AAAR 36th Annual Conference October 16 - October 20, 2017 Raleigh Convention Center Raleigh, North Carolina, USA
Abstract View
Solving the Inverse Problem for Coarse-mode Aerosol Morphology
MATTHEW BERG, Yuli W. Heinson, Osku Kemppinen, Stephen Holler, Kansas State Univeristy
Abstract Number: 75 Working Group: Aerosol Physics
Abstract Coarse mode atmospheric aerosol particles are abundant in agricultural, desert, and urban environments. The accurate characterization of these particles’ morphology is an important need in scientific and applied contexts, especially to advance our understanding for how such aerosols influence the solar radiative forcing of the atmosphere. Light scattering is the standard method used to study aerosol particles in a contact-free manner, wherein measured scattering patterns are interpreted to infer particle morphology. Due to the absence of wave-phase information in such measurements, the inference is not unique, which in part, is the essence of the inverse problem. An alternative approach is digital holography where wave-phase information is encoded in the measurements. We will show that digital holography and spatial filtering can solve the inverse problem for free-flowing particles in the sense that a measured scattering pattern can be uniquely associated with the particle size, shape, and orientation producing it. We will also show how the total cross sections are obtained as well and discuss the implementation of this work in a field instrument currently under construction.