ChBE Seminar Series: Akua Asa Awuku
Tuesday, May 6, 2014
11:00 a.m.-12:00 p.m.
Room 2108, Chemical and Nuclear Engineering Building
Professor Ganesh Sriram
Do we understand Aerosol-Cloud Climate Interactions? Linking Organic Aerosol Properties to Cloud Condensation Nuclei
Akua Asa Awuku
Chemical and Environmental Engineering
Bourns College of Engineering – Center for Environmental Research and Technology
University of California–Riverside
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 CCN concentrations and cloud droplet formation. In this presentation, we explore and identify parameters that affect organic droplet growth and discuss the links between cloud formation and air quality.
About the Speaker
Akua Asa-Awuku received her Ph.D. in Chemical Engineering from the Georgia Institute of Technology in 2008. She also earned her M.S in Chemical Engineering at Georgia Tech in 2006. She received her B.S in Chemical Engineering from the Massachusetts Institute of Technology in 2003. In 2008, Dr. Asa-Awuku served as a Camille and Henry Dreyfus Postdoctoral Fellow at the Center for Atmospheric Particle Studies and Chemical Engineering Department at Carnegie Mellon University. Currently, she is an assistant professor in the Chemical and Environmental Engineering department at the University of California Riverside. Dr. Asa-Awuku also has an appointment at the UC Riverside Bourns College of Engineering- Center for Environmental Research and Technology. Dr. Asa-Awuku's primary research interest is understanding and predicting aerosol-cloud climate interactions. Her research explores the water-uptake of organic particles as it pertains to aerosol hygroscopicity, cloud condensation nuclei activation and droplet growth.