not completely, destroys some of these harmful gases.

Professor Lucy Carpenter, from the University of York's Department of Chemistry, said: "Iodine's role in human health has been recognised for some time - it is an essential part of our diets.

"Its role in climate change and air pollution, however, has only been recently recognised, and up until now, there have been no historical records of iodine in populated regions such as Europe.

"Due to the difficulty in accessing this kind of data, the impact of iodine in the atmosphere is not currently a feature of the climate or air quality models that predict future global environmental changes."

The study in the European Alps has now provided new long-term insight into the delicate balance of ozone in the atmosphere.

Ozone in the lower atmosphere acts as an air pollutant and greenhouse gas, but ozone is also the main driver of iodine emissions from the ocean. Once released into the atmosphere iodine acts to destroy this 'bad' ozone.

The more ozone humans produce, the more iodine is released from the ocean which can then help destroy the ozone produced by humans. This means that iodine levels in the ocean can, at least partially, act to keep ozone gases in the lower atmosphere in check, but there isn't enough to counter all of the production.

Dr Tomas Sherwen, from the University of York's Department of Chemistry, said: "When we look at the concentrations of iodine over time, we can see that it was fairly steady during the industrial revolution.

"However as more cars appeared on the roads in the post-war period, we get more emissions of nitrogen oxides causing more ozone in the atmosphere and therefore more iodine.

"Surface ozone concentrations have stabilised over much of Europe and the Atlantic ocean, although are still growing over other regions.

"We can now start to think about factoring in our knowledge of iodine chemistry into climate and air quality models to help us better predict what the future of our atmosphere will look like around the globe."

Research paper

Related Links
University of York
Earth Observation News - Suppiliers, Technology and Application

Tweet

Thanks for being there;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Monthly Supporter
$5+ Billed Monthly

paypal only

SpaceDaily Contributor
$5 Billed Once

credit card or paypal

What's in the air? There's more to it than we thought
New Haven CT (SPX) Nov 05, 2018
Yale researchers have found that a type of air pollution is much more complicated than previous studies indicated. Using high-powered equipment to analyze air samples, the researchers were able to get a detailed look at the molecular makeup of organic aerosols, which have a significant presence in the atmosphere. Posing risks to health and climate, these airborne particles generally fall into two categories: Primary organic aerosols that can form during combustion, such as in car and truck exhaust ... read more