학술논문

Estimates of Particle Hygroscopicity during the Southeastern Aerosol and Visibility Study.
Document Type
Article
Source
Journal of the Air & Waste Management Association (Air & Waste Management Association). May2000, Vol. 50 Issue 5, p677-685. 9p. 1 Diagram, 4 Charts, 12 Graphs.
Subject
*AEROSOLS
*WATER
*HUMIDITY
*PARTICLES
*SCATTERING (Physics)
*REFRACTIVE index
Language
ISSN
1096-2247
Abstract
Aerosol water content was determined from relative humidity controlled optical particle counter (ASASP-X) size distribution measurements made during the Southeastern Aerosol and Visibility Study (SEAVS) in the Great Smoky Mountains National Park during summer 1995. Since the scattering response function of the ASASP-X is sensitive to particle refractive index, a technique for calibrating the ASASP-X for any real refractive index was developed. A new iterative process was employed to calculate water mass concentration and wet refractive index as functions of relative humidity. Experimental water mass concentrations were compared to theoretically predicted values assuming only ammonium sulfate compounds were hygroscopic. These comparisons agreed within experimental uncertainty. Estimates of particle hygroscopicity using a rural aerosol model of refractive index as a function of relative humidity demonstrated no significant differences from those made with daily varying refractive index estimates. Although aerosol size parameters were affected by the assumed chemical composition, forming ratios of these parameters nearly canceled these effects. [ABSTRACT FROM AUTHOR]