Study Of Aerosol Number Concentration Distribution And New Paiticle Formation Events In Nanjing Northern Suburb

Based on the observation data from 2013 to 2014 by WPS,SMPS，β rays monitor.and EMS air pollution monitoring system,while this research was connected with the backward trajectory, ground meteorological elements,weather map for observation and analysis. We want to offer help for researching formation mechanism of aerosol and pollution control in Nanjing.This research shows that during June 2013 to May 2014, the average number of the nucleation mode and the Aitken mode particles concentration is 2292cm-3 and 666.cm-3. In the aerosol number spectrum distribution,it was a single peak type in spring; it were double peak type in summer,autumn and winter. In the number concentation distribution of different modal particle,the nucleation mode showed a single peak in the four seasons; the Aitken mode showed a single peak in spring and summer, it were bimodal type in autumn and winter. In the daily concentration of pollution gas: NO, and CO in four seasons were double peak type; O3 was a single peak type; SO2 were a single peak type in spring,autumn and winter. The air masses were divided into four types during the observation period: the eastern ocean air masses and the local air masses occurred in the four seasons; the northwest continental airmass mainly occurred in the spring and autumn; and the southeastern mixed air masses only in summer.In the new particle formation events,the formation rate of 7.1 ±9.5cm-3/s,the growth rate of 6.5±4.1 nm/h,the condensate sinks of 0.02±0.03s-1,the ralative humidity of 52%. The frequency of occurrence, the rate of formation and growth are the highest in summer and the lowest in winter. In the concentration spectrum of 14-165nm:it was a single peak type in spring; it were double peak type in summer,autumn and winter. The daily distribution of the nucleation mode showed a single peak in spring, summer and autumn; it was bimodal type in winter. The nucleation mode particles concentration was positively correlated with SO2 in spring,negatively correlated with O3 and NOx; it was negatively correlated with SO2 in summer and positively correlated with O3 and NOx; it was positively correlated with SO2, O3 and NOx in autumn and winter. During the NPF days, the air masses in the spring and autumn mainly came from the surrounding areas and Mongolia countries; the air masses in summer mainly came from the surrounding areas and the Pearl River Delta region; the air masses in winter mainly came from Mongolia.During the period from August 6.2014 to September 3, it was divided into five types according to the synoptic type. The aerosol number concentration of 0.01-10μm was 7302cm-3, it was the largest in type of the col circulation, ald the smallest in type of the cold anticyclone. The concentration of NOx, O3, SO2 and CO was 23.1μg/m3,55.1μg/m3, 8.7μg/m3 and 867.3μg/m3, respectively, In the number concentration spectrum, the type of the continental high atmospheric pressure was the double peak;the type of the col circulation, the cold vortex, and the subtropical high showed a single peak; the type of the cold anticyclone showed three peak.