A missing link in haze formation

Science Daily  November 25, 2019
Particles in the atmosphere that are 2.5 to 10 micrometers in size, can be inhaled, are potentially harming the heart and lungs. Alcohols in general and methanol in particular are believed to play a small role in atmospheric new particle formation (NPF) largely due to the weak binding abilities of alcohols with the major nucleation precursors. An international team of researchers (USA – University of Nebraska, University of Pennsylvania, Finland, China) has identified a catalytic reaction between methanol and sulfur trioxide (SO3) which can have unexpected quenching effects on the NPF process, particularly in dry and highly polluted regions with high concentrations of alcohols. Through simulation they have shown that the formation of methyl hydrogen sulfate (MHS) consumes an appreciable amount of atmospheric SO3, and MHS formation can cause a reduction of Sulfuric acid (SA) concentration up to 87%. The catalytic reactions between alcohols and SO3 need to be considered in atmospheric modeling in order to predict SA concentration from SO2, while also account for their potentially negative effect on NPF…read more. TECHNICAL ARTICLE