A group of trees located at the eastern side of the atmospheric electric potential gradient (PG) measurement site in the Széchenyi István Geophysical Observatory at Nagycenk (NCK) was cut down on the 24^th February in 2020. In order to assess the impact of this event on the PG measurements, an electrostatic numerical model was built to model the effect of the removal of trees. Moreover, the PG data recorded between 2017 and 2021 were analyzed. It was found that the PG increased by up to 52% after the trees in question were cut down. Based on the numerical model calculations this enhancement was expected to be larger, 78%. Further investigations concerning the seasonal variation of the PG recorded in 2017–2021 affirm that this increase is not part of the regular seasonal variation of the PG and it is an anomaly most likely caused by the diminished electrostatic shielding effect due to the fewer remaining trees.

Attila Buzás and József Bór (2021): Investigating the impact of cutting down nearby trees on measured values of the atmospheric electric potential gradient data. Geophysical Observatory Reports, 2020, 6-13. https://doi.org/10.55855/gor2020.1