Diurnal Variation in Atmospheric Electricity

Abstract

In order to eliminate short-period fluctuations due to local effects, daily courses of potential gradient, conductivity and air-earth current were smoothed out by taking hourly overlapping means of 5 hours and the interrelationship between each element was examined on every day. In urban district, the production of man-made nuclei begins following human activity in the early morning before sunrise and they accumulate in the lowest stable layer of the exchange layer. In the daytime, when the wind rises, the nuclei are transported into the upper layers in the exchange layer by vertical turbulent mixing due to forced convection, and there diffused out horizontally. The eliminated short-period fluctuations are on the average 27% of the concerned elements. Examining diurnal variations of the fluctuations, there is neither evidence that they are caused by local generators other than the thunderstorm generator nor evidence that they are directly connected to strength of turbulence of the air.