A119 Atmospheric visibility model

Mathematical models for accurate prediction of atmospheric visibility with particular reference to the seasonal and environmental patterns in Hong Kong

Brief:

This study analyzed the atmospheric visibility data measured in urban and suburban Hong Kong (two selected stations) with respect to time-matched mass concentrations of common air pollutants including nitrogen dioxide (NO₂), nitrogen monoxide (NO), respirable suspended particulates (PM₁₀), sulphur dioxide (SO₂), carbon monoxide (CO) and meteorological parameters including air temperature, relative humidity and wind speed. No significant difference in atmospheric visibility was reported between the two measurement locations (p≥0.6, t-test); and good atmospheric visibility was observed more frequently in summer and autumn than in winter and spring (p<0.01, t-test). It was also found that atmospheric visibility increased with temperature but decreased with the concentrations of SO₂, CO, PM₁₀, NO and NO₂. The results showed that atmospheric visibility was season dependent and would have significant correlations with temperature, the mass concentrations of PM₁₀ and NO₂, and the air pollution index API (correlation coefficients |R|³0.7, p≤0.0001, t-test). Mathematical expressions catering to the seasonal variations of atmospheric visibility were thus proposed.

This work forms part of an undergraduate final year project. Student: L.Y. Chung (BEng)

Further information:

Mui KW, Wong LT, Chung LY, 2009. Mathematical models for accurate prediction of atmospheric visibility with particular reference to the seasonal and environmental patterns in Hong Kong, Environmental Monitoring and Assessment 158(1-4) 333-341.