摘要
A new magnetopause model is proposed based on observation results, in which the magnetic-field includes one constant component and one monotomcally increasing component, so that magnetic field shear exists during the intervals when the interplanetary magnetic field has a northward component. Under this model, a completely analytical self-consistent equilibrium distribution function is derived based on the Vlasov-Maxwell equations. Through the analysis of this distribution function and its moments, the following can be concluded: (i) The equilibrium distribution function consists of a homogeneous Maxwellian distribution and two inhomogeneous shifted-Maxwellian distributions. There are "hole" and "bump" structures which have different cross-field drift velocities in the velocity distribution, (ii) The density decreases monotonously from the outside of the magneto-pause to the inside, (iii) The electrical current distribution is a typical current sheet structure, (iv) Under a certain condition of
A new magnetopause model is proposed based on observation results, in which the magnetic-field includes one constant component and one monotomcally increasing component, so that magnetic field shear exists during the intervals when the interplanetary magnetic field has a northward component. Under this model, a completely analytical self-consistent equilibrium distribution function is derived based on the Vlasov-Maxwell equations. Through the analysis of this distribution function and its moments, the following can be concluded: (i) The equilibrium distribution function consists of a homogeneous Maxwellian distribution and two inhomogeneous shifted-Maxwellian distributions. There are 'hole' and 'bump' structures which have different cross-field drift velocities in the velocity distribution, (ii) The density decreases monotonously from the outside of the magneto-pause to the inside, (iii) The electrical current distribution is a typical current sheet structure, (iv) Under a certain condition of temperature parameters, the thickness of the magnetopause may be larger than the ion gyroradius. These results are applicable to the region of the low-latitude magnetopause during the intervals when the interplanetary magnetic field has a northward component.
基金
Project supported by the National Natural Science Foundation of China.
