ИСТИНА

Ground-based Pc1 geomagnetic pulsation polarization as a proxy of the plasmapause location Feygin F. Z., Khabazin Yu. G., Kleimenova N. G., Malysheva L. M. Schmidt Institute of Physics of the Earth, RAS, Russia The typical magnetospheric ion-cyclotron waves are observed on the Earth’s surface as Pc1 geomagnetic pulsations in the 0.2–5 Hz range. The Pc1 pulsations are generated by cyclotron instability of the protons of the Earth radiation belt in the equatorial plane of the magnetosphere in the form of Alfven left-hand polarized waves. Here we present the scenario of the Pc1 pulsation propagation from the region of their generation in the magnetosphere (most likely in vicinity of the plasmapause) to a ground-based receiver, including the ionospheric waveguide (in the F2 layer). The waves propagate in this waveguide horizontally over long distances in latitude and longitude with very little attenuation, but herewith the left-hand polarized waves very rapidly attenuate with a distance, and the left-hand polarized waves transform into the right-hand polarized, fast magnetosonic waves. Thus, on the ground, near the plasmapause projection, the polarization of the Pc1 geomagnetic pulsations should be left-handed. We curried out the analysis of the latitudinal distribution of the about 200 events of Pc1 wave polarization at the Scandinavian chain of induction magnetometers and confirmed that wave polarization can use as a natural proxy of the location of the plasmapause projection. Feygin F.Z., Khabazin Yu.G., Kleimenova N.G., Malysheva L.M. Ground-based Pc1 geomagnetic pulsation polarization as a proxy of the plasmapause location // Fourteenth workshop Solar Influences on the Magnetosphere, Ionosphere and Atmosphere Primorsko, Bulgaria, June 06÷10, 2022 Book of abstracts, p. 13. DOI: 10.31401/WSoz.2022.abs