HR: 0830h
AN: A31E-0096    [PDF]
TI: Solar Ultraviolet Radiation Received in an Urban Area
AU: * Winiecki, S E
EM: shelby@uchicago.edu
AF: University of Chicago, 5734 South Ellis Avenue, Chicago, IL 60637-1434 United States
AU: Frederick, J E
EM: frederic@uchicago.edu
AF: University of Chicago, 5734 South Ellis Avenue, Chicago, IL 60637-1434 United States
AB: Urban air chemistry is driven by solar UV radiation. Therefore, it is important to understand the variability in UV radiation at the ground and the physical mechanisms behind this variability. This study seeks to analyze measurements of UV spectral irradiance made by a Brewer Spectrophotometer in Chicago. The Brewer Spectrophotometer is a single-grating instrument for measuring ozone and UV research, and is operating at the University of Chicago as part of the USEPA UV monitoring network. Instrumental measurements are benchmarked to a radiative transfer model under clear sky conditions over the air pollution season. Comparisons between measured irradiances and calculations based on column ozone obtained from satellite-based sensors, allow an interpretation of observed variability in terms of cause and effect. In addition, spectral weightings are applied to measurements and model results based on dissociation cross sections of NO$_2$ and O$_3$. This produces quantities that are useful indicators of the UV radiation that drives air chemistry.
DE: 0345 Pollution--urban and regional (0305)
DE: 3359 Radiative processes
SC: Atmospheric Sciences [A]
MN: 2003 Fall Meeting