DOI: 10.5061/dryad.v6wwpzh23
title: Supporting materials and data from: Hypotheses concerning global magnetospheric convection, magnetosphere-Ionosphere coupling, and auroral activity at Uranus

description: Summary: The data and figures contained in this dataset are
 supporting materials for the paper referenced in the title and abstract
 below.  This study involved an analytical and numerical
 assessment of the Uranian magnetosphere and its interaction with the solar
 wind and interplanetary magnetic field (IMF). The data and figures
 contained in this dataset include supplementary results for a greater
 number of IMF orientations and Uranian seasons than the examples presented
 in the corresponding paper. Abstract from corresponding paper:
 doi:10.1029/2023JA031791 with Journal of Geophysical Research Space
 Physics:We investigate the unique magnetosphere of Uranus and its
 interaction with the solar wind. Following previous work, we developed and
 validated a simple yet valuable and illustrative model of Uranus’ offset,
 tilted, and rapidly-spinning magnetic field and magnetopause (nominal and
 fit to the Voyager-2 inbound crossing point) in three-dimensional space.
 With this model, we investigated details of the seasonal and
 interplanetary magnetic field (IMF) orientation dependencies of dayside
 and flank reconnection along the Uranian magnetopause. We found that
 anti-parallel (magnetic field shear angle greater than 170-degrees)
 reconnection occurs nearly continuously along the Uranian dayside and/or
 flank magnetopause under all seasons of the 84 (Earth) year Uranian orbit
 and the most likely IMF orientations. Such active and continuous driving
 of the Uranian magnetosphere should result in constant loading and
 unloading of the Uranian magnetotail, which may be further complicated and
 destabilized by sudden changes in the IMF orientation and solar wind
 conditions plus the reconfigurations from the rotation of Uranus itself.
 We demonstrate that unlike the other magnetospheric systems that are
 Dungey-cycle driven (i.e., Mercury and Earth) or rotationally driven
 (Jupiter and Saturn), global magnetospheric convection of plasma, magnetic
 flux, and energy flow may occur via three distinct cycles, two of which
 are unique to Uranus (and possibly also Neptune). Our simple model is also
 used to map signatures of dayside and flank reconnection down to the
 Uranian ionosphere, as a function of planetary latitude and longitude.
 Such mapping demonstrates that “spot”-like auroral features should be very
 common on the Uranian dayside, consistent with observations from Hubble
 Space Telescope. We further detail how the combination of Uranus’ rapid
 rotation and unique and very active global magnetospheric convection
 should be consistent with fueling of the surprisingly intense trapped
 radiation environment observed by Voyager-2 during its single flyby.
 Summarizing, Uranus is a very special magnetosphere that offers new
 insights on the nature, complexity, and diversity of planetary
 magnetospheric systems and the acceleration of particles in space plasmas,
 which might have important analogs to exoplanetary magnetospheric systems.
 Our hypotheses can be tested with further work involving more advanced
 models, new auroral observations, and unprecedented missions to explore
 the in situ environment from orbit around Uranus, which should include a
 complement of magnetospheric instruments in the payload. 
description: See the corresponding paper for description of the model that was
 used to generate these results. These movies and graphics and table all
 correspond to simulations of Uranus' interaction with the solar wind
 and estimates of reconnection along the dayside and flank magnetopause of
 the Uranian magnetosphere system. Also included are movies and graphics
 estimating auroral activity in the ionosphere at Uranus. All results are
 dependent on Uranian season (soltices, equinoxes, and mid-seasons), solar
 wind magnetic field vector (IMF), and diurnal (spin) phase. Also included
 are results supporting the validation of the model tested on Earth's
 magnetosphere. General descriptions of the various files are included in
 the README file.
description: The files and data contained here are in a series of figures
 (.pdf format), movies (.mp4 format), and excel spreadsheets.