OCTOBER 18-19, 1995 MAGNETIC CLOUD EVENT:
Modeling Ring Current Evolution
We study the passage at Earth of the October 1995 magnetic cloud
monitored by the
MFI
and
SWE
instruments on the GGS spacecraft WIND.
We simulate ring current development during the October 17-26 time interval
using our kinetic model and calculate the magnetic field perturbation
caused by the ring current. The plasma inflow on the nightside is
modeled according to measurements provided by the
MPA and
SOPA
instruments on the LANL geosynchronous satellites.
The modeled Dst index is compared with the observed Dst
values corrected for magnetopause and telluric currents.
The magnetopause currents are calculated following Burton et al.
[1975] and using dynamic pressure values derived from WIND/SWE data on
October 17-26, 1995.
The model predicts reasonably well the total ring current energy
variation during the storm period. The ring current buildup
resulting from convection alone could not account for the entire
decrease in Dst. An enhancement of plasma sheet
ion density was observed by LANL satellites during the storm period. We found
that this storm time enhancement in the plasma sheet ion density
contributed significantly to the ring current
formation.
References
Jordanova, V. K., C. J. Farrugia, L. Janoo, J. M. Quinn, R. B. Torbert,
K. W. Ogilvie, R. P. Lepping, J. T. Steinberg, D. J. McComas, and R. D.
Belian, October 1995 magnetic cloud and accompanying storm activity:
Ring current evolution,
J. Geophys. Res., 103, 79, 1998.
Questions? Comments? Please send e-mail to Vania Jordanova:
vania.jordanova@unh.edu
