The airborne particulate matter (PM) can cause a decrease in the atmospheric visibility. Charlson et al. (1967) found the visibility could be shown as v c L 儹 k /M , where Lv is the prevailing visibility (km), Mc is the PM concentrations (mg m-3) and k is the concentration-visibility ratio (g m-2). This study tries to establish the regression equation between particulate concentrations and atmospheric visibility at Kaohsiung, Taiwan. We used the average daily PM10 and PM2.5 concentrations including nine air quality monitoring stations around Kaohsiung and average daily visibility data at Kaohsiung weather station from 2005 to 2009. However, visibility distances can be reduced by precipitation effects. The concentrations and visibility data were screened for precipitation events. The time series plot for daily visibility, PM10 and PM2.5 from 2005 to 2009 were shown in Figure 1. PM10 and PM2.5 concentrations show negative correlation with visibility (R= -0.715 and -0.747, respectively). The results show that elevated PM concentrations impaired the atmospheric visibility. Then the data from 2005 to 2008 were applied as the regression period and the k values for PM10 and PM2.5 are obtained as 0.3577 and 0.1959 shown in Figure 2 (R= 0.742 and 0.749, respectively). Finally the regressed k values are used to calculate the daily PM concentrations in 2009 as the verification period. Figure 3 shows the plots of the observed versus calculated PM10 and PM2.5 concentrations. The correlation coefficient and absolute bias between observed and calculated PM concentrations for PM10 are 0.733 and 22.4％, similarly for PM2.5 are 0.803 and 24.4％. The calculated PM10 and PM2.5 concentrations match well with the observed data at Kaohsiung weather station in 2009.
visibility particulate matter regression equation
Chien-Lung Chen Feng-Chao Chung San-Fu Lee Li-Ying Hsieh Su-Ching Kuo Ying I.Tsai
Department of Industrial Engineering and Management,Fortune Institute of Technology,1-10,Nwongchang Department of General Education Center,Fortune Institute of Technology,1-10,Nwongchang Rd.,Daliao,Ka Department of Finance,Fortune Institute of Technology,1-10,Nwongchang Rd.,Daliao,Kaohsiung 831,Taiwa Department of Chemistry,National Cheng Kung University,1,University Rd.,Tainan 701,Taiwan Department of Medicinal Chemistry,Chia Nan University of Pharmacy and Science,60,Sec. 1,Erh-Jen Rd., Department of Environmental Engineering and Science,Chia Nan University of Pharmacy and Science,60,S