To understand the sources and pollution characteristics of black carbon (BC) aerosols in metropolitan areas

the mass concentration and meteorological parameters of BC

PM2.5

and other pollutants in Shanghai urban areas in 2014 were experimentally studied. Relevant parameters were obtained to evaluate BC pollution characteristics

source distribution

and effects on atmospheric extinction in Shanghai urban area. Results show that the mass concentration of BC had typical diurnal double-peak variations

and the annual average value reached (3.11±2.40) μg/m3. The mass concentration of BC also showed an obvious seasonal variation trend that the value was high in winter ((3.82±3.32) μg/m3) and low in summer ((2.56±1.37) μg/m3). In addition

it had a good correlation with PM2.5

and the ratio of BC/PM2.5was the highest in autumn (7.37%). The value of BC absorption coefficient was (44.8±31.8) Mm-1

and the ratio of absorption in extinction was 14.9%. Low wind speed

low rain frequency

and low temperature conditions were not conducive to the diffusion

transmission

and settlement of BC. Besides

it was found that the transmission in the north and northwest areas of Shanghai had a great influence on the mass concentration of BC

and the pollution trajectories of different air mass types accounted for the seasonal differences of BC concentration

indicating that the pollution of BC aerosols is the result of both local emission sources and external transmission.