Traffic pollution alters the atmospherics’ electric field, study finds

A new study shows that traffic-related pollution in a major urban area in central Israel produces immediate, measurable changes in the atmospheric electric field, while particulate matter creates slower, delayed effects. The research also identifies a strong weekend signal, with reduced emissions leading to a marked weakening of the electric field. These findings are important because they point to atmospheric electricity as a highly sensitive, real-time indicator of urban air quality, capable of detecting rapid changes in emissions that conventional monitoring may miss. The results suggest a new way to track the immediate impact of traffic patterns and emission-reduction policies on city air, with potential implications for urban planning, environmental monitoring, and public health.

A new collaborative study has uncovered how everyday pollution from traffic and industry measurably alters the atmospheric electric field over the Tel Aviv metropolitan area in Israel. The research was led by Dr. Roy Yaniv from Hebrew University and the Gertner Institute at Sheba medical center, Dr. Assaf Hochman from the Institute of Earth Sciences at Hebrew University and Prof. Yoav Yair from Reichman University together with Itay Froomer from Hadera High School and the Israeli Museum of Medicine and Science (Technoda), who conducted the work as part of the Ministry of Education’s 5-unit physics research track. This unique partnership highlights an exceptional model of collaboration between academia, the education system, and the wider community.

Using data from an electric field mill, which was sponsored by the Ministry of Education and Holon municipality, and is in built in the Center for Technological Education (Roter house) in Holon, alongside high-resolution air-quality and meteorological records, the researchers examined how fine particulate matter (PM2.5) and nitrogen oxides (NOx) influence the Potential Gradient (PG), a key measure of the atmospheric electric field under fair-weather conditions. “What we observe is a direct physical link between emission peaks and electrical variability,” the researchers explained. “NOx reduces atmospheric conductivity very quickly, so the electric field responds almost instantaneously during traffic rush hours.” Their findings show a clear and immediate electrical response to NOx pollution, while PM2.5 affects the electric field more slowly due to its longer atmospheric lifetime and different microphysical behavior.

The study also reveals a pronounced “weekend effect”: on Fridays and Saturdays, when traffic and industrial activity drop sharply in Israel, NOx and PM2.5 levels decrease and the atmospheric electric field weakens accordingly. “The weekend signal demonstrates just how sensitive the electric field is to changes in human activity,” the researchers noted. “When emissions decline, the electrical environment adjusts at once, providing a high-resolution indicator of urban atmospheric conditions.” This link between human activity and electrical properties of the lower atmosphere strengthens the case for using atmospheric electricity as an additional tool for environmental monitoring, especially in densely populated regions.

By demonstrating how urban emissions reshape the near-surface electric field, the research opens the door to new interdisciplinary approaches to air-quality assessment and public-health preparedness. It also underscores the value of educational–scientific collaborations that engage high-school students in real-world atmospheric and environmental research. “Integrating air-quality data with electric-field measurements gives us a clearer picture of how the lower atmosphere evolves moment by moment,” the researchers added. “It’s a framework that can support both scientific insight and practical environmental decision-making.”