REDW1 (Redwood National Park, CA, Lat. 41.56, Long. -124.0858, Alt. 245) Print-Friendly Version Print-Friendly Version (B&W)
6 years aerosol data are available in Redwood National Park during the sampling period of 1997 - 2002. As shown in Figure 1, the overall average total light extinction coefficient (Bext) is 32.8 Mm-1 (Visual Range ~ 119 Km; Deciview ~ 11.9). The average PM2.5 mass concentration is 4.5 mg/m3. The average contributions of the major aerosol components to Redwood National Park haze are particulate sulfate 31.0%, nitrate 10.9%, organic matter (OMC) 15.5%, elemental carbon (light absorbing carbon, LAC) 3.3%, fine soil 0.5% and coarse mass (CM) 8.2%.
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 47.7 Mm-1, which is about 6.9 times of the value of 6.9 Mm-1 during the 20% best days and 2.4 times of the value of 19.5 Mm-1 during the middle 60% days. Sulfate is the largest contributor to aerosol light extinction, with a contribution of 40% in the 20% worst days. OMC also contributes 29% to the aerosol light extinction in the 20% 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 Redwood National Park, and sulfate and OMC are two of the largest aerosol contributors to haze in the 20% worst days with a contributions of 37% and 26%, respectively. As shown in Figure 4, nitrate is the largest aerosol contributor to haze in the 20% worst days in January, with a contribution of ~ 31%. OMC is the largest aerosol contributor in the worst days from October to December, with a contribution of 30 - 45%. Sulfate is the largest aerosol contributor for the rest of the year, with a contribution of 30 - 50% in the 20% worst days.
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)
