ANCHORAGE, Alaska (KTUU) – Most seasoned Aurora pursuers know there is a pattern for the aurora – an eleven-year solar cycle. When the solar cycle reaches its peak, the earth experiences many aurora. At least, sky watchers have less chance of seeing the northern lights. The last maximum was 2013. The sun is in its minimum.
Aurora on Bethel, April 20, 201
The phenomenon is the result of the magnetic field of the sun.
"Because the Sun is more a sphere of plasma than a solid object like Earth, the equator actually spins faster than the rest of the Sun," explains Erin Hicks, assistant professor of astronomy at the University of Alaska-Anchorage. As a result, the magnetic field of the sun, which is anchored in the plasma, twisted.
"We see more sunspots," says Hicks. "We are seeing more activity on the Sun, large piles of material that sometimes leaks into the solar system towards the earth and then it will settle down."
The Sun's minimum – that means fewer aura chances of seeing – is when the sun is magnetic The field settles down and moves more orderly.
Even when the sun approaches its solar minimum, this winter has a pretty good aurora. Hicks says that just because there are not so many massive explosions, there is still a steady stream of charged particles that hit Earth's atmosphere.
"The sun is still a very active body in our solar system," says Hicks. "For example, during this solar minimum, more steady streams of charged particles can come from the Sun. Although we do not have the big violent events that carry charged particles in our direction, there is still a steady stream, more of the solar wind effect."