On the presence in the Earth magnetosphere of oscillations with the period of 160 min caused by pulsations of the Sun

Optical observations of solar pulsations with the period 160sup(m) together with the measurements of the amplitudes envelope of the micropulsating geomagnetic field Pc 3, 4 were processed by cosinor analysis. It has been found that the amplitudes of Pc 3, 4 are modulated by the period 160sup(m) with the stable phase. This modulation of Pc 3, 4 might be possibly caused radiation over the range lambda100-900 A. The maximum of radiation flux delays with reference to the maximum of expansion velocity of the Sun to > or approximately 1/3 of the period. Pc amplitudes essential depends on a season. These micropulsations on the middle latitudes are constantly observed in summer, with a little smaller amplitude - in spring and autumn and considrably less - in winter