"Sunspots are related to geomagnetic storms, because when the sun has more sunspots, more [solar storms] occur," Norton said. "But it is not as simple as [noting that] if there is a large sunspot, a storm will occur."
Sunspots appear as dark patches, because they are cooler than other regions on the surface of the sun. The temperature differences are caused by intense magnetic fields, which suppress convective motions that transport heat out toward the sun's atmosphere.
"Sunspots are believed to be small pieces of much larger magnetic field residing in the solar interior," Norton said.
Scientists believe sunspots emerge like loose loops of thread, known as flux ropes, from the larger magnetic field inside the sun. The intersection of the thread with the solar surface (think of a rainbow touching the horizon) creates a sunspot pair.
Sunspots occur in cycles of increasing and decreasing activity that last approximately 11 years. The last sunspot cycle peaked in 2000. The next cycle is expected to begin in 2005 or 2006.
Current research suggests that sunspots with complex magnetic geometries, such as twists and shears, culminate in solar storms, which are known as coronal mass ejections and solar flares.
During a storm, magnetic clouds of charged particles are ejected into space. Sometimes Earth intercepts these clouds, which affect Earth's magnetic field and the surrounding environment.
"Charged particles saturate and deform the configuration of Earth's magnetic field," Norton said. "This induces current in power lines, causing large-scale power outages. When satellites experience direct hits from charged particles, they can be damaged and lose communication abilities."
If constructed, ATST may provide further details on the conditions that give rise to solar storms, allowing researchers to make more informed weather forecasts.
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