LOST1 (Lostwood, ND, Lat. 48.642, Long. -102.4021, Alt. 692) Print-Friendly Version Print-Friendly Version (B&W)
3 years aerosol data are available in Lostwood during the sampling period of 1997 - 2002. As shown in Figure 1, the overall average total light extinction coefficient (Bext) is 42.7 Mm-1 (Visual Range ~ 91 Km; Deciview ~ 14.5). The average PM2.5 mass concentration is 4.9 mg/m3. The average contributions of the major aerosol components to Lostwood haze are particulate sulfate 29.1%, nitrate 20.0%, organic matter (OMC) 13.2%, elemental carbon (light absorbing carbon, LAC) 3.9%, fine soil 1.5% and coarse mass (CM) 8.9%.
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 62.4 Mm-1, which is about 4.8 times of the value of 13.0 Mm-1 during the 20% best days and 2.2 times of the value of 28.8 Mm-1 during the middle 60% days. Nitrate and sulfate are two of the largest contributors to aerosol light extinction during the 20% worst days, and the contributions of nitrate and sulfate to aerosol light extinction are ~ 36.7% and 35.8% in worst days.
Figure 3 suggests that the highest occurrence of the 20% worst days happened in the cold season, in which ~ 30 - 40% of the sampling days are the 20% haziest days at Lostwood. As shown in Figure 4, during the month of January to March and November to December, both nitrate and sulfate contribute ~ 30 - 45% to regional haze 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)
