Tuesday September 1st
Surface active organic aerosol: experiments, models, and atmospheric impact.
Associate professor, University of Oulu. Head of Atmospheric Research (ATMOS) Group, Oulu, Finland
Surface active components have been identified in atmospheric aerosols from a wide range of environments and can significantly reduce aqueous surface tension, but their effects on aerosol properties and in particular cloud microphysics are not fully constrained. Surface tension is a key parameter in Köhler theory, but predicted size-dependent variations in finite-sized droplet surface tension compared to macroscopic solutions can introduce large variations in cloud condensation nucleus (CCN) activity and cloud radiative forcing. Over the last decades, we have studied aerosol surface activity via measured CCN activity and from the highly specific composition of aqueous solution surfaces observed with synchrotron radiation excited spectroscopy. Recently, we presented the first direct measurements of surface tension for finite-sized surfactant-containing droplets, showing that droplet surface tension is elevated in a manner consistent with thermodynamic predictions that account for size-dependent bulk/surface partitioning of surface active components, but over-estimated by the widely used Gibbsian adsorption models.
About the author:
Nønne Prisle leads the Atmospheric Research (ATMOS) group at University of Oulu, Finland. She is an Academy of Finland Research Fellow and currently PI of research projects funded by the European Research Council, Academy of Finland, and the Tiina and Antti Herlin foundation. Spearheaded by three complementary research teams specialized in novel synchrotron radiation based imaging and spectroscopic methods for aerosol characterization, quantum chemistry, classical thermodynamics, and atmospheric modeling, and artificial intelligence and machine learning, her research group focuses on unravelling properties of atmospheric aerosols from the molecular level to their global impacts, with a keen eye on the elusive role of surface active organics in atmospheric water.
Prof. Prisle obtained her B.Sc. in theoretical physics from University of Southern Denmark (2004), Ph.D. in chemistry from University of Copenhagen (2009), and has been a postdoctoral fellow at Finnish Meteorological Institute, Helsinki University’s Division of Atmospheric Science (now INAR), and Georgia Institute of Technology. She is vice chair of the board of Finnish Synchrotron Users Organization (FSRUO), board member of the Finnish Association for Aerosol Research (FAAR) and spokesperson for atmospheric research at the Finnish-Estonian Beamline for Atmospheric and Materials Science (FinEstBeAMS) at the MAX IV synchrotron facility. She is a speaker of TEDxOulu – Arctic Matters (2020), keynote presenter at the Symposium for Climate Change and World Peace at the air Guitar World Championship (2019), and co-contributor to the graphic novel “Little Things” about her research.