Daytime Variation of PM2.5 Concentration in Street Canyons on Weak-Wind Summer Days
Daytime variations of PM2.5 concentration in three street canyons in Xi’an were measured during June 11-15, 2010. Weather conditions, including ambient wind condition and street canyon air temperature were recorded as well. These measurement were conducted under weak-wind summer days, when the mean ambient wind velocity was 1.26 m/s. The measurement results showed that, under weak-wind conditions, PM2.5 concentrations and vehicle flux inside the street canyons did not have good correlation. PM2.5 concentrations accumulated inside the street canyons in daytime with near uniform horizontal distribution at the pedestrian level. These results indicated the absence of the typical primary air flow re-circulation inside the street canyons under the weak-wind conditions, and the dispersion and transportation of the vehicle exhausts inside and out of the street canyons were influenced by vehicle induced air flow and thermal induced buoyancy.
PM2.5 concentration Weak-wind condition Street canyon Xi’an
Yun-Wei Zhang Zhao-Lin Gu Yan Cheng Zhen-Xing Shen Jun-Gang Dong Shun-Cheng Lee
School of Energy and Power Engineering,Xian Jiaotong University,Xian,710049 Department of Environmental Science and Technology,School of Human Settlements and Civil Engineering Architecture and Technology Department,Xian University of Architecture and Technology,Xian,710055 Department of Civil and Structural Engineering,The Hong Kong Polytechnic University,Hung Hom,Kowloon
国际会议
西安
英文
1197-1204
2011-08-17（万方平台首次上网日期，不代表论文的发表时间）