TY - JOUR T1 - Contribution of hydroxymethane sulfonate to ambient particulate matter: A potential explanation for high particulate sulfur during severe winter haze in Beijing JF - Geophysical Research Letters Y1 - 2018 A1 - Jonathan M. Moch A1 - Eleni Dovrou A1 - Loretta J. Mickley A1 - Frank N. Keutsch A1 - Yuan Cheng A1 - Daniel J. Jacob A1 - Jingkun Jiang A1 - Meng Li A1 - J. William Munger A1 - Xiaohui Qiao A1 - Zhang, Qiang AB -

PM 2.5 during severe winter haze in Beijing, China, has reached levels as high as 880μg/m3, with sulfur compounds contributing significantly to PM 2.5 composition. This sulfur has been traditionally assumed to be sulfate, although atmospheric chemistry models are unable to account for such large sulfate enhancements under dim winter conditions. Using a 1-D model, we show that well-characterized but previously overlooked chemistry of aqueous-phase HCHO and S(IV) in cloud droplets to form a S(IV)-HCHO adduct, hydroxymethane sulfonate, may explain high particulate sulfur in wintertime Beijing. We also demonstrate in the laboratory that methods of ion chromatography typically used to measure ambient particulates easily misinterpret hydroxymethane sulfonate as sulfate. Our findings suggest that HCHO and not SO2 has been the limiting factor in many haze events in Beijing and that to reduce severe winter pollution in this region, policymakers may need to address HCHO sources such as transportation.

 

VL - 45 UR - https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2018GL079309 ER -