AAAR 33rd Annual Conference
October 20 - October 24, 2014
Rosen Shingle Creek
Orlando, Florida, USA
Abstract View
Investigation of the Sources and Evolution Processes of Severe Haze Pollution in Beijing in January 2013
YELE SUN, Qi Jiang, Zifa Wang, Pingqing Fu, Jie Li, Ting Yang, Yan Yin, Institute of Atmospheric Physics, CAS
Abstract Number: 33 Working Group: Urban Aerosols
Abstract China experienced severe haze pollution in January 2013. Here we have a detailed characterization of the sources and evolution mechanisms of this haze pollution with a focus on four haze episodes that occurred during 10-14 January in Beijing. The average PM$_1 mass concentration during the four haze episodes ranged from 144 – 300 µg m$^(-3), which was more than 10 times higher than that observed during clean periods (14 µg m$^(-3)). All submicron aerosol species showed substantial increases during haze episodes with sulfate being the largest. Secondary inorganic species played enhanced roles in the haze formation as suggested by their elevated contributions during haze episodes. Positive matrix factorization analysis resolved six organic aerosol (OA) factors including three primary OA (POA) factors from traffic, cooking and coal combustion emissions, and three secondary OA (SOA) factors. The OA compositions varied greatly among different haze episodes. Overall, SOA contributed 41 – 59% of OA with the rest being POA. Coal combustion OA (CCOA) was the largest primary source, on average accounting for 20- 32% of OA, and showed the most significant enhancement during haze episodes. A regional SOA (RSOA) was resolved for the first time which showed a pronounced peak only during the record-breaking haze episode (Ep3) on 12-13 January. The regional contributions estimated based on the steep evolution of air pollutants were found to play dominant roles for the formation of Ep3. The regional contribution on average accounted for 66% of PM$_1 during the peak of Ep3 with sulfate, CCOA and RSOA being the largest fractions (>~75%). Our results together suggest that stagnant meteorological conditions, coal combustion, secondary production, and regional transport are four main factors driving the formation and evolution of haze pollution in Beijing during wintertime.