The Study of PM10, PM2.5 Mass Extinction Efficiency Characteristics Using LIDAR Data

From 2015 to June 2020, the backscattering coefficients of 532 and 1064 nm measured using LIDAR and the depolarization ratio at 532 nm were used to separate the backscattering coefficient at 532 nm as three types as PM10, PM2.5-10, PM2.5 according to particle size. The mass extinction efficiency (MEE) of three types was calculated using the mass concentration measured on the ground. The overall mean values of the calculated MEE were 5.1 +/- 25, 1.7 +/- 3.7, and 9.3 +/- 6.3 m(2)/g in PM10, PM2.5-10, and PM2.5, respectively. When the mass concentration of PM10 and PM2.5 was low, higher than average MEE was calculated, and it was confirmed that the MEE decreased as the mass concentration increased. When the MEE was calculated for each type according to the mixing degree of Asian dust, PM2.5-10 was twice at pollution aerosol as high as 2.1 +/- 2.8 m(2)/g, compare to pollution-dominated mixture, dust-dominated mixture, and pure dust of 1.1 +/- 1.8,1.4 +/- 3.3,1.1 +/- 15 m(2)/g, respectively. However, PM2.5 MEE showed similar values irrespective of type: 9.4 +/- 65,9.0 +/- 5.8, 103 +/- 7.5, and 9.1 +/- 9.0 m(2)/g. The MEE of PM10 was 5.6 +/- 2.9, 4.4 +/- 2.0, 3.6 +/- 2.9, and 2.8 +/- 24 m(2)/g in pollution aerosol (PA), pollution-dominated mixture (PDM), dust-dominated mixture (DDM), and pure dust (PD), respectively, and increased as the dust ratio value decreased. Even if the same type according to the same mass concentration or Asian dust mixture was shown, as the PM2.5/PM10 ratio decreased, the MEE of PM2.5-10 decreased and the MEE of PM2.5 showed a tendency to increase.