Aerosols: Chemists develop new approaches to understanding disturbing trends near Earth's surface

"The extreme weather we have had in recent years is but one example of the highly complex, global science-based challenges we are now living with," said ACS President Marinda Li Wu, Ph.D. "The climate research conducted by CAICE is providing startling insights that I believe will prove to be as important in protecting human health as the ozone research of 30 years ago."

The current research is being led by Kimberly Prather, Ph.D., director of CAICE and UCSD Distinguished Chair in Atmospheric Chemistry, and Vicki Grassian, Ph.D., co-director of CAICE and F. Wendell Miller Professor, Department of Chemistry, The University of Iowa. Grassian is also an ACS Fellow.

Thirty years ago, scientists discovered that chlorofluorocarbons degraded ozone high above Earth's surface. Furthermore, particulates, specifically polar stratospheric clouds, played a role in these processes. Subsequently, the Montreal Protocol, an international treaty signed in 1987, was enacted, fostering policies that have protected the ozone layer, and thus, people, from intense ultraviolet radiation ever since.

Now, the team led by Prather and Grassian is studying how the more complex troposphere is impacted by aerosols, particulates suspended in the air that can circle the globe in a matter of weeks or even just days. These particulates are emitted from a wide range of sources, including coal-fired power plants, vehicles, wildfires, volcanoes, desert dust and even sea spray. Depending on their chemical make-up, aerosols have been shown to have a vast array of environmental effects, impacting cloud formation, precipitation levels and human health. Yet, aerosols are the most poorly understood component of our atmosphere.