Record Display for the EPA National Library Catalog


Main Title On the Proportionality of Fine Mass Concentration and Extinction Coefficient for Bimodal Size Distributions.
Author Lewis, Charles W. ;
CORP Author Environmental Sciences Research Lab., Research Triangle Park, NC.
Year Published 1981
Report Number EPA-600/J-81-125;
Stock Number PB82-207770
Additional Subjects Light transmission ; Aerosols ; Particle size ; Light scattering ; Concentration(Composition) ; Arid land ; Visibility ; Air pollution ; Reprints ; Air quality ; Extinction coefficients ; Atmospheric transmissivity
Library Call Number Additional Info Location Last
NTIS  PB82-207770 Some EPA libraries have a fiche copy filed under the call number shown. 07/26/2022
Collation 10p
For a bimodal size distribution of ambient aerosol, an upper limit in particle size can be chosen for the fine aerosol fraction so that the extinction coefficient for light scattering and absorption is directly proportional to the fine mass concentration, with no dependence on the coarse mass concentration. With the size parameters of the modes taken to be 'grand average continental' values of Whitby, the upper size limit is 3.4 micrometers (aerodynamic diameter). Consequently, the extinction coefficient could be inferred from a measurement of the fine mass concentration only, even in arid regions where coarse aerosol concentrations usually far exceed the fine.