NASA ScienceCasts: The Sun’s Magnetic Field is About to Flip [VIDEO]
The sun’s north and south poles are in the midst of flipping and reversing their magnetic fields, according to NASA-supported monitoring. The switch is part of a recurring Solar Cycle.
The current Solar Cycle 24 is the 24th solar cycle since 1755, when recording of solar sunspot activity began. It began on January 4, 2008. Approximately every 11 years the sun’s poles change polarity. The current flip in the sun’s polarity is the fourth time since scientists began monitoring the reversal of magnetic fields in the poles in the 1970’s.
“The sun’s north pole has already changed sign, while the south pole is racing to catch up,” says Scherrer, a solar physicist at Stanford University.” Soon, however, both poles will be reversed, and the second half of Solar Max will be underway.” Every 11 years on average the sun reaches a peak period of activity called “Solar Maximum” or “Solar Max” for short. This is followed 5-6 years later, by a period of relative quiet called “Solar Minimum”.
“It looks like we’re no more than three to four months away from a complete field reversal,” said solar physicist Todd Hoeksema, the Director of Wilcox Solar Observatory at Stanford University. The Wilcox Solar Observatory began daily observations of the Sun’s global magnetic field in May 1975, with the goal of understanding changes in the Sun and how those changes affect the Earth. These effects are called space weather.
“This change will have ripple effects throughout the solar system,” says Hoeksema. The sun’s magnetic influence extends some 8 billion miles through a region called the “heliosphere”. During the flip, the heliosphere – a massive magnetic sheet some 10,000 km thick and billions of miles wide extending outward from the sun’s equator – will become wavy. The wavy sheet will create cosmic “stormy weather”. The outermost boundary of our heliosphere, beyond Pluto, is where heliosphere meets interstellar space. Far beyond is the Oort Cloud, where comets travel around the sun, is the outer boundary of our solar system. When the sun’s polarity flips, the entire solar system will feel the effects of space weather, but most effect is contained within the heliosphere.
During Solar Max, sunspots and solar storms (solar flares, and coronal mass ejections) blast huge quantities of electromagnetic and particle radiation into the solar system. Sun storms can disrupt radio communications, compromise electrical power systems, damage sensitive satellite electronics, degrade satellite orbits, and cause errors in navigational equipment. Though, Earth’s atmosphere includes an invisible magnetic field, our magnetosphere, that shields our planet from most of the harmful effects of the radiation and plasma. Astronauts outside of Earth’s protective atmosphere or magnetosphere can be endangered by radiation from these events.