Study on Number Concentration Distribution of Atmospheric Ultrafine Particles in Hangzhou
杭州市大气超细颗粒数浓度谱季节性特征

Atmospheric ultrafine particles(UFPs) were measured with fast mobility particle sizer(FMPS) in Hangzhou, during March 2011 to February 2012. The number concentration and size distribution of UFPs associated with meteorology were studied. The results showed that the number concentration of UFPs was logarithmic bi-modal distribution, and the seasonal levels presented winter>summer>spring>autumn. The highest monthly average concentration was 3.56×104 cm-3 in December and the lowest was 2.51×104 cm-3 in October. The seasonal values of count medium diameter(CMD) were spring>winter>autumn>summer. The highest monthly average CMD was 53.51 nm in April and the lowest was 16.68 nm in June. Meteorological factors had effects on concentration of UFPs.