Solar proton events produce several major consequences at Earth:
Minutes to Hours Later .....
Solar protons are accelerated to very high velocities in the explosive release of energy associated with a solar flare. These particles first make their way out of the corona. Then they cannot take a straight line path to the Earth but must travel along the Sun's extended magnetic field lines (called the interplanetary magnetic field or IMF). These field lines have a structure resembling the spiral traced out by a spinning lawn sprinkler, which is referred to as a Parker spiral.
The image on the right shows how flare location on the surface of the Sun affects the intensity and arrival time of the high speed solar particles at the Earth. In the first case, the flare occurred in the center of the Sun on a direct line-of-sight path to the Earth. In the second case, the flare site is on the limb of the Sun, directly connected to the Earth along a curved magnetic field line. The line plot in each case gives the history of the flux (in logarithmic units) as it arrives at Earth. The flare particles, blown out at the limb of the Sun, arrive more rapidly and in greater numbers (flux is almost 10 times higher) than those that began their journey from the center of the solar disk.
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