The Applications Particulate Li DAR in the Stereo-Monitoring for the Complex Atmospheric Pollution
To analyze the three different mechanisms for the haze formation respectively caused by local pollutants,dust sunk,and the superposition with local pollution diffusion and exogenous pollution input,we applied particulate Li DAR to detect the spatial and temporal characteristics of suspended particulate matter in three different examples. In the haze episodes resulting mainly from the local pollutions,the particulate matter always spread from the ground level to about 1 km. The daily-averaged aerosol profile violated the exponential function,especially in severe pollution days. The extinction coefficient was nearly a constant of0. 3 km- 1below 800 m. A layer with a maximum of extinction coefficient in the aerosol profile was shown at about 800 m,which was over 1 km- 1. Such layer weakened the vertical dispersion of pollution contributing a primary factor for a wide visual range obstacle. For the haze pollution caused by dust mass input,Li DAR clearly outlined the dust profile varied in altitudes. The dust masses always suddenly occurred in 2- 3 km with a depolarization coefficient over 0. 3. It expanded in vertical direction due to the dust's gravitational settlement,which raising the concentration of coarse particulate matter( PM10) greatly larger than that of fine particle matter( PM2. 5). In the third example,Li DAR mapped an input pollution mass floating in 1. 8- 3 km which containing mainly of fine particles. This input pollution felled into the atmospheric boundary layer( ABL) at noon mixing with the pollution diffused to 1. 8 km from ground level,which eventually caused the local haze pollution. In conclusion,we found theLi DAR system could effectively describe the space-time distribution of particulate pollutants. It was advantage to explain three different mechanisms of haze-formation. As one kind of remote sensing techniques,Li DAR could be applied to study the atmospheric complex pollution.