Investigating the mechanism of ice nucleation by size-fractionated macromolecules found in ambient aerosols in the UK and in Canada.

Lead Research Organisation: University of Leeds
Department Name: School of Earth and Environment

Abstract

EPSRC: Kathleen Thompson: EP/S023593/1

Atmospheric ice formation can alter cloud properties, impacting precipitation and cloud lifetimes. Understanding the microphysical processes which control ice formation in clouds is vital for reducing climate uncertainties. For example, ice nucleating particles (INPs) induce the freezing of water droplets in clouds, therefore, understanding the nature and abundance of these particles in the atmosphere is important for improving our understanding of the aerosol-cloud radiative effects on climate. The proposed research aims to fill the vital research gap of understanding the mechanism by which macromolecules nucleate ice in clouds. I aim to do this by taking samples collected in the UK, with known ice nucleating ability, to the University of British Columbia to investigate their surfactant properties. I will use a tensiometer to measure their surface tension, interpret the surfactant concentration of the biological INP and correlate ice nucleating ability with surfactant concentrations. This project is innovative as it uses real ambient samples and unique instrumentation for the field of atmospheric ice nucleation. The outcome of this will help us to better understand the nature of biological INP in the atmosphere and use their potential surface tension properties to predict ice formation in clouds as a result of changes in concentrations of organic aerosol.

Publications

10 25 50