On October 18-20, 1995, GEOTAIL was traversing the dayside magnetosheath/SW and experienced repeated encouters with the bow shock and magnetopause. WIND was upstream monitoring the solar wind input to the magnetospheric system.
Figure GT_MGFEFD_951018_951020 shows the electric field and magnetic field data from GEOTAIL for the period of interest. The Probe_A data indicate the reverse of the probe potential in volts and is proportional to the density of the plasma weighted by the squareroot of the temperature. Constant Probe_A indicates fairly steady SW conditions. The magnetic field data are in GSM coordinates. The electric field data (mV/m) are in GSE coordinates. The last quantity is the X-component of the flow velocity of the plasma that is perpendicular to the magnetic field direction. Values of ~250 km/s are seen throughout most of the time the SC is in the SW.
The following figures show the GEOTAIL magnetic field and plasma data for the event as measured from the MGF and LEP instruments on GEOTAIL. The data are provided by the ISAS team in their web page: http://www.gtl.isas.ac.jp. They are reproduced here to facilitate the GEM studies. Each plot represents an 8 hour interval. There are three plots per day. The color spectrograms can be found at the aforementioned ISAS site.
GT_MGFLEP_951018.01...... GT_MGFLEP_951018.02...... GT_MGFLEP_951018.03
GT_MGFLEP_951019.01...... GT_MGFLEP_951019.02...... GT_MGFLEP_951019.03
GT_MGFLEP_951020.01...... GT_MGFLEP_951020.02...... GT_MGFLEP_951020.03
Similar pages for the benefit of the scientific community that can be useful for the above study have been created by L. A. Frank at the University of Iowa and have been placed on the web site: http://www-pi.physics.uiowa.edu/www/cpi/. They are reproduced here from that site, again, for facilitating this GEM study. The two, 5-day period figures correspond to measurements from the Hot Plasma analyzer (HP) and the Solar Wind analyzer (SW).
Significant information can be gained from the energetic particle instrument on GEOTAIL. Twelve hour plots from that dataset have been constructed by the PI and co-I's of the EPIC team (D. J. Williams, R. W. McEntire) and have also been placed on the WEB for the benefit of the community at: http://sd-www.jhuapl.edu/Geotail/. The relevant plots for the event of interest from the EPIC instrument dataset are shown below (two plots per day).
EPIC_951018_A...... EPIC_951018_B
EPIC_951019_A...... EPIC_951019_B
EPIC_951020_A...... EPIC_951020_B
