Measurements of Optical Properties of Particulates in an Arid Region.
Abstract
Aerosol extinction profiles and aerosol extinction-to-back-scatter ratio, S(a), values have been determined for numerous days over the period May, 1979 to May, 1982 in Tucson, AZ via slant-path lidar measurements. These results have been analyzed to obtain a model aerosol extinction profile and a model S(a) value. The model extinction profile is characterized by rapidly, nearly linearly decreasing extinction through a 3km mixing layer (decreasing from 0.018/km at 200 m to 0.003/km at 3km), and a much more slowly decreasing extinction above the mixing layer. The mixing layer optical depth is about 0.04, and the optical depth to the maximum observation height (19km) is about 0.07. The inverse variance weighted S(a) value is about 25, and the majority of the S(a) determinations fell between 20 and 35. A limited number of cooperative lidar and balloon-borne cascade impactor measurements were also made to investigate aerosol size distribution and refractive index properties and their effects on the lidar observations. Impactor measurements yielded size distributions that were generally similar in shape, the distributions being perturbed Junge types with a dominance of coarse mode particles causing a bulge in the distributions in the large particle range.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 31, 1983
- Accession Number
- ADA132889
Entities
People
- John A. Reagan
Organizations
- University of Arizona