Tuesday, June 14, 2011

Scientists Predicting A Quieter Sun

 

 

 

# 5629

 


Even as the sun slowly rouses itself from what has been an unusually long solar minimum, there are signs that long-term, our star’s sunspot activity may be moving into a period of relative quiescence.

 

Our sun is a variable star, and it goes through many major, and minor cycles. The best documented of these is the 11-year/22-year sunspot cycle.

 

Roughly every 11 years (it runs anywhere from 9 to 14 years), the sun experiences a magnetic pole shift at the time of solar maximum – a period of high sunspot and solar flare activity.

 

Every 22 years, the cycle completes, and the poles return to their `original’ position.

 

The next solar maximum was expected to peak next year, but the sun’s awakening has been running well behind schedule. Scientist now expect it may be 2013 before the next maximum occurs.

 

Today, three teams of scientists working independently are reporting to the annual meeting of The American Astronomical Society, being held this week at New Mexico State University, that there are signs that the solar-maximum-after-next (expected 2022-2023) may be much weaker than normal.


It may even disappear, and stay gone, for decades.

 

It has happened before.  

 

Between 1645 and 1715 there was a 70-year period known as the Maunder Minimum, where observable sunspots were all but absent on the sun’s surface.

image

 

From NASA.gov, this brief explanation of the Maunder event.

 

The Maunder Minimum

Early records of sunspots indicate that the Sun went through a period of inactivity in the late 17th century. Very few sunspots were seen on the Sun from about 1645 to 1715 (38 kb JPEG image). Although the observations were not as extensive as in later years, the Sun was in fact well observed during this time and this lack of sunspots is well documented.

This period of solar inactivity also corresponds to a climatic period called the "Little Ice Age" when rivers that are normally ice-free froze and snow fields remained year-round at lower altitudes. There is evidence that the Sun has had similar periods of inactivity in the more distant past. The connection between solar activity and terrestrial climate is an area of on-going research.

 


 

From Space.com we’ve more details on these three studies, each independently suggesting that the sun may be moving into a quieter phase.

 

Sun's Fading Spots Signal Big Drop in Solar Activity

by Denise Chow, SPACE.com Staff Writer

Date: 14 June 2011 Time: 01:01 PM ET

 

And more from PhysOrg.com

 

image

The Sun viewed in visible light, at minimum phase (2006) and maximum phase (2001)

 

What's down with the Sun? Major drop in solar activity predicted

 

 

(PhysOrg.com) -- A missing jet stream, fading spots, and slower activity near the poles say that our Sun is heading for a rest period even as it is acting up for the first time in years, according to scientists at the National Solar Observatory (NSO) and the Air Force Research Laboratory (AFRL).

 

As the current sunspot cycle, Cycle 24, begins to ramp up toward maximum, independent studies of the solar interior, visible surface, and the corona indicate that the next 11-year solar sunspot cycle, Cycle 25, will be greatly reduced or may not happen at all.

(Continue . . . )

 

 

 

Of course, we’ll have to wait to see if these models eventually play out the way these researchers are now expecting. It wasn’t so very long ago that scientists were predicting a potentially record-breaking Solar Maximum coming up in 2012.

 

A quieter sun wouldn’t necessarily be a bad thing. 


Solar flares and CMEs pose real dangers to satellites in orbit, passengers on the International Space Station, and even to our electrical grid on the earth’s surface (see A Flare For The Dramatic).

 

A prolonged quiet period, like we saw in the 1600s, might even serve to help cool the planet a bit.

 

How much of an impact all of this will have is going to have, I’m sure, will be the subject of much heated debate over the next few years. 

 

But whatever the end result, if this actually happens, it will provide scientists with invaluable data on how our sun, and our climate, interact.