From the University of Hawaii ‑ SOEST:
Climate researchers discover new rhythm for El Niño
El Niño wreaks havoc across the globe, shifting weather patterns that spawn droughts in some regions and floods in others. The impacts of this tropical Pacific climate phenomenon are well known and documented.
A mystery, however, has remained despite decades of research: Why does El Niño always peak around Christmas and end quickly by February to April?
Now there is an answer: An unusual wind pattern that straddles the equatorial Pacific during strong El Niño events and swings back and forth with a period of 15 months explains El Niño’s close ties to the annual cycle.
This finding is reported in the May 26, 2013, online issue of Nature Geoscience by scientists from the University of Hawai’i at Manoa Meteorology Department and International Pacific Research Center.
“This atmospheric pattern peaks in February and triggers some of the well-known El Niño impacts, such as droughts in the Philippines and across Micronesia and heavy rainfall over French Polynesia,” says lead author Malte Stuecker.
When anomalous trade winds shift south they can terminate an El Niño by generating eastward propagating equatorial Kelvin waves that eventually resume upwelling of cold water in the eastern equatorial Pacific. This wind shift is part of the larger, unusual atmospheric pattern accompanying El Niño events, in which a high-pressure system hovers over the Philippines and the major rain band of the South Pacific rapidly shifts equatorward.
With the help of numerical atmospheric models, the scientists discovered that this unusual pattern originates from an interaction between El Niño and the seasonal evolution of temperatures in the western tropical Pacific warm pool.
“Not all El Niño events are accompanied by this unusual wind pattern” notes Malte Stuecker, “but once El Niño conditions reach a certain threshold amplitude during the right time of the year, it is like a jack-in-the-box whose lid pops open.”
A study of the evolution of the anomalous wind pattern in the model reveals a rhythm of about 15 months accompanying strong El Niño events, which is considerably faster than the three- to five-year timetable for El Niño events, but slower than the annual cycle.
“This type of variability is known in physics as a combination tone,” says Fei-Fei Jin, professor of Meteorology and co-author of the study. Combination tones have been known for more than three centuries. They where discovered by violin builder Tartini, who realized that our ear can create a third tone, even though only two tones are played on a violin.
“The unusual wind pattern straddling the equator during an El Niño is such a combination tone between El Niño events and the seasonal march of the sun across the equator” says co-author Axel Timmermann, climate scientist at the International Pacific Research Center and professor at the Department of Oceanography, University of Hawai’i. He adds, “It turns out that many climate models have difficulties creating the correct combination tone, which is likely to impact their ability to simulate and predict El Niño events and their global impacts.”
The scientists are convinced that a better representation of the 15-month tropical Pacific wind pattern in climate models will improve El Niño forecasts. Moreover, they say the latest climate model projections suggest that El Niño events will be accompanied more often by this combination tone wind pattern, which will also change the characteristics of future El Niño rainfall patterns.
Citation: Stuecker, M. F., A. Timmermann, F.-F. Jin, S. McGregor, and H.-L. Ren (2013), A combination mode of the annual cycle and the El Niño/Southern Oscillation, Nature Geoscience, May 26 online publication at http://dx.doi.org/10.1038/ngeo1826.
h/t to Dr. Leif Svalgaard
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“The fortnightly tide cycle entails equatorial water displaced toward the poles (the earth speeds up) and returning toward the equator (the earth slows back down) with negligible loss of energy. The 18 year cycle determines how much water moves toward and away from poles”
Thank you. This is what seemed probable to me but I have not had time to investigate and dig out proper references yet. Perhaps you could point me in the right direction.
As the amplitude of the moon’s declination increases and decreases it will draw water away from the equator towards low extra-tropical latitudes and back again. When this amplitude is lowest it will tend to concentrate water around the equator. When greatest it will draw it outwards.
Once the warm tropical waters are draw outwards they will enter the major oceanic gyres and be carried to high latitudes eventually influencing the polar regions. This will also leave lower, cooler waters exposed in the tropics which will warm towards the local equilibrium. This is like the typical La Nina phase where OHC is increased through exposer of cooler water and assimilation of a greater amount solar energy.
In the contrary phase the now warmed surface waters in the tropics will be concentrated towards the equator. This will increase the frequency of tropical thunder storms and evacuate heat to the troposphere. This is El Nino like patterns and involves loss of OHC .
As you have already pointed out these movements are of sufficient amplitude to produce a visible 18 year period in LOD. This implies two things. Firstly, that the displacement of the water is sufficient to require an adjustment in the angular momentum of the solid earth to compensate for the change in angular momentum of the water. This requires a boundary interaction between the oceans and the continents in an East / West direction.
Second, as the water moves towards the equator it moves to a larger radius and hence slows. This implies and eastward movement relative to the solid Earth. This is the movement which causes the boundary interaction affecting the solid Earth, that is visible in LOD.
The biggest ocean will meet the deepest and steepest continental barrier along the Western coast of South America. Since we are principally concerned with tropical waters this will be the northern end of the South American continental barrier.
In other words Peru, the birth place of the famous La Nina / El Nino events.
So, yes, the momentum exchanges are mostly reversible, the thermal implications not so.
Their computers discovered a 15-month combination tone between El Nino events and the pattern of sun crossing the equator. Interesting, but just how does this explain the mystery of “…why does El Niño always peak around Christmas and end quickly by February to April?..” The periods are incommensurate. But looking at temperature curves the mystery resolves itself without help from a 15 month combination tone because in real life El Ninos and Christmas rarely coincide.They claim that the Christmas El Nino ends quickly in February to April, which is about three months. Checking the record, the quickest ending El Nino I can find is the El Nino of 1988. That one took six months to wind down. Also, it just happens to be the one that Hansen promoted as the peak of anthropogenic warming to the Senate. The La Nina that followed it in six months lowered global temperature by 0.4 degrees from that world-beating high temperature Hansen was pitching. Actually these guys who wrote this article are no better than any of their predecessors, among whom we find both Hansen and Trenberth. Collectively there must be a thousand articles all trying to fathom out the secret of El Nino and failing. They all have some part of the El Nino story to tell but they don’t know where to go from there. They are like blind men trying to guess what part of an elephant they have gotten hold of and how to fit all together. Among other things, they have postulated an El Nino-like Pliocene climate which is an absurdity.Today there is no excuse for this because I explained it all in my book in 2010. El Nino is part of a resonant oscillation of ocean water from side to side in the equatorial Pacific. If you blow across the end of a glass tube you get a tone that is its resonant oscillation whose frequency depends on the dimensions of the tube. Trade winds are the equivalent of blowing across the tube and the ocean answers with its own resonant tone – about one El Nino wave every five years or so. This has been going on since the present configuration of Pacific equatorial currents has existed, which is to say since the Panamanian Seaway closed. Trade winds push the two equatorial currents west until they are blocked by the Philippines and New Guinea. This prevents them from reaching the Indian Ocean. As a result, their water piles up in that triangle and creates the Indo-Pacific Warm Pool – the warmest water on earth. When that pile of water is high enough gravity flow starts backward. An El Nino wave forms and moves east along the equatorial counter-current until it hits the South American coast. There it spreads out north and south and warms the air above it. Warm air rises, interferes with trade winds, mixes with the westerlies, and we notice that an El Nino has arrived. But any wave that runs ashore must also retreat. As the El Nino wave retreats water level behind it drops half a meter, cool water from below fills the gap, and a La Nina has started. As much as the El Nino warmed the air before the La Nina will now cool it. This balance is quite precise and is self-adjusting. Judging by satellite data the usual swing from warm El Nino to cool La Nina is approximately 0.4 degrees Celsius. This is not local temperature change I am talking about but world temperature change. It is about as much as fifty years of global warming will produce. If you compare temperature curves measured in North America, Europe, and Japan the El Nino peaks in all of them line up precisely. This much is basic. But now consider the long path it has to travel across the ocean, the time it takes to do that, and all the other things like cyclones also going on in the ocean, and you will understand why ENSO does not look like a perfect sine wave. It is possible, for instance, that something will stop the El Nino wave cold in its tracks as it is on the way to South America. What happens then is that its warm water, instead of spreading out along the coast, will spread out in the middle of the ocean and create an El Nino on the spot. Such an El Nino is called an El Nino Modoki or Mid-Pacific El Nino. It is an anomaly that can change the apparent frequency of La Ninas because the normal flow pattern of ENSO is disturbed. We have no idea what causes it but here is something worthwhile for these people to research instead of talking about a silly 15 month computer simulation. There is more. I suggest they study carefully pages 23 to 29 in my book.
]OK, I’ve managed to get a clear copy of figure and I’ve extracted the peaks with a reasonable degree of accuracy.
# PC1 peaks:
# px py freq years months
*P1 0.206 4.854 58.2
P2 3.759 45
*P3 0.404 2.475 29,7
*P4 0.589 1.698 20.4
P5 0.661 1.513 18,2 # poor def
*P6 0.782 1.279 15.3
# CP2 peaks
# px py freq years months
+p1 0.204 4.902 58,8
p2 0.371 2.695 32.3
+*p3 0.492 2.033 24.4
*p4 0.667 1.499 18
+p5 0.780 1.282 15,4
p6 0.991 1.009 12
*p7 1.294 0.773 9.3
p8 1.414 0.707 8,5
*p9 1.504 0,665 8
So how does that square up with my previous interpretations?
Here’s frequencies I found in SPD chirp analysis of west Pacific trade wind data:
http://climategrog.wordpress.com/?attachment_id=281
TW PC1 PC2
1.827a = 22m 1.698 = 20.4m
2.455a = 29.5m 2.475 = 29,7m
3.745a = 45m 3.759 = 45m
4.431a = 53m 4.854 = 58.2 m 4.90
5.424 = 65m
So the tentative QBO of 29.5m and the inferior “ENSO” of 3.745 spot on . The central period of 4.43 that I found differs significantly 4.85 however, and the long period around 5.4 does not appear.
Now looking at the side-bands denoted in grey in the paper there are three peaks each side. If this is amplitude modulation with (1-f) and (1+f) as marked we should find pairs adding to 2.0, approximately. p3,p9 and p7,p4 seem to conform.
For the first pair (1-f) and (1+f) are fairly symmetrical and give a modulation frequency very close to 2 years. The second pair is slightly off at one side but suggests an amplitude modulation of 3 years.
With evenly spaced 1,2 and 3 years this may just reflect auto-correlation in the data with last years changes affecting this years. The spectral analysis should be repeated using the first difference of the time series (rate of change) to eliminate this.
It is also noted that p1,p3,p5 are symmetrically disposed:
As A.M. side-bands: 3.4736 2.0330 -3.4704
The two side frequencies are also strongly present PC1 as P1 and P6 again modulation by 2.0 years suggests autocorrelation in the data.
The centre is close to the 3.759a found here and in the trade wind data I looked at. however it is probably too far off the be attributed as being the same thing. if the analysis is correct.
Now since p5 and P6 are the key frequency that the study focussed on (the 15months) I would want to be convinced that this is not just a result of the auto correlation that is present in nearly all climate data.
Testing the data for the presence of autocorrelation and stationarity are standard checks before doing this sort of analysis. Now unless I missed it, I did not see any mention of this in the S.I. that did go into quite some detail about the method.
Taking the first difference of the monthly data will remove the autocorrelation without removing the hypothesis physical loop of 15 months if it is real.
For now I think there are too many integer multiples of 1 year coming out for me to have too much confidence this is real.
One of the authors, Axel Timmermann, has contacted me by email to inform me:
“You confuse a BEAT (linear superposition) with COMBINATION TONE ( a nonlinear feature; e.g. the square of the sum of two cosines)” though he did not specify exactly what non-linear function they were using or even if they had anything more specific than “a nonlinear feature”.
I would say he is confounding amplitude modulation and superposition in the physical domain. Though I would be happy if he can prove me wrong on that.
The work with EOFs and complex climate models is interesting and I think the authors are right to be looking for feedbacks and loops in this key region but I’d like some basic signal processing checks before they go in with the heavy artillery.
I found some interesting patterns is the trade wind data which should not be too different from what they are using so I’m rather surprised to see similar kind of structure but with the numbers not tying up and a preponderance annual multiples.
I also prefer not to use anomalies in spectral analysis unless is it unavoidable.
Looking at the authors’ claim of a (1+f) (1-f) pair of periods around 10 and 15 months it seems the peaks that come closest ot that are P6=p5 and p7
However, p7 is clearly part of an AM triplet indicating modulaiton of between 1y and 3y periods
p4 0.667 1.499 18
p6 0.991 1.009 12
p7 1.294 0.773 9.3
Equally,p5 is part of a triplet arising from 2 year and 3.47 years
p1 0.204 4.902 58,8
p3 0.492 2.033 24.4
p5 0.780 1.282 15,4
It is unclear why the authors fail to spot these clear triplets, instead suggesting that there is 10/12/15 month triplet. Using the peaks in their data this gives an improbably assymetric “triplet”.
As A.M. sidebands: 4.5461 1.0000 -3.4053
Before invoking exotic and ill-defined “non -linear” combinations tones it would seem more sensible to correctly apply basic linear interference relationships that have been understood for centuries.
Before investing time in esotric EOF analysis and complex yet incomplete computre models of climate, it would seem appropriate to investigate simpler, traditional spectral analysis techniques such as spectral density derived from the fourrier transform of the autocorrelation function as I did on the West Pacific trade wind data.
As I said above , I think the authors are looking in the right direction but the executions and interpretation of the analysis shown in this paper seems to have serious short-comings.
Greg Goodman says:
May 29, 2013 at 3:18 pm
============================
Sorry I didn’t get back sooner. One should think of the fortnightly tide as a slowly forming bulge of a few inches, involving latitudinal displacement of water of only a few inches. It affects LOD by a millisecond, plus and minus. Nor whale nor minnow can catch a ride on this wave. The appropriate wave speed units are millifurlongs per fortnight. –AGF
I see I’ve been misusing the term “fortnightly,” which correctly refers to the phasing of lunar and solar tides. What I’ve been calling fortnightly is correctly called “zonal.” Of course the zonal tide is of fortnightly frequency but is determined by the moon’s position relative to the earth’s axis rather than to the sun. –AGF
agfosterjr says:
One should think of the fortnightly tide as a slowly forming bulge of a few inches, involving latitudinal displacement of water of only a few inches. It affects LOD by a millisecond, plus and minus. The appropriate wave speed units are millifurlongs per fortnight.
Thanks for the information. You seem to have detailed knowledge on this.
Is is possible to express that Sverdrup total for each hemisphere?
How does the magnitude of this effect vary with the variation in the declination angle? As the mean position of the oscillation increases there must be a net flow away from the equator. This is the period I believe you referred to as being a visible 18 year variation visible in LOD.
With the huge inertias involved it is clear that the amplitude of the response will drop off sharply with frequency. Conversely, it could have a much larger amplitude response to a persistent tendency that continues on annual to decadal scales in the same direction.
On that time scale it may even express itself as a slow tide in the thermocline and halocline. Are you able to comment on that?
It’s a while since I did any work in furlong but unless I’m mistaken one millifurlong per fortnight is about 50 km in 9 years. Can that be expressed in Sverdrup for each hemisphere?
I’m just trying to a handle on the orders of magnitude here. Your apparent familiarity is most helpful.
many thanks for your comments.
What I think it perhaps more physically relevant is the precession of the lunar perigee. I say this because I see several periodic variations in SST, trade winds and the like that are obviously related to 8.85 (4.43) years rather than 18.6 (9.3) years.
Also having more pull in the Northern hemisphere and less in the south (and vice versa) is a more persistent influence than a drift in the magnitude of a symmetrical oscillation.
I think that is factor that needs evaluation.
http://climategrog.wordpress.com/?attachment_id=206
It the lunar perigee cycle the origin of the mysterious “polar see-saw”?
Greetings, Greg:
For magnitude of tidal bulge constituents see Wikipedia sv. “Earth Tide” at
http://en.wikipedia.org/wiki/Earth_tide
There you may note vertical and horizonal components at an 18.6 year frequency of 17 and 2.3mm respectively. The tidal bulge varies usual between one and two feet, and over the course of a siderial lunar revolution moves twice from from perpendicular to the earth axis to an angle of roughly 60-70 degrees to the axis. When the bulge is parallel to the axis the bulge has no measurable effect on LOD, but when it has a strong north and south component it decreases LOD by half a ms. See:
http://hpiers.obspm.fr/eop-pc/index.php?index=realtime&lang=en
The bulge is a standing wave of variable magnitude. Daily tides involve very little current except along shallow coasts and rivers, and fortnightly tides involve even less. According to the Wiki article the zonal tide has zero magnitude at 35 degrees latitude, as tropical waters rise and fall while polar waters fall and rise by a few inches. The earth’s moment of inertia varies by one part in a hundred million as the lithosphere and hydrosphere deform latitudinally. Moving water from the equator to the poles is like moving an electric current between transformers on power lines. Though the current moves a hundred miles at the speed of light, the electrons themselves move only a few inches. Likewise the zonal tide moves water just a few inches in a week, so that using sverdrups for units would be overkill. “Furlongs per fortnight” were units my Dad relayed to me, spoofing US resistance to SI units.
The slight tidal current is distrubuted throughout the depths of the ocean and is capable of creating turbulence at great depths along the coast, and of creating standing waves between density gradients, but as far as I can tell, is quite incapable of affecting ocean currents to anything but a negligible degree. With tides the sea is a wave carrying medium for the most part. You may want to take a look at Chao et all:
http://gji.oxfordjournals.org/content/122/3/765.full.pdf
Regards, –AGF
Greg, I streamlined a concise intro here:
http://wattsupwiththat.com/2011/04/10/solar-terrestrial-lunisolar-components-of-rate-of-change-of-length-of-day/
The Gross (2007) reference includes a detailed tabulation of LOD components.
I’ve learned a few things since then. Here’s a key tip:
Take due care to note when solar variations reverse phase on terrestrial resonance frameworks. Pay particular attention to asymmetries (gradients) and their integrals (cumulative flow).
__
I have new insights into the structure of volcanic indices — details another week or month …
“There you may note vertical and horizonal components at an 18.6 year frequency of 17 and 2.3mm respectively.”
Thanks , but that’s the _solid earth_ tide not oceanic tide.
I agree sverdrup would not be much use for the displacement of the crust.
What I’m trying to evaluate is the magnitude of the volume of water displaced by the precession of the lunar perigee. since that only moves from north to south once in 8.85 years it will pass the tropics twice in that time and could explain the strong 4.43 year cycle I identified in the wind data.
Greg:
Lunar-induced solid body tide amplitude =41 cm.
Lunar-induced ocean tide = 58 cm (rel. to solid earth).
Solar induced tides are ~ 1/3 of these values.
Theoretically calculated at:
http://astro.cornell.edu/academics/courses/astro6570/Tidal_evolution.pdf
Have you seen Keeling and Whorf?
http://www.pnas.org/content/94/16/8321.long
I don’t believe a word of it, but at least a mechanism is suggested, and LOD is not involved.
But yeah, I was full of it. Besides my earth tide confusion the fortnightly tide does involve a few sverdrups, but that’s irrelevant. You can’t interfere with the tide without without taking energy from it, which reduces its reversibility and slows down the earth. So the available energy is limited to 4TW, 5 orders of magnitude lower than solar energy. Moreover there is no such thing as an 18 year tide flow. It is a fortnightly flow with an amplitude that varies over 18 years. In terms of signal processing the zonal tide is a carrier wave modulating a lower frequency of 18 years.
Correct me if I’m wrong. –AGF
“You can’t interfere with the tide without without taking energy from it, which reduces its reversibility and slows down the earth. ”
No, you’re still not getting it. This is NOT about extracting energy from the tides. It is about horizontal tidal displacement of water in and out of the tropics.
There is an 18year tide since perigee moves up and down in latitude over this period. This is distinct from variation in the magnitude of the lunar declination.
The solid Earth tidal components you linked to show even a small vertical movement on this scale.
This may indicate the wet tide is small but that does not necessarily follow. If any of these frequencies are close to a resonant frequency of the oceanic basin it could build up to a significant signal.
If there is an effect from lunar perigee cycle of 8.85 years this will pass the tropics twice as often (similar to the solar variation at the tropics). That would create a signal of 4.43 years which is exactly what I extracted from the W. Pacific trade wind data.
It is the central frequency of circa 3.7 and 5.2 years which are the splitting of 4.43 by a longer periodicity. That very likely accounts for the “3 to 5 year” scale usually attributed to ENSO. In which case ENSO is basically a lunar driven bimodal oscillation.
It is at least possible that the long term modulator is the solar Hale cycle.
The Keeling paper is very interesting. It seems to be heading in the same direction but has not made the link with all the resonances I’ve found here.
Again , his observations of a different frequency around 1920 is the same thing I was discussing in this article:
http://climategrog.wordpress.com/2013/03/01/61/
The short frequency is because the lunar and solar signals are out of phase. That seems to be what Keeling is saying. I’ll have read it fully.
Thanks for the link.
Greg Goodman says:
May 30, 2013 at 2:31 am
“Looking at the authors’ claim of a (1+f) (1-f) pair of periods around 10 and 15 months it seems the peaks that come closest to that are P6=p5 and p7
However, p7 is clearly part of an AM triplet indicating modulation of between 1y and 3y periods
p4 0.667 1.499 18
p6 0.991 1.009 12
p7 1.294 0.773 9.3
Equally,p5 is part of a triplet arising from 2 year and 3.47 years
p1 0.204 4.902 58,8
p3 0.492 2.033 24.4
p5 0.780 1.282 15,4
”
The 3.47 years was found in figure 2 from the paper in this article and in my spectrum of trade winds. Almost exactly the same figure : 3.745 cf 3.759
This is also part of an AM triplet based on the lunar perigee that I found in TW data:
3.745; 4.431, 5.424
I’ve just checked back on my power spectrum of Arctic sea ice areal acceleration and find the exact same thing !
2.019 , 1.2868 and there is also 4.802 but very small.
The whole climate is ringing like a bell.
Okeedokee. Assuming a flat rectangular earth with an ocean 3×10^7m wide, 10^7m long and 3×10^3m deep, with a peak to peak flat–linear–seesaw tide of 1m over a period of 1 week, I calculate a flow of half a sverdrup and an average horizontal/longitudinal water displacement of 2.2km. I think this might generously represent planet earth within an order of magnitude–maybe too high by an order of magnitude. Would you care to replicate my calculations? –AGF
New:
http://img441.imageshack.us/img441/2314/sunspotsvei.png
In concert with what I’ve pointed out above, that’s enough info to crack the code of NPI and July & August ENSO.
“Ocean temperatures in the upper 250 m in the northern North Pacific (60°N, 149°W) increased by more than 1°C from 1972 to 1986 but are now decreasing. Subsurface temperature anomalies are well correlated (∼0.58) with the air temperature anomalies at Sitka, Alaska; hence the coastal air temperatures can be used as a proxy data set to extend the ocean temperature time series back to 1828. Up to 30% of the low-frequency variance can be accounted for with the 18.6-year nodal signal. Additionally, spectral analysis of these air temperature variations indicates a significant low-frequency peak in the range of the 18.6-year signal. Similar low-frequency signals have been reported for Hudson Bay air temperatures since 1700, for sea surface temperatures in the North Atlantic from 1876 to 1939, and for sea level in the high-latitude southern hemisphere. The water column temperature variations presented here are the first evidence that the upper ocean is responding to this very long period tidal forcing. An enhanced high-latitude response to the 18.6-year forcing is predicted by equilibrium tide theory, and it should be most evident at latitudes poleward of about 50°. These low-frequency ocean-atmosphere variations must be considered in high-latitude assessments of global climate change, since they are of the same magnitude as many of the predicted global changes.”
http://onlinelibrary.wiley.com/doi/10.1029/92JC02750/abstract;jsessionid=09ED4271D96D3E8EA5A6E71BF2D43E88.d02t02
Now with the moon on the sunny side I calculate 3000 sverdrups and 22km displacement for my flat earth tides, which ventures dangerously close to the realm of significance. Therefore I will concede the possibility of tide cycles affecting weather, however minutely.
Before I give up I will note a couple of things I learned along the way: 1) Most of the ocean is too shallow for a semidiurnal tidal bulge/wave to keep up, so that the tides set up their own oscillations according to the depth and size of their basins. The case is different with zonal tides, whose wave speed is easily handled by ocean depths. 2) If my flat earth representation is true to life and Hansen’s sea level predictions come to pass, we may expect considerable alteration in tidal behavior–maybe the end of the world as we know it. –AGF
“Now with the moon on the sunny side I calculate 3000 sverdrups and 22km displacement for my flat earth tides, which ventures dangerously close to the realm of significance. Therefore I will concede the possibility of tide cycles affecting weather, however minutely.”
Interesting, what caused the huge change from your earlier estimations? Could you explain what tides these figures relate to?
The findings in the paper you linked to and Keeling’s paper seem to confirm my gut feeling about this. Significant to note the dates: 1993 an 1997.
I seems that .prior to MBH 1998 and all the stupidity created by IPCC TAR and the hockey stick, there was some normal, boring and realistic science being done in this field.
“The case is different with zonal tides…” That is the circa “fornightly” tides if I recall you correctly, so your figures would be even bigger for 18.6 years, no?
Maybe I’m not following what you meant.
Paul Vaughan says:
http://img441.imageshack.us/img441/2314/sunspotsvei.png
In concert with what I’ve pointed out above, that’s enough info to crack the code of NPI and July & August ENSO.
===
Sadly, not enough to crack the code of your cryptic post and label free graph. 😉
Looks like you have some significant pattern there. What’s pi, what’s the polar plot coords, what’s it all about?
Greg Goodman says:
June 2, 2013 at 12:06 pm
“Interesting, what caused the huge change from your earlier estimations?”
Huge mistakes.
“Could you explain what tides these figure relate to?”
Zonal tides. I unwound the northern hemisphere onto a plane.
“’The case is different with zonal tides…’ That is the circa ‘fornightly’ tides if I recall you correctly, so your figures would be even bigger for 18.6 years, no?”
No. The zonal tides are real. Like I told you before, there is no such thing as an 18.6y tide. The 18.6y cycle is an oscillation in the amplitude of the zonal tide. Semidiurnal tides try to travel at earth rotation speed, but they can’t. Zonal tides can. Conventionally so called “fortnightly” tides are artifacts–beat frequencies–of the semidiurnal lunar and solar tides, so that they can’t keep up either. –AGF
One thing I picked up on in Keeling’s paper was interference between 18.6 and 8.85 produces almost exactly 6 years. Now since most of these cycles seem to double up at the equator due to the double pass, this would be almost exactly 3.0 years.
That is the one major frequency that was not accounted for from the wind speed analysis.
http://wattsupwiththat.com/2013/05/26/new-el-nino-causal-pattern-discovered/#comment-1321186
p7 and p4 in the peaks I extracted from Stuecker et al 2013 and taking their suggestion that this is amplitude modulation produces 3 years
I also found 3.047 years in doing the spectrum on wind speed squared (the energy of wind).
http://climategrog.wordpress.com/?attachment_id=283
Being so close to an integer value I was looking for an explanation related to the annual cycle (and was not getting too far). Seems I was looking in the wrong direction.
It appears that most of the peaks in this wind data can be traced back to 8.85 and 18.6 years.
Keeling’s objective paper from 1993 was correct it would seem. Unfortunately climates science has been derailed for most of the following 20 years.
Excuse the sloppy syntax: zonal tides can’t travel at earth rotation speed, but they can travel easily at fortnightly periods–a few thousand furlongs per fortnight. –AGF
General comment (to everyone) to correct a tired old (often seemingly deliberate) misrepresentation: LOD is not suggested as a climate driver. It’s a climate indicator with exceptional diagnostic utility since it’s so well-constrained in aggregate by the laws of conservation of angular momentum & large numbers.
______
Greg Goodman (June 2, 2013 at 12:13 pm) asked about:
http://img441.imageshack.us/img441/2314/sunspotsvei.png
“What’s pi, what’s the polar plot coords, what’s it all about?”
2pi radians = 1 cycle
That’s VEI summarized by solar cycle phase (2 different views of same thing in bottom panel).
…But as I & others have cautioned: Temporally-global summaries are severely misleading — it’s worthwhile to look at them, but stopping there leads to patently false inferential assumptions.
Pay very careful attention to the phase relations of the 11 solar activity cycle and the 9 year solar asymmetry cycle:
http://img268.imageshack.us/img268/8272/sjev911.png
When the 9-11 phase contrast ventures away from 0, stratospheric effects (which are dependent on large scale circulation) are minimized:
http://img829.imageshack.us/img829/2836/volcano911.png
The role for the lunisolar, annual, semi-annual etc. cycles is aliasing & resonance. It’s solar activity & asymmetry that do the driving. May I suggest devoting some attention to temperature gradients? As Jean Dickey emphasizes: Mass, temperature, & velocity are coupled. Lunisolar forces rhythmically move mass, but the sun maintains the shifting & cycling gradients that drive large scale flow on this (framed resonance & aliasing) background. Remember that the solar system, the sun, & the earth-moon system share common (confounded) timing frameworks. It’s important to note when the solar amplitude & asymmetry inputs of commensurate or nearly-commensurate period gradually change frequency and/or abruptly reverse phase relative to one another &/or the local framework. I have illustrated this crucial detail using both wavelets and nonparametric rank stats in the past, but perhaps it will be necessary to reinforce this lesson many more times.
One final note: There’s actually one more important feature of the 9 year solar asymmetry cycle that I’ve not yet illustrated. It will be visually obvious to an astute observer from careful inspection, but I realize it won’t be obvious to most. When time permits, I’ll illustrate further.
agfosterjr says:
Excuse the sloppy syntax: zonal tides can’t travel at earth rotation speed, but they can travel easily at fortnightly periods–a few thousand furlongs per fortnight. –AGF
So none of these gravity waves can travel fast enough to “follow” the moon on a 24h scale and the whole notion of a tide “bulge” that is dragged around the globe (relative to the earth’s surface) causing high tides at its passage is a totally erroneous.
What actually happens is a periodic perturbing force which sets up complex wave patterns that are reflected off run along continental boundaries as Kelvin waves, interfere with one another and resonate. Thus being more dependant up on geography of the basin concerned than the position of the moon at any one time.
The tidal bulge myth seems pervasive even in university level texts I have been able to find ( as well as , of course, Wankipedia pages ), yet it is nowhere to be found in tidal records.
So there is a strong M2 constituent in all tides but there is no “bulge” that passes any location on Earth. The phase of the M2 constituent at any location is totally dependant upon the geography of the basin.
Thank you for pointing out the wave speed argument which helps to clarify this.