Space science research from Antarctica - Antarctica: Global Science from a Frozen Continent - page 217

Figure 7.5 Above approximately 60 km, ultraviolet radiation and solar X-rays

from the Sun ionise the upper atmosphere creating an ionised (charged) gas
that is called a plasma. In the ionosphere, since individual particles are
electrically charged, currents can flow and radio waves can be re ected
enabling long-distance radio communication.

drops by a factor of about a thousand at the boundary of the
plasmasphere the plasmapause.

The radiation belts comprise regions of intense

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fluxes of much
higher energy charged particles than those that exist in the
plasmasphere. These high energy charged particles are con ned by

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Earth field. The intensities of these trapped particles can

change with time under disturbed solar conditions, and it has even
been found in the last decade or so that a third electron belt can
occasionally form under very severely disturbed conditions. The
process by which this can occur is unknown. Sensitive electronics in
orbiting spacecraft can be affected, and even damaged, by radiation
belt particles. The ionised particles in Earth

s magnetic

s magnetotail can be
accelerated in energy under disturbed solar conditions, and these
particles can be driven into the upper atmosphere, causing and
enhancing auroral displays. In addition, these accelerated particles
can be added to the radiation belt populations.

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Solar - terrestrial research in Antarctica

The Antarctic has a number of important advantages for studies of
space-related phenomena, both solar terrestrial research as well as

astronomical research. In terms of solar

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terrestrial research, several
geographic and geomagnetic features make the Antarctic the

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rst
choice for important research. These include (1) the large land mass;
(2) a wide expanse in coverage of both geographic and geomagnetic
latitudes at all longitudes; (3) the foregoing item (2) derives directly
from the fact that the highest latitude magnetic

fields lines, those
that can connect to the boundary of the magnetosphere and to the
interplanetary medium, are measurable in the Antarctic while in the
northern hemisphere this location is over the ocean; (4) the southern
geomagnetic dipole on the land mass and the southern geomagnetic
pole is very close to the land mass; (5) the high elevation of the
South Pole (and other Antarctic locations) for optical studies (also
applicable to some astronomical studies); (6) the wide range of areas