A RESULT ON PC 3-4 WAVES IN THE INDIAN EQUATORIAL REGION

A few characteristics of Pc 3-4 geomagnetic pulsation recorded at a st ation close to the equatorial electrojet in the Indian region under va ried ionospheric conditions are reported. The polarization characteris tics of these pulsations during counter electrojet condition are found to change in their ellipticities and orientation axes. These are attr ibuted to either height distortions of ionospheric electric fields dur ing the counter electrojet time or to changes of gyrotropic MHD waves that might be endogenously generated by the turbulence of equatorial e lectrojet.