GUMO1 (Guadalupe Mountains National Park, TX, Lat. 31.833, Long. -104.8094, Alt. 1674)

6 years aerosol data are available in Guadalupe Mountains National Park during the sampling period of 1997 - 2002. As shown in Figure 1, the overall average total light extinction coefficient (Bext) is 35.7 Mm-1 (Visual Range ~  109 Km; Deciview ~ 12.7). The average PM2.5 mass concentration is 5.6 mg/m3. The average contributions of the major aerosol components to Guadalupe Mountains National Park haze are particulate sulfate 30.4%, nitrate 5.8%, organic matter (OMC) 11.0%, elemental carbon (light absorbing carbon, LAC) 3.7%, fine soil 4.7% and coarse mass (CM) 16.5%. 

Bext = 35.7 Mm-1

Figure 1 Average contributions of major aerosol chemical components to light extinction (Based on data available in 1997-2002)

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)

As Figure 2 indicates, the average aerosol light extinction coefficient (Bext – Rayleigh Scattering (10 Mm-1)) during the 20% worst days is 46.0 Mm-1, which is about 4.3 times of the value of 10.8 Mm-1 during the 20% best days and 1.9 times of the value of 23.7 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  ~ 44.1% in worst days. CM also contributes 24% to aerosol light extinction.

Figure 3 suggests that the highest occurrence of the 20% worst days happened in September, in which ~40% of the sampling days are the 20% haziest days at Guadalupe Mountains National Park. As shown in Figure 4, Sulfate is the largest aerosol contributor to haze in the summer, with a contribution of 40-55% in the 20% worst days. In the spring, CM is the largest aerosol contributor to haze, and its contribution is about 30% in the worst days. Fine soil also contributes ~25% during the 20% worst days in March, which may due to relatively long-range transported dust.

Figure 3 Percentage of sampling days that are 20% worst days in each month (Based on data available in 1997-2002)

 

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)