HAVO1 (Hawaii Volcanoes National Park, HI, Lat. 19.4309, Long. -155.2579, Alt. 1204)
2 years aerosol data are available in Hawaii Volcanoes National Park during the sampling period of 1997 - 2002. As shown in Figure 1, the overall average total light extinction coefficient (Bext) is 27.9 Mm-1 (Visual Range ~ 140 Km; Deciview ~ 10.3). The average PM2.5 mass concentration is 2.9 mg/m3. The average contributions of the major aerosol components to Hawaii Volcanoes National Park haze are particulate sulfate 47.2%, nitrate 3.0%, organic matter (OMC) 9.2%, elemental carbon (light absorbing carbon, LAC) 1.4%, fine soil 0.5% and coarse mass (CM) 2.8%.
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 51.3 Mm-1, which is about 11.6 times of the value of 4.4 Mm-1 during the 20% best days and 4.6 times of the value of 11.2 Mm-1 during the middle 60% days. Sulfate is the largest contributor to aerosol light extinction, with a contribution of 87% in the 20% worst days.
Figure 3 suggests that the highest occurrence of the 20% worst days happened in February, November and December, in which ~ 30% of the sampling days are the 20% haziest days at Hawaii Volcanoes National Park. As shown in Figure 4, particulate sulfate is the largest aerosol contributor to haze, with a contribution of ~ 41 - 84% during 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)
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)