Testing the Validity of Inner-magnetosphere Shielding by the Region-2 Field-aligned Currents

Virginia Polytechnic Institute And State University, Blacksburg VA

Investigators

Abstract

The outer layers of the Earth's atmosphere interact with the solar wind. Scientists still do not understand the process of how energy is transported from the solar wind throughout each of these layers of low-density, plasmas. This work investigates how these energy transport processes occur from the magnetosphere into the ionosphere. The project is relevant to the National Space Weather Action Plan since it will assist in identifying typical limits of ionospheric disturbances generated from extremes of observed space weather effects. These disturbances affect the orbits of satellites that can compromise tracking and operations of our US commercial and defense assets. An early career scientist and undergraduate researchers will be supported. The shielding electric field generated due to charge separation associated with the Region-2 Field Aligned Currents (FAC) plays an important role in determining the dynamics of the coupled inner magnetosphere-ionosphere system. However, the paucity of global-scale measurements of field-aligned currents and electric fields in the sub-auroral region has restricted our understanding of the dynamics of inner magnetosphere shielding and several questions remain unanswered. Specifically, (1) To what extent is the paradigm of shielding valid?, (2) What are the timescales associated with shielding?, and (3) How do season and local time influence shielding? The overarching goal of this work is to answer these questions by using measurements from the NSF-funded Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) dataset to determine the imbalance between the Region-1 and Region-2 FACs as a proxy for the intensity of shielding. Specific tasks will focus on combining AMPERE FACs with electric fields from the mid-latitude Super Dual Auroral Radar Network (SuperDARN) to determine the extent to which the paradigm of inner magnetosphere shielding by Region-2 FACs is valid and to determine the modulating influence of ionospheric conductivity and MLT on the magnitude, extent and timescales of over-/under-shielding electric fields. 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.