Fig. 5

Summary of ionosonde observations on July 4, 2019, a location of 4 ionosonde stations of NICT (Okinawa, Yamagawa, Kokubunji and Wakkakai), b ionogram from Kokubunji at 0930 JST, c variation of foEs values from 4 stations, d ionogram from Kokubunji at 0600 JST, e ionogram from Wakkanai at 2230 JST