Some Return Stroke Characteristics of Negative Lightning Flashes Recorded at the Peissenberg Tower

Subject matter of the paper is the analysis of the return stroke characteristics of negative lightning flashes recorded with the Peissenberg Measuring Station, Germany. Four negative first return strokes were measured. All of them were single-stroke lightning having a first stroke, but no subsequent stroke. The arithmetic mean value is 42.8 kA for the peak current, 7.4 mu s for the 10% to 90% current risetime, 13.5 C for the charge, 182 .10(3) A(2)s for the specific energy (action integral), and 15.5 kA/mu s for the maximum current steepness. The associated electric fields exhibited a field change of opposite polarity prior to the initiation of the return stroke current. The same waveform was found for the electric field of other triggered negative upward lightning, except of the different time scale. The currents of the total of 105 negative subsequent return strokes were also recorded, 68 of them with the measurement equipment were used up to the year 1999, and 37 of them with the new measurement equipment were used since 2008. Based on the measurements up to 1999, the arithmetic mean values of the current peak and of the maximum current derivative are 9 kA and 45 kA/mu s, respectively. For the measurements since 2008, the arithmetic mean value of the current peak is 10.1 kA.