PINN1 (Pinnacles National Monument, CA, Lat. 36.485, Long. -121.1555, Alt. 317) Print-Friendly Version Print-Friendly Version (B&W)
6 years aerosol data are available in Pinnacles National Monument during the sampling period of 1997 - 2002. As shown in Figure 1, the overall average total light extinction coefficient (Bext) is 42.0 Mm-1 (Visual Range ~ 93 Km; Deciview ~ 14.4). The average PM2.5 mass concentration is 5.3 mg/m3. The average contributions of the major aerosol components to Pinnacles National Monument haze are particulate sulfate 23.5%, nitrate 18.5%, organic matter (OMC) 16.7%, elemental carbon (light absorbing carbon, LAC) 7.4%, fine soil 1.1% and coarse mass (CM) 9.0%.
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 54.3 Mm-1, which is about 3.9 times of the value of 13.8 Mm-1 during the 20% best days and 1.8 times of the value of 30.4 Mm-1 during the middle 60% days. Sulfate, nitrate and OMC each contributes about 20-30% to aerosol light extinction in the 20% worst days.
Figure 3 suggests that the highest occurrence of the 20% worst days happened in March, in which ~ 40% of the sampling days are the 20% haziest days at Pinnacles National Monument. As shown in Figure 4, nitrate is the largest aerosol contributor to haze in the 20% worst days in the Winter time, with a contribution of ~ 40%. While sulfate is the largest aerosol contributor, with a contribution of 25-30%, to haze from March to October except August. OMC is important in the summer, and dominates in August.
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)
