Spectral parameters of 1-4 mHz geomagnetic and auroral luminosity pulsations in the polar caps and near the polar boundary of the auroral oval
Tuesday, September 29, 2015
Nataliya Nosikova1,2, Nadejda Yagova1, Viacheslav Pilipenko3, Olga V. Kozyreva1, Lisa J Baddeley4 and Dag A Lorentzen4, (1)Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences, Moscow, Russia, (2)National Research Nuclear University MEPhI, Moscow, Russia, (3)Space Research Institute RAS, Moscow, Russia, (4)UNIS, Longyearbyen, Norway
Abstract:
Geomagnetic pulsations at the lowest ULF frequencies (1-4 mHz) are the dominating type of geomagnetic disturbances at very high geomagnetic latitudes corresponding to open field lines. However, the quantitative analysis of these disturbances is in the initial phase. In the present study the high-latitude 1-4 mHz pulsations are studied simultaneously in the geomagnetic field, auroral luminosity and particle flux in the geomagnetic tail. Instances of a rare type of geomagnetic substorm, which occur with no clear external trigger, are selected. These events can thus not be predicted from the standard analysis of solar wind parameters in front of the bowshock because these parameters are typical for undisturbed days. Geomagnetic and auroral luminosity pulsations observed during several hours preceding these “non-trigger” substorms are analyzed to examine a possibility for a substorm generation mechanism by intra-magnetospheric processes.
