TY - JOUR

T1 - Modeling of twisted/warped magnetospheric configurations using the general deformation method

AU - Tsyganenko, NA

PY - 1998/10/1

Y1 - 1998/10/1

N2 - A new method is developed for modeling the effects of the planetary dipole tilt and of the interplanetary magnetic field (IMF) related twisting of the cross-tail current sheet. The method extends the field deformation technique of Stern [1987] and makes it possible to easily represent a wide variety of warped magnetospheric configurations, starting from simple models with an axially symmetric magnetopause and a planar tail current sheet. The proposed transformations do not violate the condition del.B = 0 and allow one to retain a desired distribution of the normal component of the total field at the magnetospheric boundary. Furthermore, the method makes it possible to add flexibility to the model magnetopause, so that the effects of the dipole tilt and of the IMF upon its shape can be reproduced. In particular, the transformation with a radially dependent rotation of the X and Z axes, while providing the desired tilt-related bending of the cross-tail current sheet, can also deform the magnetopause and reproduce its tilt-related asymmetry, indicated by observations and reported here for the first time. The deformation technique also allows algorithms that are more compact and faster than the currently used ones. Because of the general nature of the proposed approach it should be possible to extend it to the modeling of other (e.g., Jovian) planetary magnetospheres.

AB - A new method is developed for modeling the effects of the planetary dipole tilt and of the interplanetary magnetic field (IMF) related twisting of the cross-tail current sheet. The method extends the field deformation technique of Stern [1987] and makes it possible to easily represent a wide variety of warped magnetospheric configurations, starting from simple models with an axially symmetric magnetopause and a planar tail current sheet. The proposed transformations do not violate the condition del.B = 0 and allow one to retain a desired distribution of the normal component of the total field at the magnetospheric boundary. Furthermore, the method makes it possible to add flexibility to the model magnetopause, so that the effects of the dipole tilt and of the IMF upon its shape can be reproduced. In particular, the transformation with a radially dependent rotation of the X and Z axes, while providing the desired tilt-related bending of the cross-tail current sheet, can also deform the magnetopause and reproduce its tilt-related asymmetry, indicated by observations and reported here for the first time. The deformation technique also allows algorithms that are more compact and faster than the currently used ones. Because of the general nature of the proposed approach it should be possible to extend it to the modeling of other (e.g., Jovian) planetary magnetospheres.

KW - MAGNETOSPHERE

KW - TAIL

KW - MAGNETOPAUSE

KW - DIPOLE

KW - GEOMAGNETIC FIELD

KW - CURRENT SHEET

U2 - 10.1029/98JA02292

DO - 10.1029/98JA02292

M3 - Article

VL - 103

SP - 23551

EP - 23563

JO - Journal of Geophysical Research: Biogeosciences

JF - Journal of Geophysical Research: Biogeosciences

SN - 0148-0227

IS - A10

ER -