|
| |
|
|
| Northern Cheyenne
Tribe |
|
| Chemical components
responsible for haze |
|
|
At the Northern Cheyenne tribal site, the average PM2.5 mass
concentration during 6/2002-8/2003 is 3.8 mg/m3,
and the average total light extinction coefficient (Bext) is 29 Mm-1
(Visual Range ~ 136 Km; Deciview ~ 11). OMC and sulfate are two of the largest
contributors to haze, with an average contribution of 22% and 21%, respectively. |
|
 |
|
Figure 1. Average
contributions of major aerosol chemical components to light extinction
|
|
|
Figure 2 suggests that, in 2003, the highest occurrence
of the 20% worst days happened in July and August, in which ~55% of the
sampling days are the 20% haziest days at Northern Cheyenne. OMC, which is
most likely from forest fires, contributes more than 50% to light extinction
in the 20% worst days during the summer of 2003. Sulfate has a relatively
constant and important contribution to haze all-around the year. |
|
 |
| Figure 2 Percentage of sampling days that
are 20% worst days in each month |
|
 |
| Figure 4 Average contributions of major
aerosol chemical components to light extinction during 20% worst days in each
month |
|
| For a detailed examination of
the aerosol characteristics at the Northern Cheyenne site consult the
aerosol description web page. |
|
|
Last updated 7 June 2005
|
