From the American Geophysical Union weekly highlights:
Key Points
- Minimum 23-24 showed recurrence intervals of 9.0 and 6.7-d
- Historical geomagnetic activity data show that minimum 23-24 was unusual
- The heliosphere during minimum 23-24 had unusual sectorial structure
Since the mid-1800s, scientists have been systematically measuring changes in the Earth’s magnetic field and the occurrence of geomagnetic activity. Such long- term investigation has uncovered a number of cyclical changes, including a signal associated with 27-day solar rotation. This is most clearly seen during the declining phase and minimum of each 11-year solar cycle, when the Sun’s magnetic dipole is sometimes tilted with respect to the Sun’s rotational axis. With the Sun’s rotation and the emission of solar wind along field lines from either end of the solar magnetic dipole, an outward propagating spiral-like pattern is formed in the solar wind and the interplanetary magnetic field that can drive 27-day, and occasionally 13.5-day, recurrent geomagnetic activity. Recurrent geomagnetic activity can also be driven by isolated and semipersistent coronal holes, from which concentrated streams of solar wind can be emitted.
During the most recent solar minimum, which took place from 2006 to 2010, however, several researcher groups noticed 6.7-day and 9-day recurrent changes in geomagnetic activity, and similar patterns in the interplanetary magnetic field, and the solar wind.
Using modern data covering the previous two solar minima, these higher-frequency occurrences were judged to be unusual. Love et al. analyzed historical geomagnetic activity records from 1868 to 2011 and find that the 6.7-day and 9-day recurrent changes were actually unique in the past 140 years. They suggest that the higher-frequency changes in geomagnetic activity are due to an unusual transient asymmetry in the solar dynamo, the turbulent, rotating plasma deep within the sun which generates the magnetic field.
Source: Geophysical Research Letters, doi:10.1029/2011GL050702, 2012
http://dx.doi.org/10.1029/2011GL050702
Title: Geomagnetic detection of the sectorial solar magnetic field and the historical peculiarity of minimum 23-24
Authors: Jeffrey J. Love and E. Joshua Rigler: Geomagnetism Program, U.S. Geological Survey, Denver, Colorado, USA;
Sarah E. Gibson: High Altitude Observatory, NCAR, Boulder, Colorado, USA.
Abstract:
Analysis is made of the geomagnetic-activity aa index covering solar cycle 11 to the beginning of 24, 1868–2011. Autocorrelation shows 27.0-d recurrent geomagnetic activity that is well-known to be prominent during solar-cycle minima; some minima also exhibit a smaller amount of 13.5-d recurrence. Previous work has shown that the recent solar minimum 23–24 exhibited 9.0 and 6.7-d recurrence in geomagnetic and heliospheric data, but those recurrence intervals were not prominently present during the preceding minima 21–22 and 22–23. Using annual-averages and solar-cycle averages of autocorrelations of the historical aa data, we put these observations into a long-term perspective: none of the 12 minima preceding 23–24 exhibited prominent 9.0 and 6.7-d geomagnetic activity recurrence. We show that the detection of these recurrence intervals can be traced to an unusual combination of sectorial spherical-harmonic structure in the solar magnetic field and anomalously low sunspot number. We speculate that 9.0 and 6.7-d recurrence is related to transient large-scale, low-latitude organization of the solar dynamo, such as seen in some numerical simulations.
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Sarc/on
Without the ethics guru Glick at the helm leading the way on Ethics in Science; his departure provides a window to jam through all kinds of stuff which may not have his stamp of approval :-}
I think it must be the re-radiation of the carbondioxide being returned from earth to the sun.
http://www.letterdash.com/HenryP/the-greenhouse-effect-and-the-principle-of-re-radiation-11-Aug-2011
@cal – but did the sun have a fever in the 19th and 20th century and are the so called shivers in actual fact normality?
In my earlier post regarding chaos theory I should have gone on to mention ‘period doubling’. Briefly, whenever a system makes a transition from stable oscillation to chaotic behavior, (and any system at all that shows period three can do this), the process commences with period doubling (http://en.wikipedia.org/wiki/Period-doubling_bifurcation). Cycles of 2, 4, 8 appear with increasing rapidity, and then chaos ensues.
The appearance of a cycle of period 4 suggests this could be happening. Let’s hope not. I have no idea what happens if this solar cycle becomes chaotic, but it might be better not to know !
It seems to me that this is saying we should have seen a pretty extensive cooling of the planet in the past few years. Since temperatures have been flat, there are really only two take aways. Either, (1) solar variations aren’t as important as I would have thought, or (2) something besides the sun is causing the Earth to absorb a higer percentage of the sun’s energy.
Or, I suppose, it could be a little of both.
ref. “take home” / takeaway, …
Are there studies and/or evidence suggesting a relationship between geomagnetic parameters (esp. resulting from solar activity) and geoclimate?
Certainly the evidence is strong for correlation between a dearth of sunspots and a cooler geoclimate. And a longer, flatter solar cycle would appear to correspond to the same.
My question is thus: is this merely an observation of “here’s something different”, so “stay posted”, or are there any rough order of magnitude conclusions to be drawn?
Kurt in Switzerland
Henry says:
http://wattsupwiththat.com/2012/03/19/geomagnetic-data-reveal-unusual-nature-of-recent-solar-minimum/#comment-928364
Theoretically, it is true that some back radiation from the CO2 would be sent back straight to the sun. But I was only joking as to it having any effect, of course.
Henry@ur momisugly Rick Powell
It seems the increasing greenery on earth is trapping some heat, but that is only a minor factor. I suspect ozone could be one of the (main) culprits of the warming. In its turn, the ozone hole and the thickness of the ozone layer depend on the sun
UV + O2 + O => O3
http://www.letterdash.com/HenryP/henrys-pool-table-on-global-warming
Radio experiments started in the 1860s. Hertz beam RF in to space in 1886, coincident? The sun can only be saved if we stop all RF transmitions immediately.
I have two requests:
1) Are there data-sets or graphs that show the “accurate” diameter of the Sun over, say, 100 [or better, 200] years? Surely that is not a constant?!?! This is difficult to determine on a gaseous body, but I’m sure some group has measured it. I can’t find any record.
2) Are there data-sets or graphs that show the heights of the regions of Earth’s atmosphere? Specifically, at the equator, mid-latitude, poles, etc., for each month for 100 or better 200 years? Again, this would be difficult to determine, but consistent measurement techniques would give good estimates.
More data to determine how the Sun effects our atmosphere. Relationship of magnetic field strength to Sun’s diameter.
Thanks
Honestly now so what’s the big deal. There isn’t a thing anyone can do about it so why get excited. The sun is so big that the best anyone can do is to “roll with the punch i.e. adapt.
Ahem! As the new head of the InterGalactic Panel of Concerned Cronies to save the universe I’ll be needing some suitable transport to get the message out there
http://www.bigredkev.com/2010/05/knight-xv-worlds-largest-suv.html
and as such will be taking applications from suitably like minded concerned cronies forthwith (eminently recyclable envelopes and brown paper bags are available for a small fee from my personal secretary)
Remember it’s only for Galactic Gaia we will fight the good fight with your Galactic vacuum taxes folks!
Err..in my haste to get saving Galactically I almost forgot to mention- Strictly no email applications.
I’m not sure what you’re asking for here. Since the Forbush-cloud relationship isn’t particularly recent, I assume there is something about the recent data that is interesting. ??? Sorry for being thick but I am curious about what you meant.
Zdrastvuy Comrade Bob
Last week there was the deepest Forbush decline in years (~15%) , here is the tail end of it:
http://neutronm.bartol.udel.edu/~pyle/TheThPlot.gif
Proletariat still asleep ?
Bob, sorry wrong link. Here is one which shows all of this month’s decline:
http://neutronm.bartol.udel.edu/~pyle/TheThPlot2.gif
Rick Powell says:
March 19, 2012 at 7:02 am
It seems to me that this is saying we should have seen a pretty extensive cooling of the planet in the past few years. Since temperatures have been flat, there are really only two take aways. Either, (1) solar variations aren’t as important as I would have thought, or (2) something besides the sun is causing the Earth to absorb a higer percentage of the sun’s energy.
Or, I suppose, it could be a little of both.
“we should have seen a pretty extensive cooling of the planet in the past few years”
Or as many researchers have been pointing out that there is a considerable lag as the oceans take a long time to cool. The normal analogy is when you boil a pan of water turning off the heat doesn’t cause a rapid drop in temperature – it just stops rising and starts to slowly cool. As you point out that appears to be what is happening atmospheric temperatures have been flat. But look at the ENSO SST page here and the preponderance of dark blue in the oceans of the Unisys Anomaly plot.
Let’s just hope that the sun has turned down only to simmer and not too low.
Too many have taken this post to post jokes, which is understandable, however it is a very serious matter if these changes are having a direct effect on GMF.
@vukcevic says:
March 19, 2012 at 9:16 am
Proletariat still asleep ?
Dear Vuk: Human beings have a self defense psychological “buffer” which impedes them to see reality when it entails something scaring. Self deceiving when in excess impedes even well respected members of the academia to reject the obvious.
@Richard Dupuis Powell says:
>>It seems to me that this is saying we should have seen a pretty extensive cooling of the planet in the past few years. Since temperatures have been flat, there are really only two take aways. Either, (1) solar variations aren’t as important as I would have thought, or (2) something besides the sun is causing the Earth to absorb a higer percentage of the sun’s energy.<<
These changes don't correlate directly. Regardless of whether the temperatures are increasing or decreasing, it's like money in the bank gathering interest. The effects of reduced or increased solar electromagnetic activity will be cumulative over time, I believe. That's why you see a lag time of 800 years between increased temperatures and accumulation of CO2 in the atmosphere, and why the CO2 continues to increase even as temperatures begin to cool. The oceans are doubtless a major factor.
Should see a strong spike in the SWPC chart for geomagnetic activity for March. After all the misses and glancing blows, got hit pretty good this month with flares and high solar winds.
http://www.solen.info/solar/images/solar.gif
http://www.solen.info/solar/images/swind1.gif
That is an X5 flare causing that decline, I believe. We’ve had some rather spectacular flares from one spot group.
vukcevic says:
March 19, 2012 at 5:22 am
Just added spectral response for the Ap max as measured at Tromso.
http://www.vukcevic.talktalk.net/Tromso.htm
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Thanks for the graph and thanks for adding a legend so we can figure out what is what. Your graphs add a lot to the discussion.
Rick Powell says:
March 19, 2012 at 7:02 am
It seems to me that this is saying we should have seen a pretty extensive cooling of the planet in the past few years. Since temperatures have been flat, there are really only two take aways. Either, (1) solar variations aren’t as important as I would have thought, or (2) something besides the sun is causing the Earth to absorb a higer percentage of the sun’s energy.
Or, I suppose, it could be a little of both.
____________________________________
Do not forget the oceans store heat and act sort of like a capacitor, so changes to the sun are not going to be seen reflected in the temperature immediately. I would hazard a guess that the changes will be in ENSO.
http://lasp.colorado.edu/sorce/images/instruments/sim/fig01.gif
Also we HAVE seen changes. The Jet Streams have become more “loopy” http://chiefio.wordpress.com/2011/03/06/of-turbulence-hadley-ferrel-cells-and-loopy-jet-streams/
The whole idea that there is ONE variable that is responsible for the climate/temperature should be a non-starter.
Hmm
As it happens I have been mucking with extracting the cycles in the sunspot numbers going back to 1750. It has been quite a fascinating exercise, using the Periodicity Transform, mentioned by Willis Eschenbach previously.
The correlation with the the orbits of Jupiter, Saturn and Neptune are striking (or was that Uranus – I always forget which is closer).
What effect does the gravitational effect of these planets have on the sun’s “dynamo”?
Presumably the effect will be observable in other other ways too?
(As an aside – I tried forecasting the monthly SSN from the cycles I extracted. The result is a low cycle this time around followed by negative number after 2020???? That’s not possible. A bit of thought shows that I should really take account of a sign change from one cycle to the next. The change is lost in the method of recording sunspot numbers. Resolving that problem is tommorrow’s work !-)
Vincent says:
March 19, 2012 at 3:01 pm
………….
Something like this: http://www.vukcevic.talktalk.net/NFC7a.htm