Numerical Modeling of the Ring Current and Plasmasphere

摘要: Over the last 25 years, considerable scientific effort has been expended in development of quantitative models dynamics Earth's inner magnetosphere, particularly on studies injection storm-time ring current and dynamic variations shape size plasmasphere. Nearly all modeling ring-current agree that time-varying magnetospheric convection can produce approximately ion fluxes are observed current, but truth assumption never demonstrated conclusively. It is not clear actual electric fields strong enough to explain flux increases ~100 keV ions at peak current. Observational comparisons generally far from tight, primarily due paucity measurements basic limitations single-point observations. Also, most theoretical combine state-of-the-art treatment some aspects problem with highly simplified other aspects. Even sophisticated treatments sub-problems include substantial uncertainties, including following: (i) There still observational uncertainty about large-scale magnetosphere; (ii) No one ever calculated a force-balanced, time-dependent magnetic-field model consistent current; (iii) The obvious check overall realism would be compare its predicted Dst index against observations; however, calculations usually employ Dessler-Parker-Sckopke relation, which was derived dipole magnetic field cannot applied reliably conditions where plasma pressure significantly distorts field; (iv) Although loss rates by charge exchange Coulomb scattering reasonable accuracy, it remains unclear whether wave-induced precipitation plays an important role decay However, progress could made next few years. Spacecraft provide images large regions magnetosphere should eliminate much present ambiguity associated measurements. On side, will soon possible construct that, for first time, solve complete set equations entire magnetosphere. biggest calculation plasmasphere lies structure field. how interchange instability determining plasmapause or creating density fine structure.