[PAST EVENT] Chemistry Spring Seminar

March 23, 2018
3pm - 4:20pm

Prof. Akua Asa-Awuku of the University of Maryland presents

"Why are Aerosols important? Understanding the Links Between Air Quality and Climate"

Aerosols, or particles, emitted into the air have adverse effects for regional air quality and health. In addition, aerosols significantly impact earth?s climate and the hydrological cycle. They can directly reflect the amount of incoming solar radiation into space; by acting as cloud condensation nuclei (CCN), they can indirectly impact climate by affecting cloud albedo. Our current assessment of the interactions of aerosols and clouds is uncertain and parameters used to estimate cloud droplet formation in global climate models are not well constrained. Organic aerosols attribute much of the uncertainty in these estimates and are known to affect the ability of aerosol to form cloud droplets by i) providing solute, thus reducing the equilibrium water vapor pressure of the droplet and ii) acting as surfactants capable of depressing surface tension, and potentially, growth kinetics. Understanding the chemical and thermodynamic properties that control the ability of particles to form droplets, CCN activity, and droplet growth are necessary for constraining impacts on the hydrological cycle and uncertainties from the aerosol indirect effect. In particular, quantifying organic effects that are not well understood are important for predicting water uptake, CCN concentrations and cloud droplet formation. In this presentation, we explore and identify parameters that affect droplet growth and discuss the links between cloud formation and air quality.