Lidar Measurement of Aerosol, Ozone and Clouds in Beijing

摘要

Three lidar systems are developed in Institute of Atmospheric Physics. A four-wavelength lidar is used to detect ozone, aerosol and clouds, which contains a XeCl excimer laser with output energy of about 120mJ at 308nm, a Nd:YAG laser with three operating wavelengths of 355nm, 532nm and 1064nm, and a 1m-receiver telescope. A two-wavelength mobile lidar system is used to detect aerosol in troposphere and Asian dust storm, which has a Nd:YAG laser with wavelengths of 532 and 1064nm. A 1064nm Nd:YAG lidar is used to monitor city aerosol pollution. Since January 2000 the lidar systems have been used in measuring dust storm, high cloud and ground-35km aerosol extinction coefficient profiles. Measurement results show that the aerosol optical depth between 6km and 11km has a mean value of 0.0192; the cloud optical depth between 6km and 11km ranges from 0.014 to 0.23. The aerosol extinction near above the ground changes very greatly. From measurements, the change characteristics of aerosol extinction through snow and rain course, and dust storm are analyzed. Routine city aerosol pollution monitoring result is presented. The results of measurements of ozone shows that during September-October, the maximum ozone concentration is usually in the height range from 25km to 29km, and there is usually second concentration peak in the range between 10km and 17km. The compares of lidar-detected ozone profile made during 20:40-21:35 of October 16, 2001 with balloon measurement during 15:00-16:00 of same day is given.