An Investigation of Near-Equatorial Geomagnetic Pi2 Pulsations

There is understanding to date that Pi2 pulsations have two sources. One source is a high-latitude one and is due to fluctuations of electro jet parameters. The other source is a mid-latitude one and is driven by a global mode excited in the Earths plasmasphere. There is experimental evidence that in the nearequatorial regions the character of Pi2 excitation is different from high and mid-latitudes. In this connection,we investigated the amplitude-spectral-polarization characteristics of Pi2 pulsations using the date from nearequatorial Chinese stations. The detected regularities in the excitation of near-equatorial Pi2 pulsations are used in the discussion of the possible physical mechanism that is responsible for the generation of these pulsations.