Preprints
https://doi.org/10.5194/angeo-2021-7
https://doi.org/10.5194/angeo-2021-7

  09 Feb 2021

09 Feb 2021

Review status: this preprint is currently under review for the journal ANGEO.

Revisiting the long-term decreasing trend of atmospheric electric potential gradient measured at Nagycenk, Hungary, Central Europe

Attila Buzás1,2, Veronika Barta1, Tamás Horváth3, and József Bór1 Attila Buzás et al.
  • 1Geodetic and Geophysical Institute, Research Centre for Astronomy and Earth Sciences, Sopron, Hungary
  • 2Doctoral School of Earth Sciences, Faculty of Science, Eötvös Loránd University, Budapest, Hungary
  • 3Institute of Forest- and Natural Resources Management, Faculty of Forestry, University of Sopron, Sopron, Hungary

Abstract. In 2003, a decreasing trend has been reported in the long-term (1962–2001) fair weather atmospheric electric potential gradient (PG) measured in the Széchenyi István Geophysical Observatory (NCK, 47°38' N, 16°43' E), Hungary, Central Europe. The origin of this reduction has been the subject of a long-standing debate, due to a group of trees near the measurement site which reached significant height since the measurements of PG have started. Those trees have contributed to the lowering of the ambient vertical electric field due to their electrostatic shielding effect. In the present study, we attempt to reconstruct the true long-term variation of the vertical atmospheric field at NCK. The time-dependent shielding effect of trees at the measurement site was calculated to remove the corresponding bias from the recorded time series. A numerical model based on electrostatic theory was set up to take into account the electrostatic shielding of the local environment. The validity of the model was verified by on-site measurement campaigns. The changing height of the trees between 1962 and 2017 was derived from national average age-height diagrams for each year. Modelling the time-dependent electrical shielding effect of the trees at NCK revealed that local effects played a pivotal role in the long-term decrease. The results suggest that earlier attempts could not quantify the shielding effect of the trees at NCK accurately. It was found that the reconstructed PG time series at NCK exhibits a significant increase between 1962 and 1997 followed by a decaying trend since 1997. It is pointed out that long-term variation in summertime and wintertime PG averages should be analyzed separately as these may contribute to trends in the annual mean values rather differently.

Attila Buzás et al.

Status: open (until 24 Mar 2021)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse

Attila Buzás et al.

Attila Buzás et al.

Viewed

Total article views: 211 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
186 22 3 211 0 0
  • HTML: 186
  • PDF: 22
  • XML: 3
  • Total: 211
  • BibTeX: 0
  • EndNote: 0
Views and downloads (calculated since 09 Feb 2021)
Cumulative views and downloads (calculated since 09 Feb 2021)

Viewed (geographical distribution)

Total article views: 153 (including HTML, PDF, and XML) Thereof 153 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Latest update: 07 Mar 2021
Download
Short summary
Based on on-site measurements and numerical modelling we eliminated the electrostatic shielding effect of nearby trees from the atmospheric electric potential gradient (PG) time series recorded at Nagycenk, Hungary, Central Europe revealing their actual variation between 1962 and 2009. The comparison with PG data from other stations around the globe implies that there have been coherent, possibly global changes in Earth's atmospheric electric field during the investigated time period.