Atmospheric electric field variations and its correlation with air quality index as observed from two low-latitude Indian stations

Atmospheric electric field (AEF) variations and their relationship with air quality indicators like the Air Quality Index (AQI) are vital in understanding both local AEF and global electric circuit (GEC) behaviors. The present study investigates the diurnal and seasonal variations of AEF at two different locations in West Bengal, India: Bagula (BGL) and Purulia (PRL). The fair weather AEF variations from these sites are compared with the global standard Carnegie curve and with other global sites. Compared to the urban site, which exhibits notable departures from the Carnegie curve, the fair-weather mean diurnal variation at the rural site displays distinct GEC signals. The AEF variations are also analyzed with respect to the AQI, and particulate matter in those two sites to evaluate the impact of local air pollution on atmospheric electricity. Moderate to strong correlations between AEF and AQI across different seasons are obtained. The seasonal AEF variation and AQI have a strong link for the winter season (r = 0.75), the post-monsoon season (r = 0.59) at BGL, and the post-monsoon season (r = 0.63) at PRL. The monsoon season experienced the lowest correlation in both sites. The AEF exhibits a strongly negative association with the AQI on a daily scale during periods of extreme pollution in both sites, suggesting the formation of a negative space charge layer that modifies AEF. Results indicate the possibility of estimating AQI values from the AEF measurements during high episodes of pollution.