Proposed Priority Science Operations Topic
Topic 1: 'Auroral Acceleration Region'
TOPIC DESCRIPTION
Background:
Polar will regularly sample the auroral field lines below ~12,000 km
where energetic auroral acceleration processes transfer keVs of energy
to electrons and ions. Previous missions such as S3-3, DE-1 , Viking
and Akebono have sampled this region with limited coverage in altitude,
energy, mass and velocity space. The data returned from these missions
were inadequate to clearly distinguish among many theoretical explan-
ations for the explosive transfer of energy to ions and electrons in
this region.
Polar will for the first time provide simultaneous, fully three
dimensional velocity distributions for all major species with time
resolution of a few seconds in conjunction with a full set of plasma
wave measruments from DC to above AKR emissions. Simultaneous solar
wind data will always be available from WIND. These data will provide
an opportunity to make signficant progress in our understanding of these
magnetosphere-ionosphere coupling phenomena. They will be further
enhanced by simultaneous observations from the FAST satellite.
Science Investigation:
We want to acquire a coordinated set of in-situ plasma particle and
field measurements and ground based measurements from both the southern
hemisphere (SESAME) conjugate hemisphere during several intervals when
the POLAR spacecraft samples the plasma on auroral field lines below
altitudes of 15,000 km, with particular, but not exclusive, interest in
night-side auroral field lines.
EPOCH/ORBIT CHARACTERISTICS
POLAR at an altitude less than 15,000 km
Auroral field lines with particular interest on the
nightside.
Above an invariant latitude of 45 degrees.
SPECIAL POLAR DATA REQUIRED
CAM: emphasis on H+/He++/and O5+, O6+ and O7+.
CEP: Highest time resolution data for electrons
and He++
EFI: Highest time resolution and snapshot mode
HYD: Highest time resolution electrons
MFE: Normal 8.3 V/s mode
PIX: Center image on foot of field line
PWI: Wideband coverage of low frequence part of
spectrum including lower hybrid frequency.
TID: High time resolution H+ and O+ over the
full energy range
TIM: Same as TID
UVI: Images centered on foot of field line
VIS: Images (visible preferred,otherwise UV)
centered on foot of field line
SPECIAL DESPUN PLATFORM OPERATIONS
Preferably foot of field line containing POLAR.
OTHER ISTP REQUIREMENTS
WIND: solar wind monitoring
PACE: operational to acquire as much high latitude
data as possible
CANOPUS: If conjugate, operate.
Topic Proposed by: E. G. Shelley
e-mail: shelley@agena.spasci.com