Influence of Wildfire Smoke on the Regional Air Quality in the U.S. Midwest

Parth Thakre, Kerstin Cox, Samantha Galicki, GOURI PRABHAKAR, Purdue University

     Abstract Number: 425
     Working Group: Remote and Regional Atmospheric Aerosol

Abstract
The Midwestern United States is largely an agricultural region without active wildfires. Yet, in the recent years many days in the summer months have experienced smoky skies due the long range transport of smoke from wildfires in Western U.S. and Canada. The current study aims to investigate whether this smoke has influenced ground level air quality in this region, and if so, how it has changed over the last two decades. The study analyzes long-term concentrations of atmospheric aerosol species indicative of wildfire emissions measured at 14 ground sites across eight Midwestern states through the IMPROVE (Interagency Monitoring of Protected Visual Environments) network. Preliminary findings indicate significant seasonal changes in wildfire-associated aerosol components, namely Organic Carbon (OC), Elemental Carbon (EC), and Potassium. The ratio OC:EC appears to be a better indicator of wildfire smoke instead of absolute concentrations of the individual species. The analysis also suggests a statistically significant increase in wildfire smoke influence on aerosol composition during the summer in the last decade compared to the past. Understanding these changes over recent years is crucial to assessing future air quality trends and risks to human health from exposure to wildfire smoke in this region.