Characterization of a Rural Elemental Carbon Aerosol and its Resulting Radiative ForcingEPA Grant Number: U914733
Title: Characterization of a Rural Elemental Carbon Aerosol and its Resulting Radiative Forcing
Investigators: Dillner, Ann
Institution: University of Illinois at Urbana-Champaign
EPA Project Officer: Chung, Serena
Project Period: January 1, 1995 through January 1, 1996
Project Amount: $102,000
RFA: STAR Graduate Fellowships (1995) Recipients Lists
Research Category: Academic Fellowships , Engineering and Environmental Chemistry , Fellowship - Engineering
The main objectives of this research project are to: (1) measure the phase function and asymmetry factor for single-ice crystals; (2) measure the scattering and extinction coefficients, the single-scattering albedo, the phase function, and the asymmetry parameter for a monodisperse population of ice crystals; (3) compare measured parameters to data sets collected in field studies; and (4) propose parameterization of radiative properties for inclusion in cloud and climate models.
Cirrus clouds have a significant impact on climate due to their influence on radiative transfer through the atmosphere and their pervasiveness around the globe. Climate models require accurate representations of cirrus clouds to effectively predict global climate. In this research, single crystals will be studied using an electrodynamic balance, which suspends a charged ice crystal against the force of gravity using electric fields. An array of detectors will be used to measure the phase function around the crystal. An optical chamber will be used to measure scattering and extinction coefficients and the phase function of a cloud or population of monodisperse ice crystals.