Comprehensive Study of 3D Magnetosphere-Ionospheric Current System Through the Modeling, Observations, and Applications: Auroral Electrojet Indices for the Southern Hemisphere

Catholic University Of America, Washington DC

Investigators

Abstract

The Earth's three-dimensional magnetosphere-ionosphere current system is an important component of the Geospace environment. These currents are driven by the interaction of solar wind (an everlasting plasma flow from the Sun) with the Earth's magnetosphere, transferring significant amounts of energy and momentum into the high-latitude ionosphere and upper atmosphere via the geomagnetic field-aligned currents. The 3D current system dynamics affect both the Northern and South Polar Regions, causing their dynamic changes and heating through the closure of these currents in the Earth's ionosphere. These currents can be modeled, but they are difficult to observe from the ground or even from space - only their effects on geomagnetic field variations (and respective indices of geomagnetic activity) can be recorded by properly placed ground-based instruments. This award will support a study of a relatively unexplored phenomenon of interhemispheric field-aligned currents through the model development and comparison of modeled results with the ground-based and satellites observations. This new model will significantly advance our understanding of the physics of space weather-driving processes in both hemispheres and development of an index describing geomagnetic activities in the Southern polar region. The latter is important because calculating this index using existing Aural Electrojet (AE) technique (that uses data from 12 geomagnetic observatories across the Northern auroral region) is not applicable to the Southern auroral region that goes over Southern Ocean for ~50% of the global coverage. There are only 5-6 Antarctic costal research stations that can contribute to this index calculations, which is much less than optimal for the traditional AE calculation technique. This research effort has the potential to significantly increase our understanding of the role played by interhemispheric currents on the dynamics of the polar and auroral regions. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.