Sun said to be “bi-modal”
While many, including the IPCC, suggest the modern Grand Maximum of solar activity from 1950-2009 has nothing to do with the 0.4C global warming measured over that time frame, it does seem to be unique in the last three millennia.
from CO2 Science: A 3,000-Year Record of Solar Activity
What was done
According to Usoskin et al. (2014), the Sun “shows strong variability in its magnetic activity, from Grand minima to Grand maxima, but the nature of the variability is not fully understood, mostly because of the insufficient length of the directly observed solar activity records and of uncertainties related to long-term reconstructions.” Now, however, in an attempt to overcome such uncertainties, in a Letter to the Editor published in the journal Astronomy and Astrophysics, Usoskin et al. “present the first fully adjustment-free physical reconstruction of solar activity” covering the past 3,000 years, which record allowed them “to study different modes of solar activity at an unprecedented level of detail.”
What was learned
As illustrated in the figure below, the authors report there is “remarkable agreement” among the overlapping years of their reconstruction (solid black line) and the number of sunspots recorded from direct observations since 1610 (red line). Their reconstruction of solar activity also displays several “distinct features,” including several “well-defined Grand minima of solar activity, ca. 770 BC, 350 BC, 680 AD, 1050 AD, 1310 AD, 1470 AD, and 1680 AD,” as well as “the modern Grand maximum (which occurred during solar cycles 19-23, i.e., 1950-2009),” which they describe as “a rare or even unique event, in both magnitude and duration, in the past three millennia.”
Further statistical analysis of their reconstruction revealed the Sun operates in three distinct modes of activity – (1) a regular mode that “corresponds to moderate activity that varies in a relatively narrow band between sunspot numbers 20 and 67,” (2) a Grand minimum mode of reduced solar activity that “cannot be explained by random fluctuations of the regular mode” and which “is confirmed at a high confidence level,” and (3), a possible Grand maximum mode, but they say that “the low statistic does not allow us to firmly conclude on this, yet.”
What it means
Usoskin et al. (2014) write their results “provide important constraints for both dynamo models of Sun-like stars and investigations of possible solar influence on Earth’s climate.” They also illustrate the importance of improving the quality of such reconstructions, in light of the fact that previous reconstructions of this nature “did not reveal any clear signature of distinct modes” in solar activity.
Unfortunately, it was beyond the scope of this paper to address the potential impact of solar activity on climate. Yet the reconstruction leaves a very big question unanswered — What effect did the Grand maximum of solar activity that occurred between 1950 and 2009 have on Earth’s climate? As a “unique” and “rare” event in terms of both magnitude and duration, one would think a lot more time and effort would be spent by the IPCC and others in answering that question. Instead, IPCC scientists have conducted relatively few studies of the Sun’s influence on modern warming, assuming that the temperature influence of this rare and unique Grand maximum of solar activity, which has occurred only once in the past 3,000 years, is far inferior to the radiative power provided by the rising CO2 concentration of the Earth’s atmosphere.
Reference
Usoskin, I.G., Hulot, G., Gallet, Y., Roth, R., Licht, A., Joos, F., Kovaltsov, G.A., Thebault, E. and Khokhlov, A. 2014. Evidence for distinct modes of solar activity. Astronomy and Astrophysics 562: L10, doi: 10.1051/0004-6361/201423391.
Abstract
Aims. The Sun shows strong variability in its magnetic activity, from Grand minima to Grand maxima, but the nature of the variability is not fully understood, mostly because of the insufficient length of the directly observed solar activity records and of uncertainties related to long-term reconstructions. Here we present a new adjustment-free reconstruction of solar activity over three millennia and study its different modes.
Methods. We present a new adjustment-free, physical reconstruction of solar activity over the past three millennia, using the latest verified carbon cycle, 14C production, and archeomagnetic field models. This great improvement allowed us to study different modes of solar activity at an unprecedented level of details.
Results. The distribution of solar activity is clearly bi-modal, implying the existence of distinct modes of activity. The main regular activity mode corresponds to moderate activity that varies in a relatively narrow band between sunspot numbers 20 and 67. The existence of a separate Grand minimum mode with reduced solar activity, which cannot be explained by random fluctuations of the regular mode, is confirmed at a high confidence level. The possible existence of a separate Grand maximum mode is also suggested, but the statistics is too low to reach a confident conclusion.
Conclusions. The Sun is shown to operate in distinct modes – a main general mode, a Grand minimum mode corresponding to an inactive Sun, and a possible Grand maximum mode corresponding to an unusually active Sun. These results provide important constraints for both dynamo models of Sun-like stars and investigations of possible solar influence on Earth’s climate.
The recent solar lull(2008-2010) gives much credence to what Professor Lockwood is saying. The
data supports his point of view.
Leif Svalgaard decrease in solar activity since 1980? At most, after the 2000. So who denies the facts? F 10.7 certainly has a fixed minimum?
http://www.climate4you.com/images/SIDC%20DailySunspotNumberSince1900.gif
http://www.swpc.noaa.gov/SolarCycle/Ap.gif
http://www.swpc.noaa.gov/SolarCycle/f10.gif
Salvatore Del Prete says:
August 8, 2014 at 8:32 am
The recent solar lull(2008-2010) gives much credence to what Professor Lockwood is saying. The data supports his point of view.
As I said: “After a Decade of Struggle, Lockwood et al. (2014) are Fast Approaching the Svalgaard et al. Reconstructions of 2003… This is a healthy development and LEA should be congratulated for their achievement, although their model, based on a flawed Sunspot Number series, is not doing too well”
ren says:
August 8, 2014 at 8:54 am
Leif Svalgaard decrease in solar activity since 1980? At most, after the 2000. So who denies the facts?
Ordinarily I wouldn’t bother with you, but let me make an exception for now:
http://www.leif.org/research/Ren-Denial.png
Salvatore Del Prete says:
August 8, 2014 at 8:27 am
As they say to each his own.
Then you could keep it as your own instead of trying to ram it down everybody else’s throat.
Whether you do not see cooling in the Atlantic? The surplus heat in the north quickly disappear.
http://weather.unisys.com/surface/sst_anom.gif
“Whether you do not see cooling in the Atlantic? The surplus heat in the north quickly disappear.
http://weather.unisys.com/surface/sst_anom.gif”
The colormap (key) palette is very suspicious to me. Why is it not a continuous gradient rather than a repeating pattern? The repeating pattern means the information may not be conveyed properly.
Compare a maximum of 1980 of a maximum in 11, 12, 13 cycle.
http://www.solen.info/solar/images/comparison_similar_cycles.png
philjourdan says:
August 8, 2014 at 9:31 am
@Leif – trough.
Good to have online spellcheckers 🙂
@Leif – beats having to get an add on. 😉
rgbatduke says: August 7, 2014 at 2:16 pm
* The final transparency offers evidence that there was significant solar magnetic activity even when there were observationally very few sunspots during e.g. the Maunder minimum.
Leif Svalgaard says: August 8, 2014 at 6:49 am
To my mind, the extraordinary claim is that the solar magnetic field during the Maunder Minimum almost vanished…
It was not solar, but it was the Earth’s magnetic field modulating GCRs . during the Maunder minimum
Hiroko Miyahara (University of Tokyo ) for cosmic rays during Maunder minimum stats that modulation was only present at negative polarity and at a 28 year long periods.
This is more likely to be modulation by the Earth’s magnetic field (see spectrum link in my earlier comment) with two strong components at 5 and 21.3 years, these give cross-modulation at 16 (as shown in the spectrum above) and 26.3 years which is close enough to the Miyahara’s estimate of 28 years.
Unidirectional modulation can come only from a strong DC-type magnetic source with a significant superimposed ripple, which is an accurate description of the Earth’s and not solar magnetic property.
looncraz
http://earth.nullschool.net/#current/ocean/surface/currents/overlay=sea_surface_temp_anomaly/orthographic=-28.63,-4.11,418
http://earth.nullschool.net/#current/wind/isobaric/700hPa/overlay=temp/orthographic=-26.62,27.47,418
vukcevic says:
August 8, 2014 at 9:46 am
It was not solar, but it was the Earth’s magnetic field modulating GCRs . during the Maunder minimum
You are out of your depths, again.
Ed Martin: View the jet stream forecast on August 12.
http://earth.nullschool.net/#2014/08/12/1500Z/wind/isobaric/250hPa/orthographic=-72.98,51.58,836
waa
“I along with countless others subscribe to this point of view.”
Dont trust someone who cant count his supporters, to count the spots.
Leif Svalgaard says:
August 8, 2014 at 10:31 am
vukcevic says:
> August 8, 2014 at 9:46 am </a
It was not solar, but it was the Earth’s magnetic field modulating GCRs . during the Maunder minimum
…………
You are out of your depths, again
That doesn’t sound like very convincing hypothesis rebuttal.
On the other hand, you might be a bit short of a convincing contra-argument, so what else one is to do?
Well, one can always result to rubbishing the messenger, as it is widely practiced by warmites.
vukcevic says:
August 8, 2014 at 11:14 am
That doesn’t sound like very convincing hypothesis rebuttal.
There are things worthy of rebuttal and there is rubbish.
You could LOOK at the evidence in his talk, for example, before making an assertion like this. The reason that he — and others — think that there was a substantial magnetic field during the Maunder minimum is (if I understand it correctly) because there were solar eclipses that occurred late in the sunspot-free period and phenomena were observed in the corona that are only associated with reasonably strong magnetic fields. This obviously has nothing to do with geomagnetic effects, and suggests (not proves, which is why he is careful not to assert proof) that at least late in the Maunder minimum, the sun had a substantial magnetic field.
IIRC there is secondary corroboratory evidence for this in radioisotope data, but I’m not certain of that as this isn’t my field and I’m operating on memory of other postings and discussions.
The point is that the Maunder minimum may or may not be “the cause” of the LIA. The timing isn’t exactly right. There is certainly nothing like a smoking gun of linear correlation. However, there is some correspondence. The big question is whether or not the lack (mostly) of apparent sunspots was, in fact, accompanied by a minimum in solar magnetic field and increase in atmospheric neutron level that might support e.g. Svenmark. But neutron/radioisotope data tends to be blurred out historically because of transport processes and confounding causes.
Personally, I’m inclined to think that the LIA had multiple “causes”. Perhaps solar variation was one of them, but there were probably at least some others to explain the imprecise alignment of the timing, and in a multivariate model, trying to project any evidence back into a broad region of potential covariance is an open invitation to confirmation bias. The best one can really say is perhaps it isn’t INconsistent, not that it is proven, and then only if there are multiple causes.
rgb
Personally, I’m inclined to think that the LIA had multiple “causes”. Perhaps solar variation was one of them.
Yes, and when one looks at the data one will see the global temperature trend in down with out exception when prolonged minimum solar conditions are present, and vice versa.
Professor Lockwood is right on in his assessment of how the solar magnetic field has changed from the Maunder Minimum to the Modern Maximum. It was a drastic change and now post 2005 the solar parameters are heading down once again.
The data speaks for itself and supports solar variability to a much grater degree then what some posters would like you to believe.
They are in denial of the data which is common place when it comes to the climate and why it changes.
I am growing more confident as studies such as Lockwood’s keep coming out and show through data that solar variability is much greater then what mainstream tries to convey and that it indeed impacts the climate through primary and secondary means.
This will be proven more as this decade proceeds and the current prolonged solar minimum continues and becomes deeper.
The AP index is a great indicator of how the state of the sun has gone from an active state to an inactive state post 2005.
http://www.solen.info/solar/images/comparison_recent_cycles.png
Look at how each solar cycle is declining from the modern maximum to the now solar minimum.
Solar Cycle 25 will likely be weaker yet.
The data shows that the sun is quite variable.
The LIA was a period of tremendous volcanic activity, some of which were catastrophic eruptions in the equatorial band. This is known because signatures are seen in both polar ice cores, indicative of ejecta into the stratosphere. My speculation is that while the stratospheric sulfur gas and ash do not last beyond a couple of years, the aerosol veil and triggered El Nino conditions are enough to substantially shut down solar recharge of equatorial oceanic waters such that when these waters ride the currents beyond the equatorial band, this much cooler water brings chilling weather on a global basis for many years, if not decades.
It is of interest to the science community regarding volcanic eruptions and the overturning circulation. Was that process stalled during the LIA? I think the overturning continued but the oceans didn’t have anything in their tanks that brings warmth to places beyond the equator. And it took a tremendous amount of time to bring that tank back to full. This is how I think catastrophic equatorial eruptions can affect global temperatures for years and decades, even after the veil has cleared. The eruption didn’t stall the overturning circulation, it stalled the equatorial discharge/recharge process by just triggering discharge. That disrupted process would have the ability to eventually negatively affect the entire globe.
Since the scientists have high confidence in Solar grand minimum data, why not look at the correlation to temperature and CO2 in ice columns relative to solar grand minimums?
It should show a decrease in temperature if magnetic effects and high energy particles significantly effect climate.
If any of these are pre-industrial ages then those that are within the industrial age to present will be different than the ones prior.
For CO2 the the cause in effect will be reversed for the % of the most recent being caused by human activity. CO2 would go down with a drop in temperature in pre-industrialized times vs during and after the industrial age. A differential between these when normalised over the data sets could show up supporting or to the detriment to Global Warming and Global Extremes.
Dr. Brown,
Thanks for the attention, I am always willing to listen to a good advise, in following it may not be as responsive.
a) Let’s get the LIA out of the way, it is coincidental with the back end of the Maunder minimum, but not necessarily caused by it.
I’ll rather put my money on the Arctic submarine volcanoes, not on the account of the heat contribution or lack there of (which may not be negligible), but on the account of interference with the North Icelandic Jet, deep cold water current. It has been noted that this current is very ‘temperamental’. The Arctic’s deep cold water overflow is a precondition for the warm Atlantic surface inflow (which sinks below surface further north). No cold overflow, no warm inflow, result icing up of the Arctic ocean and onset of the LIA.
Ok, you disagree, but just as well you could take a look at this:
b) on the Earth magnetic field spectrum see above my
comment 1
and comment 2 .
I agree with Dr. S that solar Hale cycle magnetic field does not penetrate to the Earth’s core, but according to data from distinguished scientist and used by the JPL-NASA, the Earth’s magnetic field contains 2 x sunspot period and the core 65 year periodicity with 4th harmonic (i.e. ~16 year component) in the core’s angular momentum.
65 year (the AMO like) periodicity emanating from the Earth core is just about OK, but Hale type magnetic periodicity (by n orders of magnitude stronger than the heliospheric magnetic field at the earth’s orbit) is a scientific ‘madness’.
The same scientists who produced the date, have calculated the change in the core angular momentum and converted it to the an equivalent contribution to the LOD change.
Using high-pass filter I eliminated low end of the spectrum from their data and what I have left is shown
here
Despite the fact that I read and consider your comments as possibly the best thought out (although many parts, relating to statistics more often than not, are well beyond my grasp), not for one moment I expect of you to give even a second thought to what I write.
The idea that both solar and the Earth magnetic field display the exactly same magnetic periodicity over period the data is available for both it is the stuff pursued by ‘cranks and astrologers’, it is not something that a sane (solar) scientist would contemplate.
And finally, if I may, for understanding general trends in natural variability pursue the Arctic atmospheric pressure and the N. Atlantic SST relationship.
To understand the ENSO (I am told that it may be long term neutral) forget about Darwin and Tahiti, go to Port Moresby.
If you got as this far, I’ll say, thanks again.
Sorry I missed a link:
……….you could take a look at this :
Pamela Gray says:
August 8, 2014 at 1:20 pm
The LIA was not clearly more volcanic than the Modern Warm Period so far, despite Mann, et al’s attempt to paint it as such. Number of VEI 6 or 7 eruptions:
Medieval Warm Period, AD c. 800-1400: six in 600 years (1/100 years on average, although one was a VEI 7, or two, rating the unrated 750 ybp event a 7, & some may be missing)
LIA, AD c. 1400-1850: nine in 450 years (1/50 years, although Tambora was a VEI 7)
Modern Warm Period, AD c. 1850-2014: four in 164 years (1/41 years, but no VEI 7 yet)
An earlier onset for the Medieval WP nets more VEI 6s.
http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=9&ved=0CGMQFjAI&url=http%3A%2F%2Fwww.tetontectonics.org%2FClimate%2FWard2009TableS1.pdf&ei=cTzlU8iELsb5oATXsIHwDA&usg=AFQjCNHtXofou-_3osa_BYFDvL6k6uX2jw&sig2=HD5PFo7b2Qzl0RQT0L95wA&bvm=bv.72676100,d.cGU
But in any case, evidence suggests that the longer term effect of large volcanic eruptions is winter warming over most regions, not the bitter cooling of the LIA.
GEOPHYSICAL RESEARCH LETTERS,
VOL. 12, NUMBER 24, PAGES 2405-2408, DECEMBER 24, 1992
WINTER WARMING FROM LARGE VOLCANIC ERUPTIONS
Alan Robock and Jianping Mao
Department of Meteorology, University of Maryland, College Park
Abstract
“An examination of the Northern Hemisphere winter surface temperature patterns after the 12
largest volcanic eruptions from 1883-1992 shows warming over Eurasia and North America and cooling over the Middle East which are significant at the 95% level. This pattern is found in the first winter after tropical eruptions in, the first or second winter after midlatitude eruptions, and
in the second winter after high latitude eruptions. The effects are independent of the hemisphere of the volcanoes.
“An enhanced zonal wind driven by heating of the tropical stratosphere by the volcanic aerosols is responsible for the regions of warming, while the cooling is caused by blocking of incoming sunlight.”
There is no evidence supporting your contention that an increase in subaerial volcanism could produce the LIA. There is however overwhelming evidence that the LIA was a natural fluctuation in cyclic climate change during the Holocene, as also observed on comparable time scales in prior interglacials and for that matter during glacials. Single volcanic eruptions affect weather for a few years, not climate for hundreds of years. Long periods of nearly continuous submarine volcanism can however affect climate, as happened during parts of the Jurassic and Cretaceous Periods when seafloor spreading was more active as Pangaea broke up. It’s also possible that seismic activity could play a role in the weather events of the ENSO.