TY JOUR TI Polarization dynamics of Pi2 pulsations at midlatitudes during development of substorms in the auroral zone KW magnetosphere KW geomagnetic disturbances KW auroral substorm KW geomagnetic pulsations Pi2 KW polarization of geomagnetic pulsations KW Russian Arctic sector KW magnetic observatories JO Solar-Terrestrial Physics AU Rakhmatulin, R.A. AU Pashinin, A.Y. PY 2018 IS 4 PB INFRA-M Academic Publishing LLC.