It is currently unknown whether mineral dust aerosol particles cause a net warming or cooling effect on the climate system. Cavity Ring-Down Spectroscopy (CRDS) and Transmission Electron Microscopy have been used to measure extinction cross sections and morphologies of aerosol particles. Spherical Mie scattering theory and the Discrete Dipole Approximation have been used to compare the measured shape of size-selected aerosol particles to the observed optical properties for both nearly spherical particles of ammonium sulfate as well as irregularly shaped calcium salts. We have found that microscopy is essential for characterizing the size selection of non-spherical particles. Through the combined use of CRDS, microscopy, and computation, we have determined the effect of shape on the optical properties of calcium salts. This characterization has the potential to lead to better models of aerosol optical properties with application to climate models and satellite retrieval algorithms.

Effect of shape on the radiative properties of mineral dust aerosol particles

244th National Meeting (2012)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.