Snowpack Chlorine Chemistry in Wintertime Urban Boundary Layer

Regents Of The University Of Michigan - Ann Arbor, Ann Arbor MI

Investigators

Abstract

This project focuses on investigating the effects of road (de-icing) salt application on urban air quality. The transfer of chlorine from road salts (NaCl) to the gas phase can alter the fate of atmospheric pollutants. Both field work and modeling will be conducted to investigate the production of nitryl chloride (ClNO2) from an urban snowpack. The three main hypotheses are: (1) ClNO2 is produced from road salt-laden snow by heterogeneous reaction of N2O5 with snow chloride; (2) N2O5 deposition to the urban snowpack, coincident with ClNO2 production, can be observed and quantified through near-surface vertical profile measurements; and (3) Snowpack ClNO2 production impacts urban winter daytime atmospheric oxidant conditions. This project supports the training of both graduate and undergraduate students. Outreach activities will be conducted through the UM Museum of Natural History Science Communication Fellows Program, part of the NSF Portal to the Public Network.