Numerical simulation of magnetospheric convection including the effect of field‐aligned currents and electron precipitation

摘要: Early results of a new self-consistent fluid model are presented for steady convection the plasma from geomagnetic tail through Earth's inner magnetosphere below 10 Earth radii (RE), including its coupling with ionosphere. This computes transport both ion and electron fluids constitutes an important improvement numerical Fontaine et al. (1985) (referred to as Paper 1), which simulated electrons only. The ionospheric is effected by precipitation magnetospheric electrons, enhances auroral conductivities, flow region 2 field-aligned currents, connect circuits. last was not considered in 1, because currents generated mainly pressure gradients that develop progressively during motion. We also take into account precipitation, affects generation but we neglect their relatively small effect on conductivities. devoted much effort produce description plasmas, couplings. As first step, order distinguish basic physical processes effects geometrical origin, solved equations case dipolar magnetic field 1. consequence, do expect our reproduce very precisely available observations rather provide only correct orders magnitude. solution scheme hyperbolic governing ions elliptic equation electrostatic potential, due basically same It makes use finite element method. run simulate evolution system initial state free plasma, situation has penetrated tail. Stable conditions corresponding Kp between 3 allow comparison observations. formation belt zone globally reproduced model, fluxes underestimated located equatorward regard DMSP satellite statistical current computed comparable observations, apart underestimation amplitude. structure found thus improving amplitude direction major component electric (the northward being at least 4 times larger than eastward component) consistent high latitude distribution incorrectly predicted. prevent penetrating midlatitudes induce rotation overall distribution. suggested rate under strong pitch angle scattering overestimated contributions conductances magnitude dusk sector.