Member Price:
$5.00
Nonmember Price:
$15.00
|
Your Price: $15.00
Order Code:
Add to Cart |
The Midwest has two federal Class 1 areas, located on the far northern edge of the region.
Compared to the western and eastern United States, only limited visibility data have been
collected to date in the Midwest. As part of the Midwest Regional Planning
Organization’s efforts to assess the nature, origins and transport of haze in the region,
speciated fine particle data from the midwestern and eastern IMPROVE sites, as well as
the eight CASTNET sites that collect visibility data, were analyzed for the 1997-1999
period. Extinction coefficients were calculated from reconstructed fine mass using
monthly average relative humidities. Spatial and seasonal variations based on these
reconstructed light extinction coefficients were examined for the 20% best and worst
days, and show that the Midwest, especially in its far northern reaches, exhibits quite
different seasonal and particle composition patterns than the eastern states. Trajectory
analysis of all sample days was conducted using the HYSPLIT model to map 48-hour
backward trajectories at each site. The resulting ‘families’ of trajectories for each site
were used to construct contours that reveal the probability of poor (or good) air quality at
the monitor when the air passes over a particular area upwind. These contours were then
normalized to remove the underlying wind frequency distribution, and the resulting
surfaces (source contribution functions) are compared to emission source information to
assess their usefulness in identifying potential source regions
|
CNumber:
Regional Haze and Global Radiation 10/02/2001
|
|
Publication Type:
Proceedings
|
|
Publication Date:
October 2001
|
|
|
|
