Observations Of Boundary Layer Aerosol Over Northern Suburb Of Nanjing By Multifunction Lidar

The paper presented the aerosol measurement by Micro-Pulse Lidar (MPL) system and Rayleigh-Raman-Mie-Lidar (RRML) system in Nanjing Comprehensive Observation Base of China Meteorological Administration in the north suburb of Nanjing. Introduced two Lidars instruments parameters and detection principle,and two Lidars echo data was corrected.Using Fernald inversion analysis method to obtained aerosol extinction coefficient and thus calculate the mixing layer height and aerosol optical thickness.The results show that aerosol extinction coefficient is on the order at 10-1km-1, and the height of mixing layer is calculated based on the extinction coefficient,statistical results obtained the height of mixing layer range from 1 km to 1.5 km, and change over time.The variation of aerosol extinction coefficient profiles and depolarization ratio profiles by MMPL indicated that the depolarization ratio of aerosols in clear atmosphere, mist and water cloud have similar values,but the value of ice cloud depolarization ratio is larger than all of them.Nearly 50 times inversion results of experimental data during January to June in 2009 show that the depolarization ratio is concentrated between 0 to 0.05 when the height of cloud base below 4 km. While the height above 4 km, this value is almost between 0.05 to 0.15. The higher of height cloud base is, the higher of the probability of larger depolarization ratio values is appeared.monitoring once strong winter dust and analysing the extinction coefficient and depolarization ratio temporal variation, while analysing the atmospheric clouds qualitative dynamic.Monitored once the summer fog aerosol extinction coefficient (mean of 2.23 km-1) bigger than mist aerosol extinction coefficient (mean of 0.7 km-1) and aerosol extinction coefficient after dissipated fog (mean of 0.17 km-1);Mist internal structure clearer, and the dissipate height boundary changes dramatically over time,the fog blurred boundaries and boundary extinction coefficient decreases with height to the sky background aerosol extinction coefficient values rather;During strong dust period,dust aerosol extinction coefficient of up to 3 km-1, corresponding depolarization ratio is great, the values is between 0.6 and 0.8,and the remaining time aerosol extinction coefficient is great, but the depolarization ratio of 0.2 to 0.5 during weak dust period,dust extinction coefficient mean of 0.26 km-1.Dust influence height of about 1 km, up to 1.5 km; Comparing the inversion results of summer mist and winter dust in 2012,the results show that dust appears obvious boundary, while the characteristics of mist boundary is blurred.Dust’s outbreak and dissipate can be monitored by combining spatial distribution and temporal distribution of extinction coefficient with change of depolarization ratio.Comparing the results of MMPL and CE-318 sun photometer, the optical thickness of both instruments measured is consistent with the trends of time.