Z. Kaymaz et al., INTERPLANETARY MAGNETIC-FIELD CONTROL OF MAGNETOTAIL FIELD - IMP-8 DATA AND MHD MODEL COMPARED, J GEO R-S P, 100(A9), 1995, pp. 17163-17172
Magnetic field patterns in the magnetotail's cross-sectional plane at
similar to 30 R(E) derived from IMP 8 data are compared with correspon
ding patterns derived from the Fedder-Lyon MHD model of magnetosphere
- solar wind interaction. The comparisons emphasize features attributa
ble to the influence of the interplanetary magnetic field (IMF). They
reveal considerable correspondences in field asymmetries, nonuniform f
ield perturbations, and current sheet twisting. Both data-based and MH
D-based patterns are qualitatively similar to patterns obtained by sup
erposing a uniform field on a dipole field, but they show that the fie
ld perturbations are stronger at the equatorial flanks of the tail tha
n in the high-latitude lobes. These quantitative details go beyond the
superposition model. From the point of view of interpretation, the fa
ct that the MHD-based patterns reproduce the distinctive nonsuperposit
ion features seen in the data-based patterns indicates that these feat
ures result from MHD motions within the magnetosphere distributing the
field that is merged at the magnetopause (i.e., the ''penetrating'' f
ield), From the point of view of modeling, the agreement indicates tha
t MHD modeling captures essential aspects of the solar wind - magnetos
phere coupling.