Dr. Roger Pielke Sr. writes about a new paper from Nicola Scafetta.:
A new paper has just appeared
Nicola Scafetta 2011: A shared frequency set between the historical mid-latitude aurora records and the global surface temperature. Journal of Atmospheric and Solar-Terrestrial Physics In Press doi:10.1016/j.jastp.2011.10.013
This paper is certainly going to enlarge the debate on the role of natural climate variability and long term change.
The abstract reads [highlight added]
Herein we show that the historical records of mid-latitude auroras from 1700 to 1966 present oscillations with periods of about 9, 10–11, 20–21, 30 and 60 years. The same frequencies are found in proxy and instrumental global surface temperature records since 1650 and 1850, respectively, and in several planetary and solar records. We argue that the aurora records reveal a physical link between climate change and astronomical oscillations. Likely in addition to a Soli-Lunar tidal effect, there exists a planetary modulation of the heliosphere, of the cosmic ray flux reaching the Earth and/or of the electric properties of the ionosphere. The latter, in turn, has the potentiality of modulating the global cloud cover that ultimately drives the climate oscillations through albedo oscillations. In particular, a quasi-60-year large cycle is quite evident since 1650 in all climate and astronomical records herein studied, which also include a historical record of meteorite fall in China from 619 to 1943. These findings support the thesis that climate oscillations have an astronomical origin. We show that a harmonic constituent model based on the major astronomical frequencies revealed in the aurora records and deduced from the natural gravitational oscillations of the solar system is able to forecast with a reasonable accuracy the decadal and multidecadal temperature oscillations from 1950 to 2010 using the temperature data before 1950, and vice versa. The existence of a natural 60-year cyclical modulation of the global surface temperature induced by astronomical mechanisms, by alone, would imply that at least 60–70% of the warming observed since 1970 has been naturally induced. Moreover, the climate may stay approximately stable during the next decades because the 60-year cycle has entered in its cooling phase.
The highlights listed in the announcement of the paper read
► The paper highlights that global climate and aurora records present a common set of frequencies. ► These frequencies can be used to reconstruct climate oscillations within the time scale of 9–100 years. ► An empirical model based on these cycles can reconstruct and forecast climate oscillations. ► Cyclical astronomical physical phenomena regulate climate change through the electrification of the upper atmosphere. ► Climate cycles have an astronomical origin and are regulated by cloud cover oscillations.
========================================================
Dr. Scafetta writes in and attaches the full paper in email to me (Anthony) this week saying:
I can forecast climate with a good proximity. See figure 11. In this new paper the physical link between astronomical oscillations and climate is further confirmed.
What the paper does is to show that the mid-latitude aurora records present the same oscillations of the climate system and of well-identified astronomical cycles. Thus, the origin of the climatic oscillations is astronomical what ever the mechanisms might be.
In the paper I argue that the record of this kind of aurora can be considered a proxy for the electric properties of the atmosphere which then influence the cloud cover and the albedo and, consequently, causes similar cycles in the surface temperature.
Note that aurora may form at middle latitude or if the magnetosphere is weak, so it is not able to efficiently deviate the solar wind, or if the solar explosions (solar flare etc) are particularly energetic, so they break in by force.
During the solar cycle maxima the magnetosphere gets stronger so the aurora should be pushed toward the poles. However, during the solar maxima a lot of solar flares and highly energetic solar explosions occurs. As a consequence you see an increased number of mid-latitude auroras despite the fact that the magnetosphere is stronger and should push them toward the poles.
On the contrary, when the magnetosphere gets weaker on a multidecadal scale, the mid-latitude aurora forms more likely, and you may see some mid-latitude auroras even during the solar minima as Figure 2 shows.
In the paper I argue that what changes the climate is not the auroras per se but the strength of the magnetosphere that regulates the cosmic ray incoming flux which regulate the clouds.
The strength of the magnetosphere is regulated by the sun (whose activity changes in synchrony with the planets), but perhaps the strength of the Earth’s magnetosphere is also regulated directly by the gravitational/magnetic forces of Jupiter and Saturn and the other planets whose gravitational/magnetic tides may stretch or compress the Earth’s magnetosphere in some way making it easier or more difficult for the Earth’s magnetosphere to deviate the cosmic ray.
So, when Jupiter and Saturn get closer to the Sun, they may do the following things: 1) may make the sun more active; 2) the more active sun makes the magnetosphere stronger; 3) Jupiter and Saturn contribute with their magnetic fiend to make stronger the magnetic field of the inner part of the solar system; 4) the Earth’ magnetosphere is made stronger and larger by both the increased solar activity and the gravitational and magnetic stretching of it caused by the Jupiter and Saturn. Consequently less cosmic ray arrive on the Earth and less cloud form and there is an heating of the climate.
However, explaining in details the above mechanisms is not the topic of the paper which is limited to prove that such kind of mechanisms exist because revealed by the auroras’s behavior.
The good news is that even if we do not know the physical nature of these mechanisms, climate may be in part forecast in the same way as the tides are currently forecast by using geometrical astronomical considerations as I show in Figure 11.
The above point is very important. When trying to predict the tides people were arguing that there was the need to solve the Newtonian Equation of the tides and the other physical equations of fluid-dynamics etc. Of course, nobody was able to do that because of the enormous numerical and theoretical difficulty. Today nobody dreams to use GCMs to predict accurately the tides. To overcome the issue Lord Kelvin argued that it is useless to use the Newtonian mechanics or whatever other physical law to solve the problem. What was important was only to know that a link in some way existed, even if not understood in details. On the basis of this, Lord Kelvin proposed an harmonic constituent model for tidal prediction based on astronomical cycles. And Kelvin method is currently the only method that works for predicting the tides. Look here:
http://en.wikipedia.org/wiki/Tide-predicting_machine
Figure 11 is important because it shows for the first time that climate can be forecast based on astronomical harmonics with a good accuracy. I use a methodology similar to Kelvin’s one and calibrate the model from 1850 to 1950 and I show that the model predicts the climate oscillations from 1950 to 2010, and I show also that the vice-versa is possible.
Of course the proposed harmonic model may be greatly improved with additional harmonics. In comparison the ocean tides are predicted with 35-40 harmonics.
But this does not change the results of the paper that is: 1) a clearer evidence that a physical link between the oscillations of the solar system and the climate exists, as revealed by the auroras’ behavior; 2) this finding justifies the harmonic modeling and forecast of the climate based on astronomical cycles associated to the Sun, the Moon and the Planets.
So, it is also important to understand Kelvin’s argument to fully understand my paper.
…
This work is the natural continuation of my previous work on the topic.
Nicola Scafetta. Empirical evidence for a celestial origin of the climate
oscillations and its implications. Journal of Atmospheric and Solar-Terrestrial Physics Volume 72, Issue 13, August 2010, Pages 951-970
http://www.sciencedirect.com/science/article/pii/S1364682610001495
Abstract
We investigate whether or not the decadal and multi-decadal climate
oscillations have an astronomical origin. Several global surface temperature
records since 1850 and records deduced from the orbits of the planets
present very similar power spectra. Eleven frequencies with period between 5
and 100 years closely correspond in the two records. Among them, large
climate oscillations with peak-to-trough amplitude of about 0.1 and 0.25°C,
and periods of about 20 and 60 years, respectively, are synchronized to the
orbital periods of Jupiter and Saturn. Schwabe and Hale solar cycles are
also visible in the temperature records. A 9.1-year cycle is synchronized to
the Moon’s orbital cycles. A phenomenological model based on these
astronomical cycles can be used to well reconstruct the temperature
oscillations since 1850 and to make partial forecasts for the 21st century.
It is found that at least 60% of the global warming observed since 1970 has
been induced by the combined effect of the above natural climate
oscillations. The partial forecast indicates that climate may stabilize or
cool until 2030–2040. Possible physical mechanisms are qualitatively
discussed with an emphasis on the phenomenon of collective synchronization
of coupled oscillators.
=======================================================
The claims here are pretty bold, and I’ll be frank and say I can’t tell the difference between this and some of the cycl0-mania calculation papers that have been sent to me over the last few years. OTOH, Basil Copeland and I looked at some of the effects of luni-solar on global temperature previously here at WUWT.
While the hindcast seems impressive, a real test would be a series of repeated and proven short-term future forecasts. Time will tell.
Agile Aspect says:
November 16, 2011 at 1:05 am
The peak values are located at roughly 1720, 1780, and 1850 years.
But then the relation breaks down, because at the next 60 year mark, in 1910, solar activity [and hence auroral activity] was at a very deep low. This is the usual fate of spurious relationships.
Mid latitude aurora are part of the magnetic reconnection process.
Makes you wonder if Jupiter or Saturn, both have polar Aurora and vortex, ever experience mid latitude aurora?
Now I have to wonder if the heliosphere experiences a quasi aurora of sorts.
Here’s why;
M. A. Dayeh et al. 2011 ApJ 734 29 doi:10.1088/0004-637X/734/1/29
SPECTRAL PROPERTIES OF REGIONS AND STRUCTURES IN THE INTERSTELLAR BOUNDARY EXPLORER (IBEX) SKY MAPS
M. A. Dayeh1, D. J. McComas1,2, G. Livadiotis1, R. W. Ebert1, H. O. Funsten3, P. Janzen4, D. B. Reisenfeld4 and N. A. Schwadron1,5
We study the spectral properties of different regions and structures in the energetic neutral atom (ENA) maps at energies from ~0.5 keV to ~6 keV from the Interstellar Boundary Explorer (IBEX) mission. We find that (1) an ankle-shaped break (spectrum hardens) between ~1 keV and ~2 keV characterizes the polar spectra and the right flank, while a knee-shaped break (spectrum softens) describes the ribbon, nose, and the front region spectra; (2) the spectral indices across full latitudinal range (tail and poles) comprise a dependence reflecting a knee break at mid latitudes and an ankle break at high latitudes. This latitudinal evolution has inflection points at ~40°S and ~36°N, and is strongly correlated with the solar wind speed structure obtained by the Ulysses/SWOOPS instrument during its fast latitude scan in 2007. Our study confirms that the ecliptic latitude predominantly orders the spectral signatures of ENA distributions. This ordering may reflect the average solar wind properties that vary characteristically with latitude around solar minimum. We report on the spectral analyses of six regions and two structures in the IBEX maps. We also discuss the spectral asymmetries between the north and the south polar regions, their correlation with solar wind measurements, and the implications of these observations. Thus, we show detailed connections between the IBEX energy spectra and latitudinal properties of solar wind.
Talk about vivid imaginations and wild ideas about the reconnection process, (not even I would have thunk this one). D McComas was on this team.
Local Interstellar Cloud -Local Bubble boundary as a possible source for the IBEX Ribbon
Grzedzielski, Stan; Bzowski, Maciej; Czechowski, Andrzej; Funsten, Herbert; McComas, David; Schwadron, Nathan A.
38th COSPAR Scientific Assembly. Held 18-15 July 2010, in Bremen, Germany, p.7
The brightest and most surprising feature in the first all-sky map of Energetic Neutral Atoms (ENA) emissions (0.2 -6 keV) completed by the Interstellar Boundary Explorer (IBEX) is an almost circular ribbon of a ˜ 140° opening angle, centered at (l, b) = (33° , 55° ) galactic coordinates and covering the part of the celestial sphere with the lowest column densities of the Local Interstellar Cloud (LIC). We propose a novel interpretation of the IBEX results based on the idea that the ribbon ENAs are produced by charge-exchange between the neutral H atoms at the nearby edge of the LIC and the hot protons of the Local Bubble (LB) rather than due to interaction of the heliosphere itself with the local interstellar medium. These ENAs from the LIC-LB interaction should be able to reach the Sun’s vicinity because of the thinness of the intervening LIC material. We show that a slightly curved interface layer of contact between the LIC H atoms (nH = 0.2 cm-3 , T = 6000 – 7000 K) and the LB protons (np = 0.005 cm-3 , T ˜ 106 K) might explain both the almost-circular shape of the ribbon and its observed ENA intensities, provided that the edge is < {500, 2000}AU distant, the LIC proton density (correspondingly) < {0.04, 0.01} cm-3 , and the LB contains ˜ 1% of non-thermal protons in the IBEX energy range. Secondary ENAs, which originate from a hierarchy of multiple charge exchange interactions between the energetic H atoms reentering the LIC from the LB and the LIC plasma should form an omni-directional globally distributed ENA flux which may be responsible for at least part of the high-energy signal observed by IBEX. The new ideas presented here about the LIC-LB sources of ENAs are totally independent of the existing heliospheric models. If these ideas are correct, IBEX may provide a way to determine the distance to the LIC edge and a means to determine the plasma conditions in the LB.
I wisht the planetary theorists would take alook at the bigger picture.
Leif Svalgaard says:
November 15, 2011 at 11:57 pm
Since today we know the physics and we have excellent data and therefore know that the aurorae follow very well the sunspot record, you can conclude that if an auroral record does not agree with this, then that record is faulty and unreliable. This is the point you and Nicola are missing.
There are 20,000 records from several hundred stations behind just one of the graphs listed. These are not derived from news paper clippings but from a much more reliable source according to Silverman.
Data for New England were taken from a compilation by
S. M. Silverman based on several sources (for a description
of observational systems from the end of the eighteenth cen-
tury to 1870, see Fleming [1990]). The primary source used
here was the meteorological registers kept by voluntary ob-
servers in the network established by the Smithsonian Insti-
tution and continued, primarily, by the Army Signal Service
and the Weather Bureau. Observations were also published
in the Monthly Weather Review and in the series, Climato-
logical Data of the United States. Some additional data for
individual locations were also used, as, for example, the
observations of Bentley in Jericho, Vermont, from 1881 to
1931 [Silverman and Blanchard, 1983]. Some data were also
taken from the auroral catalogs published by Lovering [ 1866-
1871] and Fritz [1873]. The New England data base com-
prised about 20,000 records, from 1741 to 1948. Some scat-
tered records prior to 1741 exist but are not utilized here.
Altogether several hundred locations are involved. Their geo-
graphic coordinates range from about 41 ø to 45 ø , and the
corresponding corrected geomagnetic coordinates from about
53 ø to 57 ø .
An aurora at mid latitude should stand out like a sore thumb, but I am open to your ideas why the record is not reliable?
Carla says:
November 16, 2011 at 5:31 am
Our study confirms that the ecliptic latitude predominantly orders the spectral signatures of ENA distributions. This ordering may reflect the average solar wind properties that vary characteristically with latitude around solar minimum.
This is as expected as the mass flux is largest near the equatorial plane [makes no difference if you use ecliptic latitude instead]. So a prediction will be that the ribbon will disappear in a couple of years when we are just past maximum and the solar wind is much more uniform in latitude.
Now, all of this has no impact on the sun, solar cycle, earth, climate, etc.
Geoff Sharp says:
November 16, 2011 at 5:51 am
There are 20,000 records from several hundred stations behind just one of the graphs listed. These are not derived from news paper clippings but from a much more reliable source according to Silverman.
That is so for the records after about the 1880s, but not before.
An aurora at mid latitude should stand out like a sore thumb, but I am open to your ideas why the record is not reliable?
It would, but there is no guarantee that it will be recorded correctly. The major argument about the unreliability of the auroral record is that aurorae have a magnetic signature which is objective and observable 24/7. We have good magnetic records back to the 1830s and those clearly show great discrepancies with the auroral records, testifying to the unreliability of the latter. Apart from the disagreements between the individual auroral records. The magnetic record on the other hand never has any disagreement between stations as magnetic storms are worldwide. As we learned about the connection between aurorae and magnetism [discovered in 1740s] and figured out the physics after the IGY in the 1950s and 60s, we stopped keeping track of the aurorae as it was realized that such a record could not be made reliable, and was now not needed any longer as the it was just a poor proxy of the magnetic record. In spite of your statement of being open to this, I don’t think you really are, as you have already been shown many examples and explanations of why the record is no good.
Leif Svalgaard says:
November 16, 2011 at 8:43 am
An aurora at mid latitude should stand out like a sore thumb, but I am open to your ideas why the record is not reliable?
As Silverman points out, even an imperfect and flawed record can be useful for times where we have no other data, as we often will be able to correct or compensate for the flaws [based on our modern understanding of the physics behind the record]. E.g. as Krivsky and Pejml did with their ‘civilization factor’. But to use the raw record will often get you in trouble, like Scafetta got, when he was speculating on why there should be more aurorae at solar minimum [there aren’t].
Leif Svalgaard says:
November 16, 2011 at 8:43 am
It would, but there is no guarantee that it will be recorded correctly. The major argument about the unreliability of the auroral record is that aurorae have a magnetic signature which is objective and observable 24/7. We have good magnetic records back to the 1830s and those clearly show great discrepancies with the auroral records, testifying to the unreliability of the latter. Apart from the disagreements between the individual auroral records.
Because one record doesn’t agree with another is no reason to call one unreliable. The aurora record as seen can occur when Kp values are low, there is probably a valid reason which Nicola has touched on that may have other downstream effects on climate etc. If one portion of the planet experiences an aurora while the planet average Kp value is low may just mean that portion of the planet is experiencing a localized phenomenon. What if that area of the planet was a large area in the North Pacific that stayed cloudless for an extended period of time? Perhaps the beginning of an understanding of why the PDO occurs? Agreed the evidence is flimsy right now, but certainly worth investigating.
This may come as a bit of disappointment to Dr. Scafetta:
Spectrum graph of a temperature series which shows some correlation with the HMF has no power whatsoever at 11.86 years.
http://www.vukcevic.talktalk.net/HMF-T.htm
Geoff Sharp says:
November 16, 2011 at 2:18 pm
Because one record doesn’t agree with another is no reason to call one unreliable.
Lots of good reasons. They are both unreliable. Even a single record can show its unreliability [even if it is an average of many stations]. A single look at Silverman’s record for 1800-1948 shows this so clearly: http://www.leif.org/research/Aurorae-1800-1948.png
The green ovals outline particularly crass discrepancies between the sunspot number [red] and the auroral record. Critical here is, of course, that aurorae follow the sunspot cycle, but that we know they do from modern observations.
The aurora record as seen can occur when Kp values are low
No, not at mid-latitudes. In the very few cases that occurs, there was a magnetic storm the day or two before and it can take a few days for the effects to die down. So, the monthly or yearly count will still show a strong relationship between Kp and mid-latitude aurorae.
If one portion of the planet experiences an aurora while the planet average Kp value is low may just mean that portion of the planet is experiencing a localized phenomenon.
Mid-latitude aurorae only occur as a global phenomenon. They are the result of particles accelerated tens of thousands of km above the Earth and the magnetic effects from the currents are world-wide. Here are magnetograms from stations all over the world [the map shows where they were] during the great storm of 2003 that created widespread aurorae: http://www.leif.org/research/Halloween-Storm-Magnetograms.png
What if that area of the planet was a large area in the North Pacific that stayed cloudless for an extended period of time?
This has nothing to do with the aurora.
@ur momisugly Leif
you are making a lot of confusion.
Arguing that the data are wrong just because they do not fit your personal theory is a quite weak argument. All historical aurora records that we have are sufficiently correct for the purpose of my paper.
However, there is no disagreement among the records as you claim. The fact that some of them present a reciprocal negative correlation on the multidecadal scale is perfectly normal and in perfect agreement with what I say in the paper.
Your confusion is just due to the fact that in the paper I address only the Mid-latitude auroras from Europe and Asia plus the Faroes ones that match with the Mid-lat aurora. I did not discuss in details the other northern and american records because it would have made the paper much longer and it was useless for the purpose of the paper. The resason is because according to the resoning on my paper they could present a reciprocal behavior, if you think well.
About your argument based on magnetograms, it is naive. Tell me, when there is a Earthquake does everybody on the Earth notice it with his senses? Of course all machines around the world notice it. The same is with the aurora, everywhere the machines detect a signal , but only in specific regions the aurora can be see from the surface.
Sorry Leif.
Nicola Scafetta says:
November 16, 2011 at 7:31 pm
The same is with the aurora, everywhere the machines detect a signal , but only in specific regions the aurora can be see from the surface.
Let us try this from a different angle: you agree that if a strong aurora is seen in mid-latitude over Europe and Asia, there will be a magnetic signal everywhere. This means that such a strong magnetic signal is a good indicator of an aurora in that region [actually in any mid-latitude region – but let that slide for now] and that therefore the magnetic record is an objective, reliable indicator of mid-latitude aurorae, right?
M.A.Vukcevic says:
November 16, 2011 at 3:22 pm
This may come as a bit of disappointment
~
Been reading some IBEX articles mostly abstracts. I believe one of the models for the “Ribbon” at the heliosphere nose. Of which there were 6 now 7 model for what the interaction might be that creates that ribbon. Geeez that ribbon is long like a portion of coil spring boingggg..heh
But the idea that instead of a draping over the nose of the heliosphere, the ”interstellar magnetic field” it PASSSES THROUGH??
Now that might be a tangled mess but..solar system wide..whoaaa
~
Leif Svalgaard says:
November 16, 2011 at 8:32 pm
.. that therefore the magnetic record is an objective, reliable indicator of mid-latitude aurorae, right?
~
Yes, for the most part.
Geoff said sometimes the Kp is not there as an indicator yet the mid lat aurora are. Takes lots more particles in the uppper atmospere to light up that much more area..
One more aurora comment in vivid imagination mode..
It is said that the energetic particles bouncing around in the atmosphere that we seee when viewing aurora are bouncing between magnetic field lines, outlining or defining the field line.
Perhaps the Energetic particles IBEX sees is doing the same.. Defining field lines..
Carla says:
November 17, 2011 at 5:31 am
Geoff said sometimes the Kp is not there as an indicator yet the mid lat aurora are. Takes lots more particles in the uppper atmospere to light up that much more area..
Of 171 recorded aurora, only 4 were at low Kp at the time of the aurora, but the day before there was a geomagnetic storm, so Kp is still the indicator in all cases.
Carla says:
November 17, 2011 at 5:31 am
But the idea that instead of a draping over the nose of the heliosphere, the ”interstellar magnetic field” it PASSSES THROUGH??
The interstellar magnetic field cannot pass through the outward flowing solar wind.
Carla says:
November 17, 2011 at 5:52 am
It is said that the energetic particles bouncing around in the atmosphere that we seee when viewing aurora are bouncing between magnetic field lines, outlining or defining the field line.
Perhaps the Energetic particles IBEX sees is doing the same.. Defining field lines..
The particles follow field lines, don’t make the magnetic field lines. So ‘defining’ has to be thought of more precisely.
Carla
I devised the North Atlantic precursor more than a year ago, and havn’t written anything yet. Reason is that it in some parts it ‘follows’ closely the shape of the solar output, but only if it is delayed by number of years. Found similar with fluctuations of the Arctic magnetic field.
Only conclusion could be an external force (for both sun and the Earth) acting on the core, but in the case of the sun it takes much longer to propagate to the surface.
Hey doc, I hope that brings smile to your stern face, you need to be a bit more cheerful.
Not everything we think we know qualifies as ‘the knowledge’.
M.A.Vukcevic says:
November 17, 2011 at 9:19 am
Hey doc, I hope that brings smile to your stern face, you need to be a bit more cheerful.
Rather a cringe http://gallery.fanserviceftw.com/_images/e73b73f6660a5660bb9f0ad81d56205a/1377%20-%20animated_gif%20cringe%20miyamoto_shigeru%20shiggy.gif
That’s a dodgy link, my pc says ‘don’t touch’.
M.A.Vukcevic says:
November 17, 2011 at 9:54 am
That’s a dodgy link, my pc says ‘don’t touch’.
Safe version: http://www.leif.org/research/cringe.png
Leif Svalgaard says:
November 17, 2011 at 6:41 am
Carla says:
November 17, 2011 at 5:31 am
Geoff said sometimes the Kp is not there as an indicator yet the mid lat aurora are. Takes lots more particles in the uppper atmospere to light up that much more area..
——————————————————
Of 171 recorded aurora, only 4 were at low Kp at the time of the aurora, but the day before there was a geomagnetic storm, so Kp is still the indicator in all cases.
23% of all 171 records in Schroder’s study occur when Kp index is less than 5 (ie 4 and under) The records are taken all over Germany which has a latitude less than 55. I have included a link to the original table so those interested can see how many of those records occur just after high activity. Leif has stated that mid latitude aurora only occur at a Kp index of 7 or above which is clearly wrong, he also stated the low Kp values with aurora are directly after high Kp days which is also mostly wrong. I encourage people to look for themselves. It is obvious that the Kp value is not the only value important when dealing with mid latitude aurora.
http://tinyurl.com/2dg9u22/images/schroder.png
Geoff Sharp says:
November 17, 2011 at 6:23 pm
23% of all 171 records in Schroder’s study occur when Kp index is less than 5 (ie 4 and under) The records are taken all over Germany which has a latitude less than 55.
The smaller the latitude the higher must Kp be for aurora to occur.
The Kp=7 value comes from http://www.swpc.noaa.gov/Aurora/globeNE.html
It is obvious that the Kp value is not the only value important when dealing with mid latitude aurora.
It is not that Kp creates the aurora, but that statistically high Kp and midlatitude aurorae go together.
http://www.swpc.noaa.gov/Aurora/#kpmaps
Magnetic Latitude Kp
66.5 0
64.5 1
62.4 2
60.4 3
58.3 4
56.3 5
54.2 6
52.2 7
50.1 8
48.1 9
The Northern part of Germany has magnetic latitude 50 degrees, so Kp needs to be 8 or greater to have an aurorae overhead, but because of the great heights aurorae go to, you can now and then see one several hundred kilometers [several degrees] to the Nord. So, occasionally, a very extended aurora can be seen at somewhat lower Kp. You are misinterpreting Schroeder’s result. Read his last line: ” Finally, maximum auroral occurrence is around the sunspot maximum and minimum around sunspot minimum.” and “Figure 2 and Table 2 show that maximum numbers of auroras were observed around the maximum sunspot number years: 1947 and 1957-58. Minimum numbers of auroras were observed around the years of minimum sunspot numbers: 1952-54 and 1963-64; moreover, these events were mostly faint and short-lived. Thus, even in case of low solar activity, auroras may appear, but their occurrence frequency is very low.” That is the important point. “The connection between the appearance of auroras and geomagnetic activity (represented in the present report by the Kp-index), is well known (e.g Newell et al., 2009). There is an experimentally confirmed relation in the sense
that in the case of a higher Kp-index, auroras can be observed at more southern regions”.
So, bottom line: auroral activity at mid-latitudes follow the sunspot number and geomagnetic activity. This becomes even more apparent if yearly counts of the aurorae are used, as the inevitable noise decreases.
Leif Svalgaard says:
November 17, 2011 at 8:41 pm
So, bottom line: auroral activity at mid-latitudes follow the sunspot number and geomagnetic activity. This becomes even more apparent if yearly counts of the aurorae are used, as the inevitable noise decreases.
Your arguments have not proven to be substantiated.
1. Mid latitude aurora do not follow a 60 year period. FALSE.
2. Mid latitude aurora only occur above 7 Kp. FALSE.
3. Mid latitude aurora appear at low Kp only when a geomagnetic storm is experienced the previous day. FALSE.
4. Mid latitude aurora follow the sunspot number. FALSE.
Nicola’s research is vindicated and displays that all is not known when it comes to mid latitude aurora.
Geoff Sharp says:
November 17, 2011 at 10:43 pm
“So, bottom line: auroral activity at mid-latitudes follow the sunspot number and geomagnetic activity. This becomes even more apparent if yearly counts of the aurorae are used, as the inevitable noise decreases.”
Your arguments have not proven to be substantiated.
This is not my argument, but the result of decades of work by many scientists. Some of the [few] cases you have brought up are just the noise in the system. Schroeder again:
“Finally, maximum auroral occurrence is around the sunspot maximum and minimum around sunspot minimum.” and “Figure 2 and Table 2 show that maximum numbers of auroras were observed around the maximum sunspot number years: 1947 and 1957-58. Minimum numbers of auroras were observed around the years of minimum sunspot numbers: 1952-54 and 1963-64; moreover, these events were mostly faint and short-lived. Thus, even in case of low solar activity, auroras may appear, but their occurrence frequency is very low.” That is the important point. “The connection between the appearance of auroras and geomagnetic activity (represented in the present report by the Kp-index), is well known (e.g Newell et al., 2009). There is an experimentally confirmed relation in the sense
that in the case of a higher Kp-index, auroras can be observed at more southern regions”.
Nicola’s research is vindicated and displays that all is not known when it comes to mid latitude aurora.
His claim that mid-latitude aurorae occur most frequently at low solar activity is nonsense. Both observation and theory show this.
@ur momisugly Leif
Sorry Leif . You are competely misinterpreting my point.
First, I never denied in the paper and above that the aurora records present a decadal cycle in positive correlation with the decadal solar cycle. If you read above the initial comment to the article I clearly wrote
“During the solar cycle maxima the magnetosphere gets stronger so the aurora should be pushed toward the poles. However, during the solar maxima a lot of solar flares and highly energetic solar explosions occurs. As a consequence you see an increased number of mid-latitude auroras despite the fact that the magnetosphere is stronger and should push them toward the poles.
”
Which may not be very elegantly written, but clearly implies that I am saying the Mid-latitude aurora present a decadal cycle in positive correlation with the decadal solar cycle.
On the contrary my point is different and regards the 60-year modulation. Above I wrote “On the contrary, when the magnetosphere gets weaker on a multidecadal scale, the mid-latitude aurora forms more likely, and you may see some mid-latitude auroras even during the solar minima as Figure 2 shows.”
Second, Now let us look closely at your german record
http://www.geofisica.unam.mx/divulgacion/geofinternacional/iframes/anteriores/2011/04/6_schroder.pdf
This record covers the aurora from 1946 to 1964 and cover two solar cycles. Now you need to understand that from 1940 to 1970 my 60 year cycle was decreasing. According to what I wrote in the paper you need to look mostly at what is happening during the solar minima. From the paper of above the solar minima periods 1951-1954 and 1961-1964 where almost equivalent about the sunspot number. Also the aa index was almost equal during these two periods.
According your understanding of this phenomenon the two periods should be approximately equivalent about the aurora events. And aurora could be seen only at Kp>=8.
However, according my understanding of this phenomenon, because the 60-year cycle was in its decreasing trend, the solar minimum period 1961-1964 should have recorded more auroras than the previous solar minimum period 1951-1954. Moreover, the solar minimum period 1961-1964 should have recorded more aurora with a lower Kp index than the previous period 1951-1954.
Now, let us see the data to see which theory (yours or mine) is confirmed.
These are the recorded aurora from 1951 to 1954
Xp
01/05/51 7
02/05/51 7
25/09/51 8
07/10/51 8
28/10/51 9
These are the recorded aurora from 1961 to 1964
Xp
08/01/61 4
04/02/61 7
17/02/61 6
26/05/61 4
17/07/61 6
11/08/61 5
11/10/61 4
28/10/61 3
10/01/62 6
29/06/62 3
28/07/62 4
24/10/62 5
29/07/63 3
30/07/63 5
03/10/64 4
As you can easily see from the above numbers, the data agree with my expectations, not with yours. In fact, not only in 1961-64 we see much more german aurora than during the period 1951-1954 as my model predicts, but we often see them also with a very low Xp index 3, 4, 5 and 6 and always below Xp=8 which do not fit at all your theory of Xp>=8 for Germany (not even with the several hundred kilometer hypothesis jump, which should be more than 1500 Km to cover the 10 necessary degrees).