A Self‐Regulating Equilibrium Magnetopause Model With Applications to Saturn. Issue 8 (29th August 2019)

• Record Type: Journal Article
• Authors: Hardy, F.; Achilleos, N.; Guio, P.
• Is Part Of: Journal of geophysical research. Volume 124:Issue 8(2019)
• Page Start: 6833
• Page End: 6849
• Publication Date: 2019-08-29
• Subjects: magnetopause -- pressure balance -- solar wind -- polar cusp -- Saturn; Magnetospheric physics -- Periodicals; Space environment -- Periodicals; Cosmic physics -- Periodicals; Planets -- Atmospheres -- Periodicals; Heliosphere (Astrophysics) -- Periodicals; Geophysics -- Periodicals; 523.01
• DOI: 10.1029/2019JA026751
• Languages: English
• ISSNs: 2169-9380

Abstract

Abstract: We describe a new method of constructing an equilibrium magnetopause surface based on the pressure balance between external and internal pressure sources. Details are given for every step of the procedure, including the initial pressure balance condition (which determines magnetopause morphology), the related underlying assumptions, and the final optimized magnetopause surface. Our method produces a final equilibrium magnetopause surface that satisfies the local balance between the solar wind dynamic pressure and planetary magnetic pressure with an error no greater than 1 % . We also discuss the contribution of hot plasma pressure and equatorial ring currents and their effects on magnetopause morphology. For each optimized magnetopause boundary, we give coefficients for fitted polynomial approximations to allow simple and accurate reproductions for practical applications. We specifically discuss the potential application to the modeling of Saturn's magnetopause and describe how the equilibrium magnetopause model can be used to estimate the compressibility of the boundary. Key Points: We construct a reference model of a planetary magnetopause based on pressure equilibrium We explain how the model provides realistic boundary features produced by the assumed structure of the magnetic field inside the boundary We describe cases of a pure dipole field, pure dipole field plus plasma pressure, and dipole plus plasma pressure and ring currents