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RealPlayer Windows Media
The Roots of the Sunspot Cycle
Magnetic-field model by Mausumi Dikpati, High Altitude Observatory/National Center for Atmospheric Research
The holy grail for solar scientists is to understand the sunspot cycle. Sunspot activity goes from minimum to maximum and back over a period of 11 years on average, though it ranges from 8 to 15 years. During this time, the sun's main magnetic field is reversing itself. The north pole becomes the south pole, then flips back during the next cycle. This computer model simulates the magnetic field reversal over two sunspot cycles. At solar minimum, the magnetic field is strongest near the poles (red). Solar max occurs when field strength is concentrated near the equator (blue), creating storms that can affect Earth. With such models, scientists are studying how the flow of plasma between the equator and the poles transports magnetic field lines. Computer modeling is helping scientists understand why the timing of the magnetic field reversal variesand may even help them predict when the next solar max will occur.
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