The Sun, the light at the centre of our solar system is fast approaching the end of its 11 year solar cycle. With the height of solar activity reached, the solar maximum, is it now time for our Sun to slumber?
NASA, not short of an opinion on all things scientific expect the current solar cycle to end mid-2013, while Japanese researchers armed with their own observations dispute NASA’s predictions. Suggesting instead that May this year will see the Sun’s pole shift, temporarily creating a quad pole magnetic field until the pole reversal completes and the next solar cycle begins.
An international research team led by Saku Tsuneta, a professor at National Astronomical Observatory of Japan (NAOJ) has been performing the monthly solar observations since September 2008, making use of Hinode, the Japanese solar observing satellite. Saku and his team of researchers have discovered that the sun’s pole shift will occur 12 months sooner than expected, May 2012.
The end of the solar cycle is signaled by a flipping of the magnetic poles of the Sun, the Sun then enters the Solar Minimum with solar flare activity dropping to its lowest point. During the pole shift the Sun may exhibit unusual activity including the appearance of 4 magnetic poles, 2 North and 2 South. Like a two headed chicken this is most unusual.
Even more incredible is the claim that, according to their observations, the Sun is currently exhibiting similar solar activity to that observed during the Maunder Minimum, which occurred during the coldest years of the Little Ice Age in the 17th century.
Solar flare activity is far easier to observe, than other solar processes, from the Earth’s surface. Solar observations actually date back as far back as the 17th century, enabled by the invention of the telescope. Giovanni Domenico Cassini and a team of observers in France collected many of the early observations, including those during the Maunder Minimum.
The Maunder Minimum occurred between 1645 and 1715 and is characterized as being a period with incredibly low levels of solar flare activity. During the 30 years in the middle of Maunder Minimum only 50 solar flares were observed, compared to the 40,000 to 50,000 that would be expected during a solar maximum.
There is still much to understand about the Sun and its solar flares, especially how they relate to the Earth and it’s weather. There is thought to be a connection between the Maunder Minimum and the Little Ice Age, lack of solar flare activity and the Earth’s cold periods. During the coldest years of the Little Ice Age (LIA), which occurred from 1350 to 1850 the Themes in London froze solid along with New York’s Hudson river, Manhattan become only an ice skate away. The great famine of 1315 marked a treacherous start to the LIA.
Several causes have been proposed for the LIA, cyclical lows in solar activity, a large number of volcanic events and changes to the oceans currents are the leading possibilities. Interestingly it is also possible that all three theories are intertwined, causing the cold event to last much longer than it otherwise would have.
Little is understood about the process of solar pole shift, only since the launch of solar observing satellites such as Hinode, along with NASA’s SOHO and SDO, have we been able to closely observe the process in action. This is the first end of a solar cycle observed with so mans mechanical eye’s in the sky. It may well be time to rug up and enjoy the solar show.