Antarctic and Conjugate Research using SuperDARN

The Super Dual Auroral Radar Network (SuperDARN) is composed of high-frequency radars that can observe far reaches of the Earth's ionosphere, its features and irregularities, and monitor its dynamics. The ionosphere is an ionized layer in the upper atmosphere (at and above ~110-km altitude) where electrical currents can flow in response to the coupling between the Earth's magnetosphere and solar wind plasma flow in the Earth's neighborhood (geospace). Many geospace phenomena are caused by solar flares and coronal mass ejections that have their effects transmitted to ionospheric layers, which are especially strong in the polar regions. The ionospheric plasma convection (that carries ionospheric currents) becomes strong during geomagnetic storms when it moves as a whole over both polar caps from dayside to nightside and then returns to the dayside via respective auroral zones. Polar ionospheres are also electrically connected via the Earth's magnetic field lines in conjugate points. The ionospheric connection plays a very important role in transporting currents and electric fields between the magnetopause and both polar regions, but these processes are still insufficiently studied.

The large network of SuperDARN radars already observe ionospheric convection in the northern and southern polar regions on a regular basis. Data from these radars are used to study responses of ionospheric convection to solar wind and interplanetary magnetic field changes, the relation of central polar cap convection to that of the cusp and midnight regions, and to the state of the coupled magnetosphere-ionosphere system. The NSF-funded Antarctic SuperDARN radars at McMurdo and South Pole contribute to the studies such as relationships between wave structures observed in the solar wind and respective responses in the polar caps, motion of plasma density structures, ion-neutral coupling, and thermospheric winds. This research effort will continue developing the NSF-funded radars, help addressing fundamental questions of the Geospace research that have not yet thoroughly examined.