The highest mean and median peak currents were detected in the year 1992. This is a clear indication of the influence of detection efficiency (DE) on the lightning peak current statistics determined with lightning location networks because during 1992, the first year of network operation, numerous sensors outages degraded the DE of the network significantly. A network of low DE does not detect small peak current flashes and therefore the median of the distribution is biased towards higher values. Since an improvement of the sensor power supply and the over voltage protection of the sensor communication in winter 1992/1993 the DE is much more stable inside Austria.

The lightning current distribution 1996 (negative / positive) was determined with a system using only IMPACT sensors and shows that positive flashes have higher median values than negative flashes. Flashes with peak currents greater than 100 kA are rarely detected, whereas positive flashes with peak currents exceeding 200kA are not uncommon.

A comparison of the lightning peak current distributions of negative flashes with the lightning peak current distributions of positive flashes for the years 1998-2001 shows that contrary to the previous years the median values for the period 1998 till 2002 are almost identical. The main reason for this is the integration of ALDIS within a multinational lightning detection network including sensors located in neighbouring countries. In the German and the Slovenian network sensors are used which sometimes do not distinguish correctly between Cloud to Cloud (CC) and Cloud to Ground (CG) flashes. Thus a small fraction of CC flashes is erroneously classified as positive CG flashes. Because CC flashes normally have smaller amplitudes than CG flashes the amplitude distribution of positive flashes is biased towards smaller values