On the equilibrium of the magnetopause current layer

A numerical study was made of the confinement of a uniform magnetic field by a warm plasma with a net velocity parallel to the confined field. Parker's assumptions of a vanishing electric field and vanishing trapped-particle currents and pressures were adopted. For a given proton temperature equilibriums were found whenever the electron temperature exceeded a certain critical value. This result is in qualitative agreement with an estimate presented by Parker, but it is in direct conflict with Lerche's nonexistence proof. A crucial error in that proof is identified. The properties of the equilibrium solutions are discussed. Finally, the equilibrium confinement with the incident streaming plasma tangential to the magnetopause but perpendicular to the confined field is treated. It is concluded that in the geomagnetic equatorial plane equilibriums of Parker's type are possible on the morning side but not on the afternoon side of the magnetosphere.