Abstract |
The reduction in visual range in the eastern U.S. is caused largely by sulfate particles. Therefore, it is expected that the spatial distribution and temporal trend of man-made haziness will, to some extent, correspond to the spatial-temporal pattern of sulfur emissions. The purpose of the study is to examine the sulfur emission-haze relationship using regionally and seasonally disaggregated SO(2) emissions and visual range data. Across much of the Northeast the wintertime haziness has been either declining or slightly increasing over the past three decades. The summertime haziness has been generally increasing in all areas of the eastern U.S. The monthly sulfur emissions for individual states were reconstructed using yearly emission trends and seasonal emission rates. Before 1970 winter emissions were greater but since the 1970's the summer emissions have become comparable in magnitude. These relationships may be used as a first indication of how visibility might change with changes in SO(2) emissions. |