抄録
Geomagnetic pulsations with periods between 180 and 300sec recorded at 7 Canadian magnetic observatories during 1967 were examined to determine the relationships of occurrence, amplitude and period to latitude, time and the level of magnetic activity. Their characteristics are compared with those of long-period Pc5's (periods 300 to 600sec). Results are examined in the light of existing theoretical models. However, it has been found that these models do not explain satisfactorily the observed evening occurrence peak in the polar cap.
