Research Of Spatiotemporal Dynamics Of Aerosol Intypical Areas Of Zhejiang

Zhejiang Province is one of the faster increase places in the aerosol area,as well as an eastern coastal important economic core area,and cultural center.With the rapid economic development,population in northern Zhejiang and motor vehicles have increased dramatically,and then more serious environmental problems have occurred,resulted in respirable particulate matter having become the primary air pollutants in the region,whichis an important part of the aerosol.Sources of aerosol particles in the atmosphere are wide and complex,so research on sources and characteristics of atmospheric aerosol in this region as important practical significance for scientific forecasting and air particulate pollution controlling effectively of northern ZhejiangIn this paper,atmospheric aerosol was observed and studied for the demand of air pollution monitoring and environmental control in Zhejiang Province.And the French CEMEL manufactured automatic tracking scanning sun photometer CE-318 was used to obtain the aerosol data during 2014²015innorthern Zhejiang.Meanwhile,combined with the MODIS remote sensing data and the National Oceanic and Atmospheric Administration?NOAA?meteorological data,we analyzed the correlation between pollutant sources and its haze event by backward trajectory analysis.The main findings included:?1?In this area,in addition to annual AOT of two stands on Tianmu Mountain were less than 0.2,AOT in other monitoring sites,Hangzhou,Lin'an and Ningbo were higher than 0.2.Especially Hangzhou was the most polluted,the AOT in the year was higher than 0.7,which was heavily polluted.The AOT seasonal variation at Hangzhou station was summer> autumn> spring> winter,Lin'an was summer> spring> autumn> winter and Ningbo Station was spring> winter> autumn> summer.Among these three stations,Ningbo had significant seasonal variation.The AOT of two sites on Tianmu Mountain had no significant seasonal variation because of good vegetation cover,which was characterized by seasonal variation spring> autumn> winter> summer on the topof Tianmu Mountain and spring> summer> winter> autumn at the foot of Tianmu Mountain.?2?PM_2.5 mass concentration results showed that,the highest of monthly average PM_2.5 in Hangzhou,Lin'an,Ningbo appeared in winter.And the spatial distribution of particulate matter hadobvious geographical characteristic.Thatwas,PM_2.5 in Lin'an was the most,Hangzhou followed and Ningbo was the lowest due to the sea breeze and the greater impact of exogenous transmission.?3?The analysis of AOT and diurnal variation of PM_2.5 in Hangzhou showed that,time variation of aerosols in this area was obvious.Under the premise of stable atmosphere and atmospheric pollutants mainly were local emissions,the change trends of PM_2.5 and the AOT concentration showed a good consistency.Besides,the relationship between change of PM_2.5 and the size of urban transport was closed and the AOT was influenced greatly by particles transmitting,but both of them were affected by meteorological factors and land cover types.?4?In northern Zhejiang Province,during the four haze occurred,the correlation of AOT with PM_2.5 mass concentration was good.There was significant difference in the P <0.01 level,with high statistical significance.