Lee Rannals for redOrbit.com — Your Universe Online
The sun is revving up and preparing for a new cycle next year, reaching solar maximum during the summer and fall months of 2013.
Our star goes through 11-year cycles, roughly. Some cycles can last as long as 14 years or as brief as nine. Despite what the cycle’s name suggest, solar storms could be mild during a solar maximum, or severe during a minimum.
The sun’s cycle is marked from minimum to minimum, making the maximum mark the halfway point through the cycle. Scientists are not certain why the cycles consistently last about 11 years, but they do understand the mechanisms that cause solar activity like solar flares and coronal mass ejections (CMEs).
The sun’s magnetic field is generated from within by the flowing motion of material. While Earth’s magnetic field is perpetuated by the churning of molten metal in the planet’s liquid outer core, the Sun’s magnetic field is produced by the movement of plasma.
Neither the Sun’s or the Earth’s magnetic fields are symmetric, stable or stationary. However, the Sun’s magnetic fields are more complex than Earth’s. The sun has many poles, with magnetic fields that constantly swell, bend and twist.
Over an 11-year cycle, the sun’s whole magnetic structure flips, helping to produce the solar activity that affects the rest of the solar system.
This solar activity includes differential rotation, plasma and magnetic fields. Differential rotation means that the sun rotates at different speeds and directions at different latitudes and depths.
“They get all twisted up inside,” C. Alex Young, a solar astrophysicist and associate director of science for the Heliophysics Science Division at NASA´s Goddard Space Flight Center, wrote in Earth Magazine. “It´s like the rubber band on a balsa wood airplane – you twist the rubber band until it starts to knot up.”
A single sunspot has a magnetic strength that is thousands of times greater than earth’s entire magnetic field. These spots can last for days or weeks. The magnetic field lines that cause sunspots get twisted up, reconfiguring themselves and releasing energy. This release of energy is what produces light in the form of a solar flare, or a CME.
Solar flares are a brief flash of electromagnetic radiation, while a CME is a billion tons of solar plasma and magnetic field, according to Young. CMEs can travel millions of miles per hour and they typically take two to three days to reach earth.
The largest CME to ever hit earth occurred in 1859 and it disrupted the telegraph system at the time. With today’s technology, a CME of that nature could bring on a lot more damage to our everyday lives than what took place over 150 years ago.
In 1972, a CME caused a geomagnetic storm that took out phone lines in Illinois, and an event in 1989 melted power transformers in New Jersey and knocked out power for most of Quebec.
Scientists can be more prepared than ever before now, with the spacecraft we have orbiting to help us detect solar activity. NASA’s SOlar and Heliospheric Observatory (SOHO), Solar TErrestrial RElations Observatory (STEREO) and Solar Dynamics Observatory (SDO) are all instruments that can be used by scientists to prepare us for these storms.
Another instrument, the Advanced Composition Explorer (ACE), was placed into space in 1997, and it is the whistleblower for scientists to help determine when a CME is headed towards earth. ACE is equipped with nine sensors and instruments to help with these predictions.
ACE can help scientists provide 20 to 60 minutes of warning before impact, which could help astronauts working in space pursue safety precautions, and warn power grid operators that their systems could be overloaded.
While scientists know that solar maximum is just around the corner, and have systems in place to help warn us Earthlings of this space weather, it is still too early to tell what exactly the Sun’s new cycle means for us. Regardless, man is prepared better than ever before for what the sun has to offer us next year.