Transient Response of the Top Structure of the Peissenberg Tower to Lightning.

Subject matter of this paper is the analysis of the high-frequency oscillation of the lightning currents which have been measured at the top of the Peissenberg Tower, Germany. The oscillations appeared only during the initial period of fast-rising currents. In 2007, the tower top section was removed and replaced by a smaller construction. As a result, the frequency of the oscillation changed from formerly ∼12.5 to ∼6 MHz. The oscillations could be reproduced with simulations using the computer code CONCEPT II. It was found that the high-frequency current oscillation is caused by the transient response of the top structure of the Peissenberg Tower. The currents at lower sections of the tower as well as the nearby electric and magnetic field (∼190 m from the tower) contained less significant pulsation. As a major result, the presence of the tower increased the risetime of the fast-rising currents. Probably for this reason, the highest maximum current steepness ever recorded was limited to 155 kA/μs. [ABSTRACT FROM AUTHOR]