AGS-PRF: Sensitivity Analysis of Carbonaceous Aerosol Mixing State and Morphology on Spectral Optical Properties

Heinson William R, Saint Louis MO

Investigators

Abstract

Small atmospheric particles, known as aerosols, can impact weather and climate through their interaction with clouds and radiation. In this project, research will take place to determine how aerosol size, shape, and composition impacts the interaction of aerosols with radiation. This project will focus on black carbon, which is emitted from various combustion sources such as forest fires and vehicle exhaust. The main result of the project would be a quantitative estimation of the sensitivity of radiative properties to aerosol morphology and composition, which will help to improve climate model simulations. The postdoctoral researcher also plans to conduct various education and outreach activities, such as teaching a college course, mentoring undergraduate students, and providing research opportunities to high school students. The researcher plans to conduct a project to systematically understand and parameterize the sensitivity of the spectral optical properties of carbonaceous aerosols to variations in aerosol morphology, refractive index, and external mixing. The approach will be computational in nature involving the use of state-of-the-art aerosol simulation techniques and non-spherical particle-electromagnetic radiation interaction codes. Four main research questions are posed: 1) How do the physical properties of black carbon aerosol evolve as a function of organic carbon coating? 2) How do the intensive optical properties and extensive optical properties differ for bare black carbon morphology and those with external mixing with organic carbon? 3) What is the spectral response of bare and externally-mixed black carbon? 4) What corrections are needed to spherical core-shell calculations, conventionally used in climate models, with regard to incorporating non-spherical black carbon particles with and without organic carbon mixing?