A Long, Quiet Solar Minimum
Published on Jul 11, 2008 at 3:21 pm.
17 Comments.
Filed under Sun.
My previous post was about how I’ve not been blogging much lately. The Sun’s been pretty quiet lately, too. In fact, there has been very little to look at on the Sun for a while. It has now been quite a long time since I’ve taken my students out to look at the Sun during the astronomy classes. The image above, courtesy of SOHO, is not just an orange circle. It is actually an image of the Sun. I know, it doesn’t look all that exciting. It’s not totally featureless, but it is far less impressive than images a few years ago. As I said, there hasn’t been much to look at for some time. For the last couple of years, there have frequently been no sunspots to observe. The lack of sunspots is a symptom of not much magnetic activity going on. Of course, for a lot of people, that is good, because lack of magnetic activity means that there is a low probability of a big solar flare and the accompanying radiation and geomagnetic storms. That means that satellites, power grids, communications, etc. don’t have to worry about disruptions due to solar activity.
But, is there something wrong with the Sun? Why are there no sunspots? A recent news story called attention to the fact that there have been no sunspots for a while. To discuss that, though, we need to first realize that the Sun does not have constant activity. For hundreds of years, astronomers have observed that sometimes there are more sunspots than at other times. Eventually, it became apparent that the Sun tends to build up activity to where it has a lot of spots, and then activity wanes until there are few, or even none. The Sun stays quiet like that for a while, and then activity picks up, and eventually the Sun’s face is routinely covered in spots again. The time that it takes for the Sun to go through this cycle is about 11 years, give or take a year. The Sun does not follow a set schedule, so some cycles are a little quicker than others, and some last a little longer. Below, courtesy of NASA, is a graphic showing solar sunspot activity for the last four centuries.
You notice that every decade, or so, Solar activity drops off. Sometimes it drops to near zero and hangs that way for a year or so. But, during an extended period of time in the late 17th Century, there were practically no sunspots at all for several decades. During this period of time, sunspots were the exception, rather than the rule. In fact, it was a big deal if an astronomer observed a sunspot then. We call this period of time the Maunder Minimum. But, sunspots are a symptom, not a cause, of solar activity. So, few sunspots means that the Sun itself is being pretty quiet. The Maunder Minimum also corresponds to a period of time when Earth’s climate was a bit screwy. In fact, in much of Europe (where we have the best weather records from the period), there was a general cooling — a period known as the Little Ice Age. The MSU press release that I cited above raises the specter that another Maunder Minimum event may be on the horizon.
However, let’s not be too quick to rush out and buy parkas. After all, the Sun is at solar minimum right now. It is supposed to be at a lull of sunspot activity. And, as I wrote a few months ago, the next sunspot cycle is already showing signs of getting started. It just takes a while. Today, an article at Science@NASA suggests that there is nothing at all wrong with the Sun. It may be that the current sunspot minimum is lasting a shade longer than average, but so what? An average is an average. By definition, there are times that are going to be longer and shorter than the average! What would be really be indicative of something being amiss would be if this minimum were lasting longer than at any time since the Maunder Minimum. But, that is not the case. There have been other minima lasting this long during the 20th Century. So far, the current minimum, though a little longer than average, is less than one standard deviation from the average length. You won’t need to start getting antsy until it is about two standard deviations late. Whenever anything is even slightly out of dead average, it seems that you always have somebody coming along claiming catastrophe is about to strike.
Interestingly, I read a novel a few years ago by Roger Zelazny and Thomas Thomas entitled Flare about the end of a Maunder Minimum type of event. It was quite an interesting read, and I recommend it. In the book, a Maunder Minimum started right at the beginning of the 21st Century, during which time humans moved forward in space exploration and colonization. Suddenly, sunspot activity began again, and all hell breaks loose. According to the book, the lack of activity from the Sun counteracted global warming due to greenhouse gases. Sadly, even if all the people who are convinced that the Sun is indeed about to go into a Maunder Minimum (which I doubt), evidence seems to be mounting that the current level of greenhouse gas emissions would more than make up for any cooling that might result. And, it is not even clear if events like the Little Ice Age are global or regional. So, just sitting around hoping that the current solar activity lull leads to an extended period of inactivity is a poor plan for dealing with global warming. And, indications are that this may be just the lull before the storm. Some solar researchers seem to be calling for an unusually active solar cycle about to happen.
-Astroprof
Images courtesy SOHO, NASA
Steven Long on July 11, 2008 at 4:43 pm: 1
Does that mean it could get even hotter? Oh I am so moving to Canada.
Mang on July 13, 2008 at 7:52 am: 2
When about might 2 standard deviations be?
Mang on July 13, 2008 at 7:55 am: 3
BTW. The comment code is not displaying. Fortunately I’d submitted one before and my browser remembered it.
Astroprof on July 13, 2008 at 11:55 am: 4
Thanks, Mang. I think that I fixed the verify code. If things don’t pick up by the end of next year, then we might start to wonder if the Sun were going into a quiet spell.
Consanescerion on July 24, 2008 at 12:49 am: 5
Mang: Three more months and we can begin to panic. Then we’ll be beyond 145 months. Average is 131 with a standard deviation of plus or minus 14 months. We’re at 142 now.
Jeff Corbin on August 10, 2008 at 7:58 am: 6
Farmers watch the refection of the sun on their crops. I grow fingerling potatoes in the Philadelphia Pa. I was completely unaware that a solar cycle existed until July 25, 2008 when my potatoes turned off 8-16 days early for no apparent reason. Looking for a reason, I learned all about the solar cycle and the fact we are in a deep extended Solar minimum. In particular, I found out through NOAA, that July 2008 solar activity dropped to very low levels in July 2008
Are there any studies which demonstrate the solar cycle in cycles of crop out put?
Astroprof on August 11, 2008 at 2:13 pm: 7
I don’t have the references at my finger tips, but I have read where there has been some correlation shown with wheat yields with the solar cycle. I’ve never heard of any research done on potatoes, but crops are way out of my area of specialty.
pittbull on August 12, 2008 at 6:49 am: 8
This silence is indeed disturbing but the way i see it it is the silence before something very bad happens.
Only the future will tell but i wouldn’t count on the maunder minimum i think some kind of maunder maximum is about to happen some kind of superflares. It has been observed that stars can get briefly more intense this has been noticed during long periods of observation of stars
They can become 100 times more intense during short periods!
We are in for a rough ride imagine what kind of radiation could be released at that point. Not to mention the temperature increase i think the poles are not going to melt but to boil!
Jeff on August 18, 2008 at 8:20 pm: 9
I’m not particularly worried about the somewhat atypical length of the current solar minimum. There are statistical studies, however, that may indicate a waning of solar activity over the next few decades. I wouldn’t be surprised if we have another multi-cycle minimum.
If it causes pronounced cooling, it may finally blow away the ridiculously unscientific Global Warming” hysteria, based on computer models that work approximately like slot machines.
Astroprof’s Page » A pregnant sun? on September 3, 2008 at 2:36 pm: 10
[…] This past month continued the unusually long period of extremely low solar activity that I had written about nearly two months ago. I’ll write more about the Sun’s unusual quiet period later, but […]
pitt bull on September 23, 2008 at 1:42 am: 11
at last a sunspot (1002)
hoera! no maunder minimum
Astroprof’s Page » A Sunspot! on September 24, 2008 at 4:14 pm: 12
[…] consequences to out of control production of greenhouse gases, that might not be a bad thing). I wrote about the solar minimum a while back. At that time, I did not think that the long solar minimum was […]
Astroprof on September 24, 2008 at 4:15 pm: 13
Thanks for the comment pitt bull. I had already planned on blogging about the new spot. I am glad to know that other people are out there keeping tabs on things.
pitt bull on September 27, 2008 at 1:57 am: 14
No problem
Always ready to track some sunspots.
pitt bull on September 30, 2008 at 12:15 pm: 15
Good news people 2 spots are emerging
follow the link
http://spaceweather.com/
pitt bull on October 14, 2008 at 12:15 pm: 16
Sorry forthe lag but it appears we are already at sunspot 1005!
http://spaceweather.com/
John A. Jauregui on October 26, 2008 at 11:58 pm: 17
If the reader would like to develop a better understanding of solar dynamics and why solar activity varies the way it does, and how this variability impacts our climate, google “solar inertial motion”. SIM for short. Also read up on an Aussie scientist by the name of Fairbridge.