Patterns of Spatial Distribution of Positive Thunderstorm Discharges in Eastern Siberia

摘要

Patterns of spatial distributions of the thunderstorm positive discharges, which were obtained by using a one-point storm direction and distance finder with observation radius of~1200 km in Eastern Siberia in 2003-2007, are considered in this paper. It was found that distributions of positive discharges reflect, in general, overall patterns of thunderstorm activity. Two centers corresponding to maximum activity of the negative storm discharges are located in southwest; however, they were dominating (in terms of their intensity) only in 2005. Two other centers are more intense: the northeastern one was especially strong in 2003, 2004, 2006 and the eastern one was dominating in 2003 and 2007. The northeastern centers are the most active in the beginning and the end of the season. In these areas, ratio of positive and negative discharge fluxes can exceed 1. Activity of the eastern center, whose large part is situated in mountains, can be explained by neighborhood of the Sea of Okhotsk. The mentioned patterns of spatial distributions of positive storm discharges indicate that the geographic conditions play a significant role in their origination in the eastern part of Siberia. In the southern and western regions, a typical electric structure of thunderstorm clouds develops with main negative charge in the lower part of a cloud. At the same time, in the high latitudes, in the mountains, evidently, a different mechanism is realized, leading to the inverted location of charges in a cloud.