Abstract
During the abrupt changes of the near-surface (NS) field according to
the end of storm oscillations (EOSO) scenario, we observe prolonged
thunderstorm ground enhancements (TGE). The EOSO starts with the
reduction of the lower positively charged region (LPCR) with the
following falling of the near-surface (NS) electric field in the deep
negative domain for ≈12 minutes. During these minutes we observe
prolonged TGE and graupel fall. Afterward, the NS field returns again to
a positive value, although smaller than the initial one. Finally, the
field returns to fair-weather conditions. Thus, the ending phase of the
storm is followed by the degradation of all 3 charged layers of a
tripole.