edu.ucar.opensky::articles:16663 UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact 2025-12-26T03:11:55.839777 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) https://n2t.org/ark:/85065/d7jh3ndn The role of magnetic flux tube deformation and magnetosheath plasma beta in the saturation of the Region 1 field-aligned current system 2015-03-01T00:00:00Z publication https://n2t.org/ark:/85065/d7jh3ndn https://doi.org/10.1002/2014JA020533 Wilder, F. author Eriksson, S. author Wiltberger, Michael author UCAR/NCAR - Library publisher The phenomena of cross polar cap potential (CPCP) and ionospheric field-aligned current (FAC) saturation remain largely unexplained. In the present study, we expand upon the Alfvén wing model of CPCP saturation by investigating its impact on the magnetosphere-ionosphere current system, particularly the Region 1 FAC input into the polar cap. Our hypothesis is that the ability of open flux tubes to deform in response to applied fluid stress from the magnetosheath is governed by the magnetosheath plasma beta, which in turn governs the Maxwell stress imposed on ionospheric plasma from the magnetosphere. We performed 32 MHD simulations with varying solar wind density and interplanetary magnetic field strength and show that the plasma beta does govern the deformation of open field lines, as well as the nonlinear response of the Region 1 FAC system to increasingly southward interplanetary magnetic field. Further, we show that the current-voltage relationship in the ionosphere also shows a dependence on the plasma beta in the magnetosheath, with the ionosphere becoming more resistive at lower beta. UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact PDF Text theme Resource Type 2016-01-01T00:00:00Z publication Copyright 2015 American Geophysical Union. None eng geoscientificInformation