Presentation: 2025 ND EPSCoR Annual conference 

October 21, 2025, NDSU Memorial Union, Fargo, North Dakota

Observations of Surface Electric Field Anomalies from Wildfire Smoke over Grand Forks

The Earth’s atmosphere is an electric circuit. This circuit consists of a downward-pointing electric field (E-field) inducing a current between the ionosphere and Earth’s surface in fair-weather conditions and an upward-pointing current from global thunderstorm activity. Phenomena such as clouds, dust, and smoke can alter the ambient E-field and thus the global electric circuit. Earth’s ambient E-field can be measured locally using surface-based electric field mills (EFMs). While the global electric circuit has been studied since the 18th century, the effects of wildfire smoke on the local ambient E-field are not widely studied. From May 11 to May 13, 2025, Grand Forks experienced periods of smoky conditions from wildfires in Manitoba. Observations of Earth’s quasi-static atmospheric E-field were taken by three EFMs, two at the University of North Dakota (UND) and one 25 miles west-southwest of UND. Smoke overhead enhanced the E-field at the surface to values well above the background state. We will examine the observed surface electric field anomalies, surface meteorological conditions, and atmospheric aerosol loading corresponding to smoky conditions. Insights into the effects of wildfire smoke on the global electric circuit will be discussed.