CAPI1 (Capitol Reef, UT, Lat. 38.4587, Long. -109.8209, Alt. 1799) Print-Friendly Version Print-Friendly Version (B&W)
2 and a half years aerosol data are available in Capitol Reef during the sampling period of 1997 - 2002. As shown in Figure 1, the overall average total light extinction coefficient (Bext) is 24.3 Mm-1 (Visual Range ~ 161 Km; Deciview ~ 8.9). The average PM2.5 mass concentration is 3.2 mg/m3. The average light extinction coefficient is relatively low, with ~40% of the light extinction is due to rayleigh gas scattering. The average contributions of the major aerosol components to Capitol Reef haze are particulate sulfate 17.5%, nitrate 7.4%, organic matter (OMC) 14.6%, elemental carbon (light absorbing carbon, LAC) 4.8%, fine soil 3.3% and coarse mass (CM) 11.2%.
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 25.4 Mm-1, which is about 3.6 times of the value of 7.0 Mm-1 during the 20% best days and 2.0 times of the value of 12.8 Mm-1 during the middle 60% days. OMC is the largest contributor to aerosol light extinction during the 20% worst days, and the contribution of OMC to aerosol light extinction is ~ 29.6% in worst days. Sulfate and CM also contribute ~ 24.1% and ~ 19.3% to aerosol light extinction during the worst days.
Figure 3 suggests that the highest occurrence of the 20% worst days happened in July and August, in which ~50% of the sampling days are the 20% haziest days at Capitol Reef. As shown in Figure 4, OMC is the largest aerosol contributor to haze in July and August. Nitrate dominates the aerosol light extinction in November and December, and sulfate dominates in September and October. Sulfate, OMC and CM (including fine soil in April) are almost equally important in the Spring.
Figure 3 Percentage of sampling days that are 20% worst days in each month (Based on data available 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 1997-2002) (Data Table) (B&W)
