Sun Magnetic Flip

Sun magnetic flip

Very good video: http://www.space.com/22264-sun-s-magnetic-field-will-soon-flip-stormy-space-weather-ahead-video.html

The sun's magnetic field changes polarity approximately every 11 years.  It happens at the peak of each solar cycle as the sun's inner magnetic dynamo re-organizes itself.  The coming reversal will mark the midpoint of Solar Cycle 24 (The sun has been quiet during its current 11-year activity cycle, which is known as Solar Cycle 24. ) . Half of 'Solar Max' will be behind us, with half yet to come.
The sun's polar magnetic fields weaken, go to zero, and then emerge again with the opposite polarity. This is a regular part of the solar cycle."
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.
The part of the sun's magnetic field that's set to shift is often called the "current sheet." It's the surface that juts out from the sun's equator, which carries a small electrical current.

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.
Cosmic rays are also affected. These are high-energy particles accelerated to nearly light speed by supernova explosions and other violent events in the galaxy.  Cosmic rays are a danger to astronauts and space probes, and some researchers say they might affect the cloudiness and climate of Earth. The current sheet acts as a barrier to cosmic rays, deflecting them as they attempt to penetrate the inner solar system. A wavy, crinkly sheet acts as a better shield against these energetic particles from deep space.
This polarity flip is perfectly normal solar behavior, occurring every 11 years at the peak of our star's activity cycle. But the field reversal doesn't drive the increase in solar flares and eruptions of superheated plasma, called coronal mass ejections, that is observed around solar max. - Scientist claims


From a human perspective, the effects of the field shift will likely be slight and primarily beneficial. For example, the polarity reversal will cause the "current sheet" — an enormous surface extending out from the solar equator on which the sun's rotating magnetic field has induced an electric current — to become much wavier.

This crinkled current sheet will provide a better barrier against galactic cosmic rays, high-energy particles that are accelerated to nearly the speed of light by faraway star explosions. Galactic cosmic rays can damage spacecraft and hurt orbiting astronauts, who don't enjoy the protection of Earth's thick atmosphere.

"One of the things that helps clouds form and lightning to flash is cosmic-ray ionization of things in the Earth's atmosphere," Hoeksema told Space.com. "So when the cosmic-ray intensity is lower, it means you have fewer places where lightning will occur, and so the storms will probably be a little less intense."

The only issue related to the flip of the sun's magnetic field is that it corresponds with the peak of the sunspot cycle, when the sun is prone to launch flares and bursts of plasma into space that can affect satellites and power grids.

The sun isn't the only body in the solar system with a magnetic field that reverses. Earth has a magnetic field as well, and it has flipped many times over the last billion years. The magnetic fields of both the sun and the Earth are thought to be generated by similar "dynamo" processes that involve rotating and convecting electrically conducting fluids—molten iron in the case of the Earth and hot, ionized gases for the sun.The difference, however, is that Earth's magnetic field reversals happen much less frequently—only once every 200,000 to 300,000 years on average.



Sunspot cycle:
The number of sunspots observed on the "surface" of the Sun varies from year to year. This rise and fall in sunspot counts varies in a cyclical way; the length of the cycle is around eleven years on average. The cyclical variation in sunspot counts, discovered in 1843 by the amateur German astronomer Samuel Heinrich Schwabe, is called "the Sunspot Cycle".
11-year Sunspot Cycles
Ever since the astrophysicist John Eddy pointed out in 1976 that the "Little Ice Age" occurred within a period of reduced sunspot activity, the search has been on for evidence that a variable Sun controls climate. The original idea was that sunspot cycles influence climate on an 11-year cycle, a concept explained in a book by Hoyt and Schatten (1997), The Role of the Sun in Climate Change .

Sunspots are huge magnetic storms that show up as darker regions on the sun�s surface. They tend to occur in cycles, with the number and size reaching a maximum approximately every 11 years. During periods of maximum sunspots the sun emits more energy (about 0.1 percent more) than during periods of sunspot minimums. Apparently bright spots that form around the sunspots radiate more energy, thus offsetting the effect of the dark spots. Note, however, that the energy difference is very small, amounting to approximately one tenth of the total effect that increasing levels of greenhouse gases have had on warming the atmosphere to date.
The luminosity of the Sun increases a little when there are sunspots.
The number of sunspots reaches a maximum about every 11 years, but successive maxima have spots with reversed magnetic polarity.