Solar Cycle Driven by More than Sunspots; Sun Also Bombards Earth with High-Speed Streams of Wind
From an NCAR press release September 17, 2009
BOULDER—Challenging conventional wisdom, new research finds that the number of sunspots provides an incomplete measure of changes in the Sun’s impact on Earth over the course of the 11-year solar cycle. The study, led by scientists at the High Altitude Observatory of the National Center for Atmospheric Research (NCAR) and the University of Michigan, finds that Earth was bombarded last year with high levels of solar energy at a time when the Sun was in an unusually quiet phase and sunspots had virtually disappeared.
“The Sun continues to surprise us,” says NCAR scientist Sarah Gibson, the lead author. “The solar wind can hit Earth like a fire hose even when there are virtually no sunspots.”
The study, also written by scientists at NOAA and NASA, is being published today in the Journal of Geophysical Research – Space Physics. It was funded by NASA and by the National Science Foundation, NCAR’s sponsor.
Scientists for centuries have used sunspots, which are areas of concentrated magnetic fields that appear as dark patches on the solar surface, to determine the approximately 11-year solar cycle. At solar maximum, the number of sunspots peaks. During this time, intense solar flares occur daily and geomagnetic storms frequently buffet Earth, knocking out satellites and disrupting communications networks.
(Illustration by Janet Kozyra with images from NASA, courtesy Journal of Geophysical Research – Space Physics.) click for larger image”]
Gibson and her colleagues focused instead on another process by which the Sun discharges energy. The team analyzed high-speed streams within the solar wind that carry turbulent magnetic fields out into the solar system.
When those streams blow by Earth, they intensify the energy of the planet’s outer radiation belt. This can create serious hazards for weather, navigation, and communications satellites that travel at high altitudes within the outer radiation belts, while also threatening astronauts in the International Space Station. Auroral storms light up the night sky repeatedly at high latitudes as the streams move past, driving mega-ampere electrical currents about 75 miles above Earth’s surface. All that energy heats and expands the upper atmosphere. This expansion pushes denser air higher, slowing down satellites and causing them to drop to lower altitudes.
Scientists previously thought that the streams largely disappeared as the solar cycle approached minimum. But when the study team compared measurements within the current solar minimum interval, taken in 2008, with measurements of the last solar minimum in 1996, they found that Earth in 2008 was continuing to resonate with the effects of the streams. Although the current solar minimum has fewer sunspots than any minimum in 75 years, the Sun’s effect on Earth’s outer radiation belt, as measured by electron fluxes, was more than three times greater last year than in 1996.
Gibson said that observations this year show that the winds have finally slowed, almost two years after sunspots reached the levels of last cycle’s minimum.
The authors note that more research is needed to understand the impacts of these high-speed streams on the planet. The study raises questions about how the streams might have affected Earth in the past when the Sun went through extended periods of low sunspot activity, such as a period known as the Maunder minimum that lasted from about 1645 to 1715.
“The fact that Earth can continue to ring with solar energy has implications for satellites and sensitive technological systems,” Gibson says. “This will keep scientists busy bringing all the pieces together.”
Buffeting Earth with streams of energy
 Sarah Gibson [ENLARGE](©UCAR, photo by Carlye Calvin.) News media terms of use* |
For the new study, the scientists analyzed information gathered from an array of space- and ground-based instruments during two international scientific projects: the Whole Sun Month in the late summer of 1996 and the Whole Heliosphere Interval in the early spring of 2008. The solar cycle was at a minimal stage during both the study periods, with few sunspots in 1996 and even fewer in 2008.
The team found that strong, long, and recurring high-speed streams of charged particles buffeted Earth in 2008. In contrast, Earth encountered weaker and more sporadic streams in 1996. As a result, the planet was more affected by the Sun in 2008 than in 1996, as measured by such variables as the strength of electron fluxes in the outer radiation belt, the velocity of the solar wind in the vicinity of Earth, and the periodic behavior of auroras (the Northern and Southern Lights) as they responded to repeated high-speed streams.
The prevalence of high-speed streams during this solar minimum appears to be related to the current structure of the Sun. As sunspots became less common over the last few years, large coronal holes lingered in the surface of the Sun near its equator. The high-speed streams that blow out of those holes engulfed Earth during 55 percent of the study period in 2008, compared to 31 percent of the study period in 1996. A single stream of charged particles can last for as long as 7 to 10 days. At their peak, the accumulated impact of the streams during one year can inject as much energy into Earth’s environment as massive eruptions from the Sun’s surface can during a year at the peak of a solar cycle, says co-author Janet Kozyra of the University of Michigan.
The streams strike Earth periodically, spraying out in full force like water from a fire hose as the Sun revolves. When the magnetic fields in the solar winds point in a direction opposite to the magnetic lines in Earth’s magnetosphere, they have their strongest effect. The strength and speed of the magnetic fields in the high-speed streams can also affect Earth’s response.
The authors speculate that the high number of low-latitude coronal holes during this solar minimum may be related to a weakness in the Sun’s overall magnetic field. The Sun in 2008 had smaller polar coronal holes than in 1996, but high-speed streams that escape from the Sun’s poles do not travel in the direction of Earth.
“The Sun-Earth interaction is complex, and we haven’t yet discovered all the consequences for the Earth’s environment of the unusual solar winds this cycle,” Kozyra says. “The intensity of magnetic activity at Earth in this extremely quiet solar minimum surprised us all. The new observations from last year are changing our understanding of how solar quiet intervals affect the Earth and how and why this might change from cycle to cycle.”
About the article
Title: “If the Sun is so quiet, why is the Earth ringing? A comparison of two solar minimum intervals”
Authors: Sarah Gibson, Janet Kozyra, Giuliana de Toma, Barbara Emory, Terry Onsager, and Barbara Thompson
Publication: Journal of Geophysical Research – Space Physics
Related sites on the World Wide Web
Whole Heliosphere Interval (2008)
h/t to Leif Svalgaard
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Leif adds some perspective to this press release:
IMHO this is just another PR stunt, ‘never seen before’, ‘overturns what we thought before’, etc.
It has been known for a long time [decades] that there are strong recurrent solar wind streams leading up to solar minimum [EVERY solar minimum]. Attached are plots of the solar wind speed prior to minimum for many minima in the past. The blue curve show the speed derived from geomagnetic measurement and the pink curve shows that directly measured by spacecraft, some of the differences between the curves is due to missing data from the spacecraft [at times they only measured a small percentage of the time]. The smooth curves are 13 rotation running means.Also attached is the Recurrence Index, a measure for the recurrence tendency of the flow. High values = a solar rotation is very much like the previous one [the cross correlation between the two]
Especially the minimum in 1944 is very much like the current one in the sense that there was high-speed solar wind close to the minimum, even closer, fact. It is amazing that each new generation of scientists will have to rediscover and relearn what was already known. But such is human nature, every generation has to do this.
ralph (03:52:46) :
Do you believe that the Maunder and Dalton minimums were colder epochs?
Here are two reconstructions of Temperature [top] and Solar Output [bottom]: http://www.leif.org/research/Loehle-Temps-and-TSI.png
I see no clear match.
Scott 3:12:24
Just as I ask David B. Benson if the title of Spencer Weart’s new book will be ‘The Discovery of Global Cooling’ so I ask if Chris Moody’s new book about the EPA and/or Cap and Trade will be ‘The Democrats’ War on Science’.
Back to schuul, boys and girls; don’t guess, look it up.
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Ralph,
Please consider that the appearance of colder temperatures when there was the Maunder and Dalton minimums only suggests that the sun had anything to do with temperatures. Just like an increase in CO2 along with an increase of temperatures has ‘settled’ the science for so many people using these time periods to prove that this is what drives temperature is foolish. Currently we are experiencing a lull in the Sun’s activity without seeing a large correlation thus far with temperatures. How many spotless days have we had and what has been the temperature response to date? This does not mean that temperature will not respond it simply means that while the theory that the minimums are linked with temperature there is no more concrete evidence of that then there is to link CO2 to the temperature. Honestly the climate system is really complex and while the sun is the main provider of energy it is also not varying enough ( or at least in a way we can correlate to date ) to cause major temperature fluctuations.
What does this boil down to… Just realize that it is easy to fall into the same trap that people who believe CO2 is the primary cause of climate change when it is an insignificant marker ( at least seems to be to date ) that the same thing can occur while trying to explain the recent warming and attributing it to other things like the sun. The point of being a skeptic is to think logically through the situation and notice fallacies. The moment you start talking about amplifications ( feedback ) you start sounding just like the people who advocate CO2 as the main climatic driver over the last 150 years.
This does not mean you do not present theories but do not simply embrace a theory because it seems to fill the void on something you have concluded cannot be the answer ( CO2 is not the main culprit for instance )
Lief, thanks for all the writing you do on this blog, it is always a joy to dip into your knowledge of the sun. Based on your understanding of the sun what would have to happen in order to cause a change in temperature on the earth either positive or negative? Is direct radiation the only known mechanism? Thanks again.
Leif, sorry for misspelling your name noticed it once I posted…
Too much “pathos” (passion) in this sun issue, better we cool it down. Too many ions around?
Dr. Svalgaard, I appreciate your contributing to this website where those of us who have science backgrounds, but are not expert in such fields as solar science can learn and help to wade through the tons of marginal or “junk” science that we see so much of in the climate change debate. Your comments on the release of this paper and your reference to prior work done, apparently ignored by the authors, raises a troubling question: Is the scientific peer review process so corrupted that authors such as these can get away with passing off their work without reference to prior work? If so, what can be done about it? Would appreciate any comment you might have on this.
Leif, in your post at 07:21:50, your temp reconstruction doesn’t match very well with your solar activity reconstruction. I’m looking to see if I can get the graphic for Judith Lean’s 10Be and 14C isotopic record for cosmic ray variation, e.g. a proxy for solar activity as it affects the troposphere and land. In the meantime, please look at the 14C graphic (“Solar Events in 14C”) in Wikipedia, and see if perhaps that doesn’t better match the temperature reconstruction. And I’ll keep looking to see if I can find the Lean graphic.
http://en.wikipedia.org/wiki/Solar_variation
At least someone recognises that changes in the Sun do have an impact on Earth. It’s some kind of progress ….
Peter Taylor (06:53:38)
“I think the cloud effects, if real, would readily transmit to the oceans and create a signal, with some time-lags due to currents and storm track shifts.”
Reply:
Reduced cloudiness would indeed allow more solar energy to hit the oceans and increase energy in the water with the consequences you mention.
My problem is in deciding whether the cloudiness changes drive ocean energy content changes or whether the oceans vary the rate of energy release to the air and thus drive cloudiness changes.
The oceans being liquid and in constant movement at all levels I find it hard to envisage that they always provide a steady flow of energy to the air. It seems inherently improbable given the hugely greater energy capacity of water as against air.
Then there is the matter of timing. There is no correlation with the 25 to 30 year ocean phase changes for any events in the air whether related to solar cycles or cosmic ray levels.
Furthermore we always see air temperature changes and latitudinal air circulation shifts AFTER changes in sea surface temperatures. Never before.
As I’ve said to Erl Happ on another thread I see this as a critical issue in discrediting AGW because if changes in the air alone cannot alter the background rate of energy flow from the oceans then AGW is falsified but there is an unfortunate side effect that sceptical air based ideas are also rendered implausible.
The reason is that if one cannot alter ocean temperatures by changing something in the air alone and we can see that air temperatures are always governed by sea surface temperatures then what happens instead is a change in the rate of energy flow from surface to space which has the potential to neutralise any extra energy in the air from more GHGs or from any other cause.
Well said.
One such fallacy is the AGW crowd’s notion that a lack of credible alternatives makes AGW more likely correct. So that invites people to show “credibility” towards alternatives. All a bit pointless.
Don´t want to increase “voltage” but this press release has been cited also under a different perspective, here:
http://www.thunderbolts.info/tpod/00current.htm
Leif, here is a link to a 1996 article written by J Lean and D Rind which shows low levels of 10Be and 14 C during the Sporer and Maunder minima. It is from the US climate change research program information office. The article has a useful graphic showing solar activity during the Sporer and Maunder minima; it isn’t the specific graphic I was looking for, but it is close enough:
http://www.gcrio.org/CONSEQUENCES/winter96/article3-fig2.html
Here is the text about this graph, from the article:
“What we know of the connection between solar activity and radiation, coupled with high abundances of isotopes in tree-rings and ice-cores (Fig. 2d), supports the likely case that during the Maunder Minimum solar activity remained for over half a century at very low levels.”
The graph and text comes from this article:
http://www.gcrio.org/CONSEQUENCES/winter96/sunclimate.html
Leif, I’ve found a graphic from a Judith Lean/David Rind article which shows low solar activity, as marked by variations in 10Be and 14 C during the Sporer and Maunder minima. Here’s a link the the article:
http://www.gcrio.org/CONSEQUENCES/winter96/sunclimate.html
And a link to the graphic itself:
http://www.gcrio.org/CONSEQUENCES/winter96/article3-fig2.html
Figure 2 (d) is the one to look at.
And here is the text about the graph:
“What we know of the connection between solar activity and radiation, coupled with high abundances of isotopes in tree-rings and ice-cores (Fig. 2d), supports the likely case that during the Maunder Minimum solar activity remained for over half a century at very low levels.
The present production of terrestrial 14C and 10Be appears to be near historically-low levels, due to persistently high solar activity that inhibits the rate at which these isotopes are produced. The same isotopic records show that the Sun seems to have been building up over the last several hundred years to a state of enhanced activity that is the opposite of the suppressed levels of the 17th century Maunder Minimum. From this we might expect that solar radiation is also approaching levels last seen in the 12th century Medieval Maximum. Still, any extrapolation of future changes in the long-term behavior of the Sun is highly uncertain, since we are as yet unable to make accurate predictions of the level of solar activity in even the next eleven-year cycle, which will reach a maximum in about the year 2000. “
some years ago I remember NASA recording that the solar constant had increased from the 19th century. It was reported on the BBC site then though can’t fnd it now in the archives. It inferred that this alone was enough to have caused the 20th century’s warming. The best I can find is:
http://www.giss.nasa.gov/research/news/20030320/
Mark (05:44:30) :
re, Leif (02:35:37:
“Yet America [or more precisely USA] is also the place were an almost equal percentage believes that the Earth is only 6000 years old.”
I can’t believe you said this Leif. Not only is it grossly wrong, it’s a stereotype spewed forth by many rabid warmers and extreme leftists.
Next time your in the USA, do an informal poll of your own. I bet you’ll find less than 1 out of 100 believes it.
Mark, he says it quite often, and it reduces his credibility. I’m 100% Agnostic, and I don’t even use that ignorant statement against the believers. There’s only a very small segment of Americans (er, USA) that believes in the strict, literal interpretation of the Bible, and that’s the Jehovah’s Witnesses. But when you discuss this with them, they’re very clear on their response: The mistranslation of units of time.
I’ll just leave it at that.
It’s amazing how the intelligent among us can be so ignorant sometimes.
@ur momisugly kim (07:26:51) :
Just as I ask David B. Benson if the title of Spencer Weart’s new book will be ‘The Discovery of Global Cooling’
Why would Spencer Weart write about something that is not happening? There is no global cooling.
re Bruckner8 (08:47:46);
This is the first time I’ve heard him say this. If he has used it before, then you’re right, it shows ignorance.
That’s too bad because I find solar physics interesting and think it’s rather cool that he occasionally stops by here to inform us and get in on discussions.
I understand, Scott, theat the concept of an increasing solar constant is quite a confounding idea, ie, its not so constant. However, if its provided the greater part of warming in the 20thC, then surely solar inconstancy can also force a cooling climate.
http://www.giss.nasa.gov/research/news/20030320/
Peter Taylor (06:53:38) :
4) How does the magnetic field of a star transmit the mechanical energy of angular momentum from its satellites – as astrophysicists believe is the case
Nice analysis, and nice question!
I have done some calcs on ocean heat content and looked at rates of oceanic heat/energy accumulation and dissipation and devised a method for reconstucting Earth’s temperature history from sunspot and magnetic data.
Leif confirmed my OHC calcs as correct but unconvinced by my oceanic heat retention theory.
Nicola Scafetta has advised me to publish (and no doubt be damned) 🙂
I hope Leif takes the trouble to answer your post.
Mike Bryant (05:36:08) :
I wonder if it is these simple-minded people who are the reason we still have our freedom.>
Mark (05:44:30) :
Next time your in the USA, do an informal poll of your own. I bet you’ll find less than 1 out of 100 believes it.
I actually live in the US. I lived many years in Texas and I can tell from personal experience [friends and neighbors] that the percentage I quoted is not far off. Also, see Mike’s post above.
John (05:44:50) :
possibility remains that over a long period such as the Maunder Minimum, the solar wind might indeed have been relatively weak for many decades.
We know that there still was a solar modulation of cosmic rays and reconstructions of the magnetic field during the MM show almost the same value as today, so the evidence for a significant downturn is weak.
Scott A. Mandia (05:52:35) :
What is your position on how much of a role the sun has had in the climate change observed since the Industrial Revolution?
What role do you think human greenhouse gas emissions have had?
My opinion is ‘not much’ for both.
tallbloke (05:57:03) :
Fascinating. So would assymetry in higher latitude coronal holes between northern and southern solar hemispheres influence the ‘flatness’ (notwithstanding the ‘waviness’) of the heliospheric current sheet?
There are some people that think so. Google ‘bashful ballerina’
TJA (06:16:16) :
ralph, I am a skeptic, and don’t buy some of the stuff that Leif is selling but “If the answer is yes, then these colder episodes were clearly linked to lower Sunspot activity, ” is just not a logical statement in any sense. It is rhetorical, and nobody every proved a scientific fact with rhetoric.
Couldn’t have said it better meself. On the other hand, you convince the average Joe [the Plummer] with rhetoric, not science.
Peter Taylor (06:53:38) :
you will see trough 22 is about 35% greater than trough 20. There is then a 15% recovery during cycle 23.
Those variations ride on top of a large background. The GCR variation is only a few percent of the total flux and 35% of a few percent still ain’t much.
I would argue it is unwise to dismiss solar-cloud or any solar-climate correlations
It is the other way around, proponents have to demonstrate their efficiency. It is unwise to act on those before such clear demonstration.
1) I heard that the Earth’s magnetosphere has recently developed a large ‘hole’ – does this mean that plasma can come in?
Pure PR stunt. There are no holes. The solar wind magnetic field connects with the Earth’s every few hours [or even minutes at times] as it has done for billions of years. This allows the two regimes to interact.
2) Was the gamma ray burst of solar or galactic origin?
Neither. It came from a very distant source far, far outside our Galaxy.
3) Was there anything unusual about the sun when the Carrington event occurred? How does the sun’s status then compare to today?
Not that we know of [and Carrington has left us very detailed observations for years before and after the event]. The Carrington event could happen today [well perhaps in a few years, when we get some spots]
4) How does the magnetic field of a star transmit the mechanical energy of angular momentum from its satellites
It doesn’t, but the magnetic field does transfer angular momentum to the solar wind [magnetic field lines have tension in them – try to move opposite magnetic poles apart and you’ll see] and as the solar wind is lost from the solar system [eventually] this process brakes solar rotation slightly. That is why the Sun rotates so slowly [25 days], compared to very young stars that rotate in a day or so.
kim (07:03:00) :
And there’s a big fat logical fallacy sitting in your insinuations to Frank Lansner at 2:35:37. Can you find it?
No, as I didn’t draw any logical conclusions.
kim (07:11:19) :
I’m just trying to keep you off that thin ice.
And I was just relaying a personal observation.
Innocentious (07:38:02) :
what would have to happen in order to cause a change in temperature on the earth either positive or negative? Is direct radiation the only known mechanism?
A very important mechanism is the orbital elements of the Earth: distance to the Sun, obliquity, season of perihelion, etc. Those are likely the direct causes of the glaciations we have had in the past [and will have in the future]. What the Sun does is but a tiny wiggle on top of that and has to compete with variations in ocean circulation, volcanoes, etc.
Regards Maunder and Dalton minimums.
>>>but “If the answer is yes, then these colder episodes were
>>>clearly linked to lower Sunspot activity, ” is just not a logical
>>>statement in any sense.
>>>Currently we are experiencing a lull in the Sun’s activity
>>>without seeing a large correlation thus far with temperatures.
If you believe that the Maunder epoch was colder, then there must be a mechanism for that. A likely candidate has to be the equivalent lack of Sunspots in that era. The Sun is, after all, the sole provider of weather and climate on the Earth.
If you don’t believe that Sunspots and solar activity were involved, then perhaps you could present an alternate hypothesis. I am all ears.
As to the current Sunspot minimum not producing lower temperatures, I would beg to differ. The long upward drift of global temperatures has abated. Likewise, it is fairly axiomatic that a large body of water, like that contained in the oceans, would act as a huge accumulator of energy. Any cooling is likely to involve a considerable time lag.
.
Doug Ferguson (08:26:04) :
Is the scientific peer review process so corrupted that authors such as these can get away with passing off their work without reference to prior work? If so, what can be done about it?
If the ‘peers’ don’t know any better…
The real fault is with the PR people that issue misleading and over-hyped press releases. Take them out back and shoot them 🙂
Stephen Wilde (08:33:26) :
i>I see this as a critical issue in discrediting AGW
The goal of research should not be to discredit anybody, but to find out how things work.
John (08:43:57) :
In this business a decade is a long time. The variations in TSI that Lean used are way obsolete. The real variations are much smaller.
Modern reconstructions of both temperature and solar activity:
http://www.leif.org/research/Loehle-Temps-and-TSI.png
P Wilson (08:46:06) :
some years ago I remember NASA recording that the solar constant had increased from the 19th century.
modern reconstructions do not show any such increase.
Mark (09:03:10) :
That’s too bad because I find solar physics interesting and think it’s rather cool that he occasionally stops by here to inform us and get in on discussions.
The literal interpretation of the Bible is not restricted to Jehovah Witnesses [as Googling “young earth” will show], and I think the ignorance bit is with the ‘young Earth’ crowd.
With respect to the “6000 year old Earth” belief percentage, it seems to have it’s roots in an interpretation of Gallup poll results which dealt with questions related to belief in the biblical interpretation of man’s origin, rather than a specific belief in a 6000 year old Earth. The percentage of people in the US who believe in the literal truth of such a young Earth would be far lower. This is discussed here: http://www.michaelpatrickleahy.com/column_042207_biglie.html
Once again Stephen, I have to comment on your clarity of thought and what seems to me to be a wonderfully logical mind. You are to the oceans what Leif is to the Sun. 4 marks.
Leif:
‘bashful ballerina’
Hmmmmm, interesting. 🙂
Thanks Leif, you truly are a mine of interesting information.