Multi-Instrument Approach to Study Polarization Jet/SAID and STEVE

Abstract

In this study, we employ a unique multi-instrumental approach for a comprehensive examination of Polarization Jet (PJ) (or, another name, Subauroral Ion Drift (SAID)). A diverse set of data is used to assess the connection between the appearance of the inhomogeneous structure of PJ/SAID and its reflection in ground-based observations during geomagnetic activity. Our approach combines satellite (Defense Meteorological Satellite Program, NorSat-1, Swarm) and ground-based (ionosondes, magnetometers, GPS/GLONASS receivers) data, allowing us to study PJ/SAID in detail and compare satellite data with ground-based measurements. We describe the characteristic patterns on ionograms that may indicate the presence of PJ/SAID and how ionosondes can be used to study PJ/SAID. Polarization Jet Strata and irregularities of plasma parameters can cause multiple reflections, which are visible in ionograms as F-spread. The splitting of the F2 trace into two or more traces on ionograms may indicate the presence of PJ/SAID near the observation point. Data from GPS/GLONASS receivers in regions where PJ/SAID is observed enable the construction of local total electron content maps, visualizing how PJ/SAID is reflected in those maps. It is shown how the geomagnetic latitude of PJ/SAID changes during the geomagnetic activity. Furthermore, this case is notable because not only PJ/SAID but also STEVE (Strong Thermal Emission Velocity Enhancement) is observed at subauroral latitudes in Northern Europe during the examined geomagnetic event.