Bibcode
Xie, H.; Lin, Y.; Perez, J.
Referencia bibliográfica
American Geophysical Union, Fall Meeting 2001, abstract #SM41B-0799
Fecha de publicación:
12
2001
Número de citas
0
Número de citas referidas
0
Descripción
A 2-D global hybrid simulation is carried out to study the structure of
the dayside magnetopause in the noon-midnight meridian plane associated
with magnetic reconnection. In the simulation the bow shock,
magnetosheath, and magnetopause are formed self-consistently by
supersonic solar wind passing the geomagnetic field. The reconnection
events at high- and low-latitudes are simulated for various IMF
conditions. To assure the validation of the applied spatial resolution,
we also compare this global-scale simulation with our previous 2-D
hybrid simulations for the local magnetopause structure near the X line
and the simulation of the corresponding 1-D Riemann problem. The
following results will be presented. (1) Large-amplitude rotational
discontinuities and Alfvén waves are present in the quasi-steady
reconnection layer. (2) The rotational discontinuity possesses an
electron sense, or right-hand polarization in the magnetic field as the
discontinuity forms from the X line. Later, however, the rotational
discontinuity tends to evolve to a structure with a smallest field
rotational angle and thus may reverse its sense of the field rotation.
The Walén relation is tested for electron and ion flows in the
magnetopause rotational discontinuities with left-hand and right-hand
polarizations. (3) The structure of the magnetopause discontinuities and
that of the accelerated/decelerated flows are modified significantly by
the presence of the local magnetosheath flow. (4) Field-aligned currents
are generated in the magnetopause rotational discontinuities. Part of
the magnetopause currents propagate with Alfvén waves along the
field lines into the polar ionosphere, contributing to the field-aligned
current system in the high latitudes. (5) Finally, typical ion velocity
distributions will be shown at various locations across the magnetopause
northward and southward of the X lines. The ion distributions associated
with single or multiple X lines will be discussed. The transmission and
reflection rates of the magnetosheath particles have also been
calculated.