To investigate the contributions of the release of energy stored in the
magnetosphere and of direct solar wind energy/momentum flux to the
cause of auroral storms and substorms. Space and ground based
measurements are used in the AMIE analysis procedure to derive the
global distribution of field aligned currents, the major coupling
parameter between the magnetosphere and ionosphere. (Several other
ionospheric parameters are obtained concurrently.) AMIE/TIEGCM also
derives global ionospheric conductances, providing boundary conditions
for magnetospheric models. The time/space evolution of ionospheric
parameters throughout a substorm has not previously been investigated
with a global high resolution data set which is provided by GGS
The experiment should be carried out when the apogee
of POLAR is in the northern hemisphere during winter
months, i.e. Oct. 96 to Feb. 97. A three day interval
should be scheduled to accommodate two scenarios,
1) the occurrence of a substantial substorm lasting
3 to 5 hours, and 2) waxing and waning of auroral
activity during a magnetically active period. For
advanced planning the 3-day interval may be chosen
based on the 27 day recurrence of solar/geomagnetic
POLAR DATA REQUIRED
UVI, VIS and PIXIE are the prime instruments for the
experiment. On UVI, filters LBHshort and LBHlong
should alternate at 1 min. repetition rate.
VIS should have the 391.4 nm filter throughout the
dark segments of the 3 day period, also at 1 min.
data rate. The 1 minute data acquisition/readout
intervals should be synchronized.
POLAR De-Spun PLATFORM OPERATIONS
VIS and UVI always pointing toward north polar
region of Earth. Angle adjusted to ensure full
view of auroral oval by both imagers as much as is
possible in an orbit.