GACP Projects
Modeled Aerosol Optical Properties from Measurement-Based Mixtures of Chemical Species-Assessing the Impacts of Particle Morphology and Absorption
Kirk A. Fuller, PI
Daniel W. Mackowski, Co-PI
Sonia M. Kreidenweis, Co-PI
Abstract: The research proposed here addresses the need for studies of radiative properties of mixed-composition aerosols, constrained by field observations, with a focus on the role of absorbing and nonspherical components. We have assembled a team of researchers with skills uniquely suited to the tasks at hand. Specifically, we will perform modeling studies that are guided by field measurements of size-resolved chemical speciation, hygroscopicity, dry aerosol size distributions, and aerosol scattering and absorption properties, from the summertime SouthEastern Aerosol and Visibility Study (SEAVS), in which one of us (SMK) participated as a principal investigator. We will extend this work using aerosol data from the IMPROVE (Interagency Monitoring of Protected Visual Environments) network, with which we have worked in the past. A radiative model that can accurately represent the effects of externally and internally mixed soot and of light absorbing mineral components of the aerosol will be completed, and will be used to test the effects of the mixing assumptions for absorbing and nonabsorbing species. By comparison with field data, we hope to be able to recommend appropriate treatments of the radiative properties of such mixtures under various conditions. As a step toward constraining uncertainties in radiative forcing and sensitivities of satellite-based retrievals, we will use the optical models to explore changes in column forcing and clear-sky reflectances with measured changes in aerosol composition and ambient conditions.
