Conjugate properties of Pi3/Ps6 pulsations according to Antarctica-Greenland observations

Abstract

We consider interhemispheric properties of fine structure of substorm – quasi-periodic geomagnetic fluctuations, Pi3 pulsations, using data from conjugate magnetometers in Antarctica and Greenland. Pi3 pulsations are found to accompany both the substorm expansion/recovery phases and the steady magnetospheric convection (SMC) events. The epicenter of Pi3 power is at the same latitude as maximal amplitude of magnetic bays. The interhemispheric properties of Pi3 pulsations are not consistent: in some events, coherent in-phase magnetic oscillations are observed in both hemispheres, in others, periodic variations are observed in one hemisphere only. When Pi3 pulsations are observed in both conjugate sites, their H-components are in-phase, which corresponds to the fundamental mode of field line oscillations between high-conductive ionospheres. Conjugate observations have provided an additional information on an elusive mechanism of Pi3 pulsations.