Chemistry professor's cloud research receives national attention

To quote Marlene Cimons reporting for the National Science Foundation, "When Pierre Herckes goes to the top of a mountain, it's not for the view. In fact, the more clouds and fog, the better."

Pierre Herckes is an associate professor in the Department of Chemistry and Biochemistry in ASU's College of Liberal Arts and Sciences. He studies how cloud droplets act as miniscule chemical reactors that can transform atmospheric gases and particles into new and sometimes threatening chemical forms. This has a direct impact on atmospheric composition with implications for human health and global climate.

The health related aspect of Herckes's research stems from chemical reactions in clouds or fogs that might transform some relatively innocent chemicals into, for example, the potent carcinogen and mutagen, N-nitroso dimethylamine (NDMA). Herckes is tackling the problem through laboratory and observational field studies.

“We don’t completely understand the way particles are actually formed in the atmosphere,” explains Herckes. “This is a big problem for air quality and climate models since we know the effects of primary emissions in the atmosphere, but don’t understand well the importance of secondary particles, that is, these particles that are formed in the atmosphere from gases.”

“We are interested in the chemistry going on, and physically, which particles and gases get into cloud droplets and which don’t,” he says. “We want to better understand the particle/cloud interactions, which are some of the highest uncertainties in climate modeling. We know quite well what gases do. A substantial part of the uncertainties of climate are based on what the particles do, and how they interact with clouds. The particles can be warming, but they also can be cooling and impact the frequency and amount of precipitation."