抄録
From dispersions of whistling atmospherics ionization-densities in the outer atmosphere are roughly estimated. And diurnal variations of electron density are obtained in lower parts of outer atmosphere. In order to examine the origin of the ionization kp index is compared with rate occurrence of whistlers, but no correlation is obtained, though the correlation is altered slightly positive when value of kp is taken two days in advance. And observations at low latitudes show that an ionized hydrogen atomosphere is likely in the exosphere.
