The optical properties of aerosols
Measurements of the optical properties of aerosol are crucial to quantify more accurately the impact of aerosol on climate and to provide more accurate parameteizations for radiative transfer models. In this project we are examining the influence of environmental conditions, particle size, composition and phase on light scattering and absorption by single aerosol particles. Using a Bessel beam optical trap, we are able to capture individual particles as small as 400 nm. Then, their extinction cross-sections can be measured directly by single particle cavity ringdown spectroscopy.
For examples, see:
B.J. Mason, J.S. Walker, J.P. Reid and A.J. Orr-Ewing*, 'Deviations from Plane-Wave Mie Scattering and Precise Retrieval of Refractive Index for a Single Spherical Particle in an Optical Cavity', J. Phys. Chem. A. 118 (2014) 2083-2088 - pdf
J.S. Walker, A.E. Carruthers, A.J. Orr-Ewing and J.P. Reid, 'Measurements of Light Extinction by Single Aerosol Particles', Journal of Physical Chemistry Letters 4 (2013) 1748-1752 - pdf