Lifetime of a polarization jet during long-term magnetic storms

Abstract

The paper examines conditions of occurrence and typical time scales of a polarization jet by measuring ionospheric parameters from DMSP satellites (h~830 km) and using data from the ground-based ionospheric station Yakutsk (YA462) during strong and long-term geomagnetic storms. The polarization jet at the ionospheric station Yakutsk was recorded in the dusk sector at the background of substorm disturbances when the geomagnetic index SME reached values from 1000 to ~3000 nT, and, according to data from the magnetic observatory Yakutsk (YAK), there was a positive bay ~50–100 nT in the geomagnetic field H component and ~100–200 nT in its Z component. We show that the lifetime of the polarization jet or narrow troughs in ionospheric plasma in the subauroral ionosphere during strong and long-term magnetic storms can be as long as 12 hrs.

Keywords

• ionosphere
• magnetosphere
• polarization jet
• sme index
• plasma drift
• narrow dip
• magnetic storm and substorm