Solar Storms, Geomagnetic Storms and Auroras: Effects on TodayÕs Technologies

James L. Green


The sun's heliosphere, extending to large distances into space is the region
where the solar wind and solar magnetic field exits.  Solar plasma (ionized
matter) extends far beyond the photosphere or visible surface of the Sun in,
what is referred to as, the solar atmosphere. Streaming from the solar
atmosphere the sun constantly loses ionized matter called the solar wind. In
addition to the electromagnetic radiation from the sun, the solar system is
constantly bathed in the solar wind.  The solar wind consists of mostly
high-speed protons and electrons constantly escaping from the Sun.  The steady
solar wind is continually modified with the introduction of high velocity matter
coming from the sun from solar flares and coronal mass ejections. The region
where the EarthÕs magnetic field exists is called the magnetosphere. Under most
conditions the Earth's magnetosphere provides a significant protection pushing
the solar wind around it.  However, under certain circumstances the protection
of the magnetosphere dramatically breaks down allowing the solar wind to flow
in, and by mixing with magnetospheric plasmas, cause geomagnetic storms and
impressive auroral displays.  It is during these times that spacecraft and
ground-based power grid systems are the most vulnerable.

______________
Brown Bag Seminar, Goddard Space Flight Center, June 7, 2006