The Sun’s Magnetic Field is about to Flip

Uh, why isn’t this bigger news?

A reversal of the sun’s magnetic field is, literally, a big event. The domain of the sun’s magnetic influence (also known as the “heliosphere”) extends billions of kilometers beyond Pluto. Changes to the field’s polarity ripple all the way out to the Voyager probes, on the doorstep of interstellar space.

When solar physicists talk about solar field reversals, their conversation often centers on the “current sheet.” The current sheet is a sprawling surface jutting outward from the sun’s equator where the sun’s slowly-rotating magnetic field induces an electrical current. The current itself is small, only one ten-billionth of an amp per square meter (0.0000000001 amps/m2), but there’s a lot of it: the amperage flows through a region 10,000 km thick and billions of kilometers wide. Electrically speaking, the entire heliosphere is organized around this enormous sheet.

During field reversals, the current sheet becomes very wavy. Scherrer likens the undulations to the seams on a baseball. As Earth orbits the sun, we dip in and out of the current sheet. Transitions from one side to another can stir up stormy space weather around our planet.

It’s probably not big news because even after reading the article I still have no idea how it actually impacts us on Earth and polarity reversal also happens ever 11 years.

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