Polar Sun-Earth Connection Mission Data Archive at NASA/GSFC

The Polar spacecraft was launched on February 24, 1996, to obtain data from
both high- and low-altitude perspectives of this active region of geospace.
High above the poles the particles of the solar wind and the energy of the wind
can find their way into the magnetosphere. At lesser altitudes energy is
transferred from electric fields and electromagnetic waves to electrons that
then plunge into the atmosphere to create the aurora. At mid-altitudes nearer
the equator the satellite passes through the Earth's trapped radiation, the Van
Allen belts. Out of the polar ionosphere flows plasma to populate the
magnetosphere. Through this region particles and energy flow from the
geomagnetic tail to the atmosphere. Thus the instruments on the Polar
satellites see a lot of action in the various plasma parameters that they
measure.

Three of the twelve scientific instruments aboard the Polar satellite are used
to image the aurora in various wavelengths when the satellite is near apogee,
high over the northern polar region. The other nine instruments make
measurements in-situ, at the location of the satellite, around the entire
orbit. They measure the fluxes of charged particles, electrons and protons, as
well as heavier ions, from thermal energies into MeV energies. They measure
magnetic and electric fields, plus electromagnetic waves. They must make these
measurements in great detail in order for scientists to be able to learn new
things about the environment in the region over the poles of the Earth.

See:
http://pwg.gsfc.nasa.gov/polar/data_products.shtml
for a list of key parameters measured by the Polar mission.

Polar data for each instrument is available on ftp in compressed and
uncompressed form: ftp://pwgdata.gsfc.nasa.gov/pub/00readme.html

Processed science data is available from the NSSDC through the Space Physics
Data Availability Catalog (SPDAC)
http://spdf.gsfc.nasa.gov/SPD.html

ISTP Key Parameter data is available from the CDAWeb at NSSDC and CDAWeb
mirror sites:
http://cdaweb.gsfc.nasa.gov/

Data is also available from individual instrument teams through links
from the Polar Data Products page:
http://pwg.gsfc.nasa.gov/polar/data_products.shtml