Fig. 8From: Characteristics of the atmospheric electric field and correlation with CO2 at a rural site in southern BalkansMean diurnal variation of potential gradient (PG) and atmospheric CO2 for the period June 2011 to May 2012. The PG values were obtained from the all weather (AW) conditions dataset excluding the days of precipitation events or |PG| > 1 kV m−1. Error bars denote the standard errorBack to article page