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Assistant Professor of Chemistry, Oregon State University

“Tiny particles, large surfaces: Using single particle spectroscopy to elucidate aerosol surface properties and their impact on clouds.”

Official/Unofficial Bio

Aerosols, solid and liquid particles suspended in the gas phase, are present in the atmosphere all across the globe. These particles are smaller than 1/10 the diameter of a human hair but play a significant role in the global climate and precipitation. These particles can directly impact the climate by scattering and absorbing incoming solar radiation, and also indirectly impact the climate and precipitation by affecting the formation and subsequent properties of clouds. Chemical transformations of these particles in the atmosphere can also impact both their direct and indirect climate impacts. The physical properties of aerosol particles (e.g., hygroscopicity, surface-area-to-volume ratio, and surface tension), which are impacted by their chemical properties, play an important role in these climate impacts.

Single-particle spectroscopy has proven to be a powerful tool to study aerosol properties. By confining a single aerosol particle in air for analysis, the contactless nature and conditions of the atmosphere can be mimicked in the lab. Importantly, this allows for the high surface-area-to-volume of single droplets, which is not well mimicked by a bulk solution, to be achieved. Using single-particle spectroscopy, we study the partitioning of surfactants to aerosol droplet surfaces and apply these measurements to understand how surfactants, that are naturally present in atmospheric aerosol (e.g., surfactants from the sea surface microlayer in sea spray aerosol), can impact the formation of cloud droplets.

**This seminar counts towards the chemistry major seminar attendance requirement