Abstract:In this study, we consider the geoelectric storm events that occurred from 2015 to 2018 in China and identify the bases for quickly and accurately judging such phenomena by summarizing and analyzing the variation characteristics of screened data:(1) When a geoelectric storm occurs, the observation data of a geoelectric field are suppressed and the variation amplitude becomes more than twice the normal diurnal variation value. (2) Geoelectric storm events have a wide-area synchronicity, which can be judged by comparing the observation data of several stations. (3) A geomagnetic storm and geoelectric storm have homology, and the former can be judged by geomagnetic observations. (4) After the initial judgment, the influence of the observation system, natural environment, human interference, and environmental events should also be excluded before a geoelectric storm event is affirmed. The analysis results of the waveform characteristics of a geoelectric storm show that its amplitude is generally proportional to the K index, but the amplitude of a geoelectric storm at the same station greatly varies under the same K index. Under the same geoelectric storm, different stations have different amplitude responses, and the latitude effect is unclear, so it has regional characteristics. These characteristics may be related to the geological conditions of a station, the electrode distribution of a geoelectric field, and other factors.