MEVE1 (Mesa Verde National Park, CO, Lat. 37.1984, Long. -108.4906, Alt. 2177) Print-Friendly Version Print-Friendly Version (B&W)
6 years aerosol data are available in Mesa Verde National Park during the sampling period of 1997 - 2002. As shown in Figure 1, the overall average total light extinction coefficient (Bext) is 25.4 Mm-1 (Visual Range ~ 153 Km; Deciview ~ 9.3). The average PM2.5 mass concentration is 3.5 mg/m3. The average contributions of the major aerosol components to Mesa Verde National Park haze are particulate sulfate 22.1%, nitrate 4.9%, organic matter (OMC) 15.2%, elemental carbon (light absorbing carbon, LAC) 5.5%, fine soil 3.8% and coarse mass (CM) 9.2%.
Figure 1 Average contributions of major aerosol chemical components to light extinction (Based on data available in 1997-2002) (B&W)
Figure 2 Average contributions of major aerosol chemical components to light extinction in 20% best, middle 60% and 20% worst days (Based on data available in 1997-2002) (Data Table) (B&W)
As Figure 2 indicates, the average aerosol light extinction coefficient (Bext – Rayleigh Scattering (10 Mm-1)) during the 20% worst days is 27.6 Mm-1, which is about 3.7 times of the value of 7.4 Mm-1 during the 20% best days and 2.0 times of the value of 13.9 Mm-1 during the middle 60% days. Sulfate is the largest contributor to aerosol light extinction during the 20% worst days, and the contribution of sulfate to aerosol light extinction is ~ 31.8% in worst days. OMC and CM also contribute 25.7% and 19.8% in the worst days.
Figure 3 suggests that the highest occurrence of the 20% worst days happened in August, in which ~ 40% of the sampling days are the 20% haziest days at Mesa Verde National Park. As shown in Figure 4, sulfate and nitrate contribute 26.5% and 20.7% to regional haze in the 20% worst days in August. Relatively high light extinction coefficients are found in March. CM is the largest contributor to haze in March, with a contribution of ~ 50% in the 20% worst days. Fine soil also contributes ~ 13%. This suggests that the haziest days in March may be due to occasionally happened dust storm events happened at the site region.
Figure 3 Percentage of sampling days that are 20% worst days in each month (Based on data available in 1997-2002) (Data Table) (B&W)
Figure 4 Average contributions of major aerosol chemical components to light extinction during 20% worst days in each month (Based on data available in 1997-2002) (Data Table) (B&W)
