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Extramural Research

Grantee Research Project Results

Grantee Research Project Results

Characterization of a Rural Elemental Carbon Aerosol and its Resulting Radiative Forcing

EPA 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: Broadway, Virginia
Project Period: January 1, 1995 through January 1, 1996
Project Amount: $102,000
RFA: STAR Graduate Fellowships (1995)
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.

Supplemental Keywords:

fellowship, climate, cloud model, climate model, ice crystals., RFA, Scientific Discipline, Air, Ecosystem Protection/Environmental Exposure & Risk, particulate matter, air toxics, Environmental Chemistry, Monitoring/Modeling, Analytical Chemistry, Environmental Engineering, environmental monitoring, atmospheric dispersion models, particulate organic carbon, atmospheric particulate matter, atmospheric measurements, chemical characteristics, aerosol particles, air quality models, airborne particulate matter, air sampling, carbon particles, air quality model, albedo, ultrafine particulate matter, particulate matter mass, modeling studies, climate model, aerosol analyzers, chemical speciation sampling, measurement methods, particle size measurement

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The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.

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