Parameter Tree:
EARTH SCIENCE > SUN-EARTH INTERACTIONS > IONOSPHERE/MAGNETOSPHERE DYNAMICS

Definition:
Refers to dynamic processess of the Earth's ionosphere and solar magnetosphere
triggered by solar events. The magnetosphere is the magnetic cavity surrounding
the earth, carved out of the passing solar wind by virtue of the geomagnetic
field, which prevents, or at least impedes, the direct entry of the solar wind
plasma into the cavity. The ionosphere is the region of the earth's upper
atmosphere containing a small percentage of free electrons and ions produced by
photoionization of the constituents of the atmosphere by solar ultraviolet
radiation at very short wavelengths (l.t.1000 angstroms). The ionosphere
significantly influences radiowave propagation of frequencies less than about
30 MHz.


Reference:
NOAA/NGDC gloassary of solar-terresrial terms:
http://www.ngdc.noaa.gov/stp/GLOSSARY/glossary.html