Differences in carbonaceous aerosol of fine particles between haze and non-haze days, Beijing

Abstract

In order to illustrate the factors dominating haze events over Beijing occurred in January, 2013, ambient fine particulate matter (PM2.5, particles with aerodynamic diameter less than or equal to 2.5 μm) samples were collected from January 16 to 31, 2013 at an urban area of Beijing. Daily meteorological parameters including atmospheric pressure, temperature, wind speed, and relative humidity (RH) were recorded. Carbonaceous aerosols in PM2.5 including elemental carbon, organic carbon, PAHs, n-alkanes and levoglucosan were determined to compare the concentration differences between haze days and non-haze days. Associations between PM2.5 carbonaceous aerosols and meteorological parameters were examined. Significant increases of carbonaceous aerosols are found in haze days than those in non-haze days, indicating primary emission sources play a role in haze events occurred in January, 2013. Meteorological parameters do not correlate with carbonaceous aerosols, supporting the regional transport is not dominant factor controlling haze formations. Our results show the primary emissions and meteorological conditions co-contribute the haze formation in Beijing during the sampling period of January, 2013.