| Abstract: | In order to reveal the diurnal and seasonal variations in particulate mass concentration( PM1,PM2. 5,and PM10) during the heavy haze periods and non-haze periods,the statistics based on the data from the Shanghai Urban Environmental Meteorological Center from December 2008 to November 2010 were analyzed. The results were shown as follows. The particulate matter and black carbon( BC) concentrations,especially the fine particulate matter concentrations during the heavy haze were significantly higher than that during the non-haze periods. Overall,the averaged proportion of PM2. 5to PM10 accounted for 59% during the non-haze periods and 81% during the heavy haze periods while that of PM1 to PM10accounted for 43% for the non-haze periods and 70% for the heavy haze periods. Particulate matter concentration had two peaks at11: 00 and 17: 00 in a day. The aerosols concentrations were the highest while the seasonal variation of visibility was the lowest in winter,followed successively by spring,autumn,and summer. |
