Abstract
The correct stability criterion of interchange motions in the magnetosphere has been a question of some controversy. Many researchers hold the view first espoused by Gold [1959]. For a low‐β plasma in a dipole magnetic field, Gold argued that the gradient of pVγ, where p is the plasma pressure, V is the unit flux tube volume, and γ is the adiabatic polytropic index, determines the interchange stability. This notion was further developed by Chandrasekhar [1960]. This common belief was questioned by Cheng [1985], who was subsequently questioned by Rogers and Sonnerup [1986] and Southwood and Kivelson [1987] on the issue. Is Gold's criterion the necessary and sufficient condition for interchange stability? We shall demonstrate that the answer is “no” and provide a more accurate criterion for the dipole magnetic field. We shall also discuss the interchange instability in a plasma distribution with a longitudinal gradient.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
