Parameters of thunderstorm activity and lightning discharges in Central Yakutia from 2009 to 2012

The results of integrated instrumental observations of thunderstorm activity around Yakutsk at a radius of 400 and 30 km are presented. The seasonal course of thunderstorm activity was found to contain characteristic peaks in the first 10 days of June and the last 10 days of July or early August. The fraction of cloud-to-ground discharges in Central Yakutia is 40–60%, which is consistent with observations in Western Siberia (40–50%). The number of positive discharges to the ground was 8–15% of all cases of discharges to the ground, which is consistent with observations in Germany (17%) and slightly exceeds the observed number in the Caucasus (2.2–8.2%) and United States (4.5%). The thunderstorm activity in Yakutsk is three times higher than in the area around Yakutsk with a radius of 400 km, which can be explained by the fact that the city is a heat island.