Sun's Magnetic Field Almost Completely Reversed, Marking Midpoint of Solar Cycle 24 [VIDEOS]
The Sun's magnetic field is poised to completely flip, an event that happens every 11 years. Solar physicists began anticipating the reversal of polarity this summer, reporting in August that the reversal would be complete in the coming months. The polarity of the star's northern hemisphere already appears to have reversed and the southern hemisphere should be complete soon, scientists report.
"It's not a catastrophic event. It's a large-scale event that has some real implications, but it's not something you need to worry about," said Todd Hoeksema, a solar physicist at Stanford University's Wilcox Solar Observatory. "You've probably never even noticed it in the past. But technologically, we care more and more about it as time moves on."
While the internal mechanism that drives the switching of the magnetic field is not completely understood, researchers are able to identify the process as it occurs on the Sun's surface. Sunspots, areas of intense magnetic activity, appear as dark blotches on the surface of the Sun near its equator. Over about one month's time, the sunspots disintegrate and their magnetic activity migrates from the equator to one of the Sun's poles, eroding any existing and opposite polarity in its path, Hoeksema said in a news release. The magnetic field gradually recedes towards zero, then rebounds in the opposite polarity.
"It's kind of like a tide coming in or going out," Hoeksema said. "Each little wave brings a little more water in, and eventually you get to the full reversal."
The effects of the reversal of polarity will not be recognized by the average man on Earth, but the event will have ripple effects throughout the solar system, including a disruption of Earth magnetic field, which a variety of technologies we use depend on.
"The Earth's magnetic field is really important for lots of technological systems, things like power distribution grids, things like global positioning satellites, prospecting, that sort of thing," Hoeksema said in a video posted by Stanford.
"We also see the effects of this on other planets," Hoeksema said. "Jupiter has storms, Saturn has auroras, and this is all driven by activity of the Sun."
Watch Hoeksema explain more about the polarity reversal in the video below.
In this NASA Science video, the mechanics behind the solar cycle are explained.