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The analysis of the Pi 2 pulsations for the period May 15, 1970, to May 14, 1971, from Ottawa, Meanook, Baker Lake, and Resolute Bay observatories reveals the following: (1) Pi 2 pulsations occur most frequently near midnight at Ottawa, Meanook, and Baker Lake and near 15¿1 h LT at Resolute Bay; the 18¿1 h LT peak at Baker Lake was found to be quite strong, especially during winter. Also at Baker Lake and Resolute Bay, Pi 2's occurred at later hours during magnetically quiet conditions but at earlier hours during magnetically disturbed conditions. (2) The amplitude of Pi 2 is found to be largest before midnight at Ottawa and Meanook and at midnight at Baker Lake. (3) The period of Pi 2 is noted to be minimum in the morning and maximum in the evening at Ottawa and Meanook. Also, Ottawa results indicate that Pi 2 periods undergo a nonseasonal annual variation. (4) Both the occurrence and amplitude of Pi 2 are found to increase with increasing magnetic activity to a certain level of Kp, which varied among the stations. (5) Some evidence of a 27-day recurrence tendency in the period of Pi 2 is found. A lunar influence on the occurrence of Pi 2 is also noted, and this effect deserves further attention. |