Haze Observation And Particulate Matter Concentration Inversion With Lidar In Nanjing

Current research about haze which has been focused on the analysis of weather situation,chemistry component, pollution source and so on.The research on haze of profile pollution characteristics and effect of Atmospheric Boundary Layer Height(ABLH) has still rarely been researched.In addition,the current method of estimating surface particulate matter utilizes satellite data.However,the main method has deficiency.Lidar could obtain profile aerosol signal so that we find out a new method to obtain aerosol profile extinction coefficient,ABLH and surface PM.At first,we have been researched contents of two aspect in this article. A haze event in Nanjing was measured with Micro Pulse Lidar(MPL).secondly,putting forward a method base on Lidar and satellite data to simulate PM-concentrations.Firstly, a haze event in Nanjing during October2012was intensively measured with Micro Pulse Lidar(MPL). By combining the MPL-measurements with the observations of meteorology, PM10and PM2.5, we analyzed the variations of PM-concentrations, meteorological elements, vertical aerosol profiles with the optical property and mixing layer height (ABLH) and their relations.The differences of extinction coefficients and ABLH between the haze event and the non-haze period of November11-12,2012were also comapared.The analysis show that the diurnal changes of PM-concentrations and extinction coefficients were in the relatively similar pattern with the high values in night and the low values in afternoon during the haze event. Compared to the non-haze period, the ABLH was much lower, and the extinction coefficients were much higher during the haze event. The diurnal variation of ABLH lagged a little behind the air temperature. There was a negative correlation between ABLH and PM2.5during the haze event. The low and high ABLH-values respectively corresponded to the high and low extinction coefficients, respectively. We also filtrated the Lidar data and Atmospheric Optical Depth (AOD) of MODIS from April to November,2011,put forward a method to estimate PM-concentrations base on vertical aerosol extinction profiles by MPL and AOD from MODIS,then used the method compare to the method by AOD/ABLH.Finally, compared the estimated PM-concentrations with measured value.The results show,compared to the method by AOD/ABLH,the result of estimate PM-concentrations by new method was better. Correlation coefficient between surface extinction by new method with measured PM2.5and PM10concentrations is0.8and0.62respectively, compared the estimated PM-concentrations by the two kind of methods with measured value, degree of accuracy of the new method is better.