The vertical gradient of Electro-Atmospheric potential at Macerata (Italy) (Central East Apennines)

Abstract

This work studies eleven years of measures of the gradient<br />of electro-atmospheric potential carried out in the Observatory of<br />Macerata (East Central Apennines). The medium yearly and monthly<br />values as well as the medium hourly values have been calculated. The<br />calculations are based on the values of five calm days chosen with probabilistic<br />methods from all the calm days of the month considered. The equation lias also been found from the medium hourly curve by<br />means of harmonic analysis. Then the harmonics have been examined<br />stopping at the third, and it has been found that these reflected the different<br />general and local components such as that due to the masses of air of maritime<br />origin and that due to the masses of continental air operating alternatively<br />in the region of observation. The general minimum of the local hours<br />"&gt; a. m. (4 TU) is clearly shown by the first harmonic, and it is also present<br />in the medium hourly curve but appears in this less accentuated than what<br />we would expect it to be.<br />Finally the behaviours of the vertical gradient in clear, cloudy and<br />calm days have been studied and the different results compared.<br />The behaviour of the parameter of the atmospheric electricity in relation<br />to the solar phenomena has also been studied and in particular with the<br />behaviour of the sunspots during the eleven years of observations.