Measurement report: Intensive biomass burning emissions and rapid nitrate formation drive severe haze formation in the Sichuan Basin, China – insights from aerosol mass spectrometry

[摘要] Haze pollution is a severe environmental problem, caused by elevation offine particles (aerodynamic diameter 200   µg m −3 , suggesting the insignificant effect ofaqueous-phase reactions on OOA formation. Among the three haze episodesidentified during the whole campaign, the driving factors were different:the first haze episode (H1) was driven by nitrate formation throughphotochemical and aqueous-phase reactions, and the second haze episode (H2)was mainly driven by the intense emission of primary organic aerosols frombiomass burning and vehicle exhaust, while the third haze episode (H3) wasmainly driven by reactions involving nitrate formation and biomass burningemission. HOA and BBOA were scavenged, while OOA, nitrate and sulfateformation was enhanced by aqueous-phase reactions during fog periods, whichresulted in the increase of O:C from pre-fog to post-fog periods. This studyrevealed the factors driving severe haze formation in the SCB and implied thebenefit of controlling nitrate as well as intense biomass burning andvehicle exhaust emission for the mitigation of heavy aerosol pollution inthis region.

[学科分类] 医学（综合）