ELF Electromagnetic Waves and Ionospheric Physics SeminarNovember 26, 2025Anne Neska (IG PAS Warsaw) "On the impact of ground electric conductivity on ELF measurements - first insights" Abstract: Previous research has reported a systematic, site-dependent deviation in the azimuth direction estimation of strong lightning events determined from lightning detection networks to those determined from ELF measurements. Though heterogeneity in ground resistivity (such as highly conductive zones or an ocean coast) has been suspected as source of that deviation from the beginning, prove of it remained vague. We investigate the relation between that azimuth deviation and the electric properties of the subsurface in a quantitative way. In this contribution some basics of magnetotellurics, a sounding method for deriving electrical conductivity and its distribution in the solid Earth, will be presented. It can be expected that some concepts will be similar to those applying to the atmosphere - ionosphere boundary, and special attention will be drawn to the term of the geoelectric strike direction. It will be explained why data measured with both methods - magnetotellurics and ELF monitoring - in the same place are necessary for the intended investigation. First results from such a place which is Hylaty station in the SE Polish Bieszczady Mountains will be reported along with ongoing attempts to get similar data from other sites. Co-authors: Tibor Rubóczki, Tamas Bozóki, Janusz M³ynarczyk, Jerzy Kubisz Contact: Contact_ELFseminar(at)oa.uj.edu.pl |