Measuring global signals in the atmospheric electric field at high latitude sites

Abstract:

Previous research has shown that the study of the global atmospheric electrical circuit can be relevant to climate change studies, and this can be done through measurements of the atmospheric electric field near the surface in fair weather conditions. However, electric field measurements can be highly variable due to different local effects (e.g., pollution, convective processes in the planetary boundary layer). In order to try to minimize these effects, electric field measurements can be performed at remote locations where anthropogenic influences are small (e.g., mountains, islands, polar regions). In this work we present atmospheric electric field measurements from five stations installed at high latitudes in the Southern and Northern Hemisphere. This is the first description of new datasets from Halley, Antarctica; and Sodankyla, Finland. The effect of the polar cap ionospheric potential is significant at some of these polar stations and a detailed study has been performed to analyze its effect on the electric field measurements reported here. After removing the polar cap potential influence, we calculate annual, seasonal and monthly electric field daily curves of electric field. The results show a great agreement when compared with the ‘universal’ Carnegie curve. Additionally, a Lomb-Scargle periodogram and Wavelet analysis were performed, where possible, to find significant periodicities.