Canadian Wildfire Smoke Impacts on Reduced Nitrogen in the Upper Midwest: Insights From the 2023 Fire Season
Journal Article
Overview
abstract
Abstract; ; Wildfires are the largest terrestrial source of atmospheric ammonia (NH; 3; ), yet their impacts on NH; 3; concentrations and ammonium (NH; 4; +; ) deposition remain poorly quantified. In this study, we evaluate the effects of the record‐breaking 2023 Canadian wildfire season on NH; 3; concentration and NH; 4; +; deposition across the Upper Midwest. This study integrates satellite observations, ground‐based data, and in situ aircraft measurements. In May–June 2023, NH; 3; concentrations increased at 83% of ground sites, and NH; 4; +; deposition flux rose at 100% of ground sites in the Upper Midwest. Satellite data showed significantly higher column‐averaged NH; 3; in 47% of grid cells in the Upper Midwest. On 1 August, a smoke plume over the Midwest corresponded with an AEROMMA flight observing enhanced NH; 3; , NH; 4; +; , carbon monoxide, and acetonitrile. These findings highlight the substantial impact of wildfire smoke on NH; 3; and NH; 4; +; at regional scales, with implications for nitrogen cycling, air quality, and atmospheric modeling.;
