Pole Reversal

  • Released Tuesday, January 7, 2014
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Like a bar magnet, the sun has a magnetic north and south pole. The comparison to a simple bar magnet ends there, however, as the sun's magnetic fields are on the move. In fact, approximately every 11 years the polarity of the sun’s northern and southern hemisphere flips. This change is part of a regular cycle called the solar cycle. Each cycle is defined by periods of high and low solar activity caused by the movement of magnetic field lines that extend out from the sun. Now, a new animation created from data collected by the ESA/NASA SOHO spacecraft shows how migrating magnetic field lines result in a reversal of the sun’s polarity. Watch the video to see the evolution of the sun’s magnetic field from January 1997 to December 2013.

See the sun’s magnetic field do a flip.

See the sun’s magnetic field do a flip.

Lines colored magenta show where the sun's overall magnetic field is negative, and green where it is positive.

January 1997: A new cycle begins with positive polarity on top, and negative polarity on the bottom.

January 1997: A new cycle begins with positive polarity on top, and negative polarity on the bottom.

June 2003: Halfway through the cycle magnetic field lines are on the move.

June 2003: Halfway through the cycle magnetic field lines are on the move.

December 2013: The reversal of polarity is almost complete, with negative polarity on top, and positive polarity on the bottom.

December 2013: The reversal of polarity is almost complete, with negative polarity on top, and positive polarity on the bottom.

For More Information

See NASA.gov

Credits

Please give credit for this item to:
NASA's Goddard Space Flight Center

This page was originally published on Tuesday, January 7, 2014.
This page was last updated on Wednesday, May 3, 2023 at 1:51 PM EDT.