Max Current – Current Derivative
A correlation between the pulse current peak and the current derivative is shown. Hover on the regression line to see the parameters. Furthermore the data from Garbagnati (taken from [1]) is plotted along. Other comparisons can be found in [2].
The towers of Garbagnati were 40 m high, located on mountain tops 980 and 993 m ASL and with 98% of upward flashes.
[1] Garbagnati and Lo Piparo, 1982 E. Garbagnati and G.B. Lo Piparo, Parameter von blitzströmen. Elektrotech. Z. etz-a, 103 (1982), pp. 61–65.
[2] Okabe, S.; Takami, J.; , “Evaluation of Improved Lightning Stroke Current Waveform Using Advanced Statistical Method,” Power Delivery, IEEE Transactions on , vol.24, no.4, pp.2197-2205, Oct. 2009
doi: 10.1109/TPWRD.2009.2016806
Charge-Current
Rakov [3] comment on the relation between Charge and Current following a paper from Berger [4] (including downward). The results are similar to those obtained at the Säntis. Its important to annotate that the effective height at Sant Salvatore’s 70m tower and 640m mountain was 350m (according to Ericksson and cited in page 50 of [5]. (50 percent of the flashes recorded were classified as “unidentified”) with a percentage of 84% of upward flashes. The Säntis mountain is 2505m ASL and the tower height is 124m. The upward/downward flashes percentage is not yet known for the first part of the study.
[3] Rakov. V. A. Lightning Discharge and Fundamentals of Lightning Protection. X International Symposium on Lightning Protection 9th-13th November, SIPDA. 2009 – Curitiba, Brazil
[4] Berger, K. Mesungen und Resultate der Blitzforschung auf dem Monte San Salvatore bei Lugano, der Jahre 1963-1971. Bull. SEV 63: 1403-22, 1972.
[5] Rakov V.A., Uman. M.A. Lightning: Physics and Effects. Cambridge University Press, 687 p., 2003, ISBN 0521583276, PB ISBN 0521035414.
Pulse Multiplicity
It is interesting to see how the Pulse Multiplicity, that is, the number of pulses per flash classified as such, its related to other parameters. The figure presents its plot against the Charge, the Maximum Current and the Current Derivative. The more important correlation can be seen with the Charge, perhaps because as the cloud has a finite amount of total charge and the discharge phenomena transfer it to the ground, the flashes with larger multiplicities transfer less charge per pulse.
