Black carbon variation during a high pollution haze episode in Beijing, China
Black carbon (BC) aerosol is esthetically displeasing as it is responsible for the brown appearance of urban hazes.In this study,atmospheric BC aerosol was measured using an aethalometer (AE-31) at an urban location of Haidian District,Beijing from May 2012 to March 2013.A logarithmic negative correlation (R2=0.5120) between BC and visibility suggested that BC was an important air pollution factor to affect air quality in Beijing.BC concentration showed significant seasonal variation with mean concentration varying between 4.24 μg m-3(summer) to 8.14μg m-3 (winter).The highest daily mean concentration was recorded as high as 27.69 μg m-3.The highest concentration of BC occurred during a high pollution haze episode in winter.In a clear day,BC exhibited a distinct diurnal pattern,with three maximum peaks within a day.However,BC exhibited a multi–peak diurnal pattern during haze episodes from Dec 2012 to Jan 2013.Statistical factors analysis demonstrated that emission source factors were not increased,leading to multi-peak diurnal pattern in BC variation.Additionally,Weather Research and Forecasting Model showed that the boundary layer height during haze episodes hourly varied in a similar trend with normal days.All the evidence indicated that BC exhibited a rather higgledy-piggledy diurnal pattern during haze episodes,which played a key role in the stabilization of haze formation.
Black carbon aerosol Haze formation Diurnal pattern Seasonal trend.
Qingyang Liu Yanju Liu Yi Gao Meigen Zhang Renjian Zhang Hui Ding Xuekui Qi
Beijing Center for Physical and Chemical Analysis, Beijing, 100089, China;College of Resources and E Beijing Center for Physical and Chemical Analysis, Beijing, 100089, China;Beijing Milu Ecological Re State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry,Institute of At Beijing Academy of Sciences and Technology, Beijing, 100089, China Beijing Center for Physical and Chemical Analysis, Beijing, 100089, China
国内会议
武汉
英文
621-638
2013-05-16（万方平台首次上网日期，不代表论文的发表时间）