Fair weather electric field variability in Buenos Aires: The role of traffic and pandemic lockdowns

Abstract

The potential gradient variable (PG) is sensitive to several atmospheric processes. This study analyses the effect of traffic on the PG recorded at the Buenos Aires station under fair weather (FW) conditions. To identify the existence or not of an effect of traffic on the PG (FW), different statistical techniques were used. Significant differences were found in the daily means of PG (FW) between weekdays (W) and weekends (Wd), with consistent patterns throughout the year. In addition, spectral analysis revealed a significant seven-day cycle. When vehicular flow and nitrogen dioxide (${\mathrm{NO}}_2$) concentrations were examined for both W and Wd days, they showed a variation consistent with the changes observed in PG (FW). Although aerosol optical depth (AOD) showed some changes in its daily variability, it did not show significant differences in its daily means. During the SARS-CoV-2 confinement in 2020, a decrease in PG (FW) was observed, accompanied by a decrease in vehicular flow and ${\mathrm{NO}}_2$, reinforcing the idea of the influence of these emissions on PG (FW). These results highlight the importance of considering anthropogenic effects when analysing PG (FW) in urban areas, especially in locations with low measured pollutant emissions.