资源环境科技发展态势分析平台

The results of observations of radio emission from thunderclouds in a wide frequency range with a high temporal resolution carried out in the Upper Volga region near Nizhny Novgorod are compared with the data from worldwide and regional lightning location networks. Two parameters are chosen to characterize the radio emission: root mean square (corresponding to the emission intensity) and kurtosis (to testify to the presence of a pulsed component in the emission) of its distributions at short time intervals. It is shown that the intensity of radio emission as a whole reflects the level of thunderstorm activity at distances up to 50 km from the point of observation. A similar correlation also takes place for the kurtosis of the emission. Comparison with events detected by lightning location networks shows that they are often preceded by a well-defined behavior of the above parameters. The emission begins suddenly with a moderate level of intensity and a high value of kurtosis that lasts from few to more than one hundred of milliseconds. Then the kurtosis decreases permanently with approximately the same intensity of the emission that can correspond to a step leader stage of a lightning discharge. The radio frequency event is ended by a sharp increase in the emission intensity simultaneously with a decrease of the kurtosis to the background level, and exactly the same moment corresponds to a lightning location network event that can be associated with the return stroke of a lightning discharge. It should be mentioned that a number of events from lightning location networks have no such manifestations in the recorded radio emission and vice versa.