## Solar Cycles, Ice Ages, and Albedo

Posted: April 8, 2011 by tallbloke in solar system dynamics

While I’ve been on job training, house maintenance, vehicle restoration, food production and science sabbatical, Tenuc and Roger A have started an interesting conversation on the suggestions thread. I had reached a point where I couldn’t see the forest for the trees, and have taken time off to do practical work I’d neglected while the science mulls over. I’ve also been reading Miles Mathis book ‘Un-Unified Field’ closely and I’ll be formulating a post about planetary mass and charge when I can find time. Thanks to all for keeping this blog alive while I’m wrapped up in other affairs.

1. Tenuc says:

Couple of interesting and pertinent papers on solar activity and climate from the Miles Mathis collection, could for the basis for a useful discussion here, I think…

The Hole at the Centre of the Sun.
“…by this equation we can find the fraction that goes to charge, which is 15%. That leaves 85% of the energy of the Sun produced by fusion. That makes sense, because it explains why all this loss of charge energy doesn’t cause the Earth to freeze over like Neptune…”

http://milesmathis.com/sunhole.html

How the Charge Field Causes the Ice Ages
“…Over time, the high end of the Solar disk makes a full revolution, returning to its original position. This is one cycle, and it is this cycle that takes about 23,000 years. But the nodes will be in line with the galactic core in two positions: when the high end is at ¼ and ¾. Or, if the galactic core is north, the nodes will line up with it when the high end is east or west. And so we get an alignment every 11,500 years or so. Alarms should be going off in your head now, because that number is already an important one in the history of ice ages. According to the math of many, interglacials have lasted about 11 thousands years. This is where that number comes from. 11.5 is half of 23…”

2. Roger Andrews says:

Hi Tenuc

Agreed. Might as well go with this.

Mathis’ theory implies sinusoidal ice-age cyclicity, but the plot of the Vostok ice core record he presents shows a clear sawtooth pattern, with the recoveries from ice ages being much more abrupt than the descents. This suggest to me that while the sun may provide the push, something else provides the shove.

Maybe dust?

http://serc.carleton.edu/images/eslabs/cryosphere/vostok_ice_core_data.png

3. Tenuc says:

@Roger – I agree, the fall in temperature is slower than the previous rise and has a distinctive and fairly regular saw-tooth profile. I don’t see a link to CO2 and wonder if the eratic link with dust could be a sympom of the drier climate during deep glaciation?

It is interesting that the slope of maximum temperature during the decline show almost the same approximate trend, while the minimum trend varies somewhat…

http://www.ianschumacher.com/img/boundaries.png

4. Roger Andrews says:

Tenuc

Don’t know what the gradients mean, but more dust = less incident sunlight = cooling.

Which brings up an issue that everyone seems to have forgotten about – “global dimming”. A 2008 JGR paper on this by Wild (http://www.leif.org/EOS/2008JD011470.pdf) notes that while TSI hardly varied between 1980 and 2000, solar radiation incident at the Earth’s surface increased by maybe 5 w/sq m, presumably because of decreases in aerosols and cloud cover. It also shows some very interesting global dimming/brightening/surface air temperature relationships (see Figure 9). I think this would also make a good thread if Tallbloke were around to post it.

1. Malaga View says:

PS
From my perspective Miles Mathis incorporates two other very important basic ingredients:
Kristian Birkeland – http://www.plasma-universe.com/Birkeland_current
Hannes Alfvén – http://www.plasma-universe.com/Hannes_Alfv%C3%A9n

2. tallbloke says:

Hi MV.
Yes, the fundamental unification of mass and charge in Miles theory opens up a lot of possibilities for investigating interplanetary and interstellar forces.

3. Roger Andrews says:

Tallbloke:

Welcome back.

I’m currently involved in a work project but will get back ASAP.

4. Douglas DC says:

I haven’t been by for a while-how’s the TVR going? Here in NE Oregon I have had
FIVE days in a row with morning snow. I am getting tired of the AGW religion.
I have to face a Warmist almost daily at work who says: “The warm is cold the cold, warm.
sayeth the Profit…” as he gets off of his studded tire bicycle…
he can’t see something bigger going on here…

5. P.G. Sharrow says:

The electrical charge into the sun rides on the back of “gravity”. “Gravity” or charge or aether is being sucked or pushed into matter. Plasma does not fuse, the last thing that plasma wants to do is fuse. Atoms are built one neutron at a time. Neutrons are hydrogen atoms that have been compressed down so that the negative charge and positive proton mask one another. Electron shells repel one another, protons repel one another. Only a weak negative surface neutron can slip through the strong negative electron shell and cozy up to the strong positive proton and fuse to the nucleus. The aether charge “gravity” provides the energy that compresses the hydrogen to neutron and spins up the internal angular momentum of the proton that increases the mass/inertia of the resultant neutron. pg

6. P.G. Sharrow says:

“Dust” in the Greenland ice record.

An open arctic ocean could lead to the following scenario.

Heavier “lake effect” snows on the land around the arctic ocean causes change in albedo and decreases heating of the land and air over it. Lose of energy to the northern atmosphere by condensation and freezing warms the polar area, ( less intense cold) and cools the high latitude land areas. As the Arctic ocean evaporates it sucks in more “warm” water from the south that helps to keep it open as well as increased salinity that reduces freezing temperature of that oceans water. This results in more “lake effect” snow on the land and additional albedo changes as snow accumulates farther south. This will continue until the ocean level becomes too low to replace the evaporation from the arctic and it cools down and freezes over completely. Now the entire area turns into a cold desert as is the Antarctic. The Antarctic is surrounded by ocean and is relatively stable. The Arctic is surrounded by land and is unstable. South of the great northern ice sheet is cold and desert like with great dust storms. In time (a long time) the ice sheet is no longer white snow but dirt covered muskeg. The change in albedo causes the cold land and atmosphere to heat up. The warm storm track moves north and warm wet storms speed up the end of the “ice age” and refills the oceans. Interglacial until the Arctic melts and gets warm enough to start this over. All we need is a quiet sun for long enough time to get the second heavy snow winter on top of the first.

7. Anything is possible says:

In response to PG Sharrow at 1:49pm :

I agree with the first part of your analysis : My theory is also that less ice in a warmer Arctic Ocean is a pre-requisite for the onset of glaciation – where else is the required moisture going to come from?

I also agree that the high northern latitudes – especially Northern Canada, become cold deserts – and this IMO, plays a key role in the ultimate disintegration of the continental Ice Sheets.

However, I think you are over-estimating the role of albedo. Think topography. The presence of a 2-mile thick ice sheet not only reduces sea-level by 150m, but raises all of Canada to 10,000 feet above sea level – another Tibetan plateau.The effect on surface temperatures and atmospheric circulation would be profound.

I don’t see the climate of the areas south of the great northern ice sheets being “cold and desert-like with great dust storms” either.

Geological reconstructions suggest that the southern USA and Mediterranean still had similar temperatures to today, even at the height of the last glaciation. This leads me to believe that Ice Age summers over the USA and Central Europe would still have been warm enough to cause a great deal of seasonal melt of snow and ice. If so, there would need to be prodigious amounts of snowfall during the winter months to compensate for this, and sustain the ice sheets for thousands of years. I think the huge temperature contrasts over comparatively short-distances – say between the Gulf of Mexico and the Great Lakes or Southern Spain and the North Sea – which must have existed would have provided the perfect recipe for just that.

Under this scenario, the continued existence of continental ice sheets would be highly dependant on receiving the requisite amount of winter snowfall – driven by extreme temperature contrasts between the heart of the ice sheet and the temperate mid-latitudes – to compensate for summer melt. If the height of the centre of the ice sheets (our cold deserts) were gradually reduced due to precipitation starvation, temperature would rise, and contrasts could be reduced enough to send the ice sheets into a negative mass balance (summer melt exceeding winter snowfall) with the resulting positive feedback loop causing rapid disintegration.

I realise all this is very highly speculative, but this stuff fascinates me, so I offer no apologies for that (:-

Any feedback will be read with great interest. TIA.

8. Tim Channon says:

If “prodigious amounts of snowfall” and “great deal of seasonal melt” then the geologic record must show a prodigious amount of erosion.

Does it?

9. Gray says:

http://milesmathis.com/ice.html

This is interesting stuff and appears to dovetail with the 4627 year ‘all synod’ period with a half periodicity of 2313 years.

10. Anything is possible says:

Tim Channon says:
April 9, 2011 at 2:21 pm
If “prodigious amounts of snowfall” and “great deal of seasonal melt” then the geologic record must show a prodigious amount of erosion.

Does it?

_____________________________________________________________________

Good question.

I don’t think anyone can be 100% certain exactly what Central Europe or the Northern USA looked liked before the onset of the last glaciation, but there is overwhelming evidence that the environments of both regions were profoundly altered during the last Ice Age.

On that basis, I’m going to say “yes”.

11. Roger Andrews says:

Anything is possible:

About forty years ago (I think) Maurice Ewing (I think) came up with the theory that ice ages begin when the Arctic Ocean becomes ice-free, which results in increased winter snowfall over Siberia and Northern Canada, and end when the Arctic Ocean freezes over again, which chops off the supply of moisture. I don’t remember him saying anything about increased temperature gradients between higher and lower latitudes, but these could indeed amplify the rate of ice growth and retreat.

They could explain something else too. Higher temperature gradients = higher pressure gradients = more wind = more dust = cooling. This matches the dust-temperature correlation in the Vostok record. (I read somewhere that the Vostok dust came from the Gobi desert, but I’m not sure how one tells Gobi desert dust apart from any other desert dust. Trace elements, maybe?)

I think this kind of “speculation” is important because it’s difficult to relate the sawtooth pattern in the Vostok ice core record to long-term solar changes. According to this record we don’t descend into or emerge from an ice age in a smooth, sinusoidal fashion; we hit some kind of a tipping point and everything abruptly changes direction. What causes the tipping? It has to be some terrestrial change, like the pack ice melting in the Arctic, or a change in the MOC, or whatever. And it doesn’t happen just once very 110,000 years. As Mathis points out, “sub-glacial” episodes occur about once every 11,000 years in every glacial cycle, and these seem to be tipping point-related phenomena too.

12. Tim Channon says:

Another sanity check if there is a precipitous volume of snowfall is ice layer thickness and signs of rapid melts. I seem to recall the later produces particular patterns, makes a mess.

Overall the whole ice thing makes me nervous, too many proxy and assumptions.

13. Tenuc says:

Just thought of something else. Could the Earth be getting a proportion of its energy from the galactic charge field? If this is the case, then our planets orientation would also have an effect of modulating the solar effect, sometimes acting in concert and sometime against.

The size of the wobble could vary over time in a non-linear way as the enormous mass of the NH ice sheets causes unbalance to axial spin. This in turn produces the quasi-cyclic sawtooth pattern of sub-glaciation events every ~11,00o years?

14. Gray says:

Miles is saying the Sun becomes more or less active as it orients towards or away from the Galactic plane. The Sun emits its undulating charge field from the equator. One supposes the planets are then affected by the Solar charge field in a similar and possibly synchronous fashion.

We see the Galaxy set out in a logarithmic spiral fashion due to the activity of the Galactic core and the Solar System mimics this with the planets arranged logarithmically due to Solar activity.

The current minimum has shown how quickly the Sun becomes inactive and how rapidly that affects Northern Hemisphere cooling in particular. The buffer against this would appear to be ocean temperatures being high initially (as they are now) ultimately allowing a relatively slow descent into ice age conditions as the Sun goes into long term hibernation and creating conditions for high volume snowfall.

11,000 years later the oceans are once again cold and the planet is arid, melting of the ice pack and warming of the oceans can take place without the volume of snowfall which marked the descent into a cooling period.

15. Malaga View says:

@ Tenuc
Could the Earth be getting a proportion of its energy from the galactic charge field?

I assume there is a indirect or direct connection… but I guess we really need a copy of the “wiring diagram” for the solar system… I wonder about what happens when the circuit receives more charge… could the gas giant start to glow?… could the gas giant magnetic fields change? could the orbit of comets be change? could all sorts of geomagnetic phenomena start to wake-up? My guess is we have to keep a very open mind to all sorts of possibilities…. perhaps the alignment to the galactic charge field acts like a dimmer switch.

16. Malaga View says:

@ Tenuc http://milesmathis.com/ice.html
1) He does not pretend to know it all.
2) He looks for real, tangible mechanical explanations.

Once again, I have shown you that mechanics is the answer. I haven’t discovered the whole answer yet, and don’t expect to. But I have shown you the framework for the right answer. Giving charge a real presence in the field, giving the photon a real presence in the field, and finding the charge field in the field equations of Newton and Einstein are the pillars of this framework. The fourth pillar is keeping that charge mechanical, by explaining every motion and every force and every interaction in terms of collisions—collisions that can be diagrammed. No borrowing from the vacuum, no broken symmetries, no virtual particles, no undefined fields, no forces at a distance, no hidden variables, no hiding behind the math.

If only the galactic gatekeeper et al kept such an open mind…

17. Roger Andrews says:

Gray:

“The current minimum has shown how quickly the Sun becomes inactive and how rapidly that affects Northern Hemisphere cooling in particular.”

Since the peak of solar cycle 23 in 2001 sea surface and troposphere temperatures in the NH have remained about the same and surface air temperatures have actually increased. In the SH all three have stayed about the same.

The abrupt decrease in surface air, troposphere and sea surface temperatures over the last few months could of course have had a solar component, but it’s more likely a result of the transition from a strong El Niño to a moderate la Niña condition during 2010. There was a similar decrease during the 1997/98 El Niño/La Niña transition.

18. Tenuc says:

I think it is likely we are entering a period where La Nina events outweigh El Nino for the next decade, like we experienced in the 70’s.

Changes in total solar activity level don’t have an immediate effect on Earth climate parameters, as different parts of the complex heat engine respond over different time periods, with the oceans, due to their enormous thermal capacity, showing a lag of ~8y and acting as ‘storage heaters’ for the global system. The current rapid temperature drops observed in several climate subsystems is an indication that climate is slowly shifting to a cooler regime.

Where we go from here depends on what happens to our variable star, the sun.

19. Ulric Lyons says:

@Roger Andrews says:
April 2, 2011 at 3:27 pm

“Maybe dust?”

Looks like the dust occurred at the depth of the cold, and because of the cold.

20. Roger Andrews says:

Tenuc

According to my projections global temperatures will remain more or less stable for the next three decades because the AMO and PDO will be in “cooling” modes, offsetting any increase that might be expected from CO2. However, if Tim Channon’s prediction of a decrease in future solar activity (forgotten which thread he made it on) turns out to be correct I would project that global temps will fall.

These projections are almost certainly wrong, but I don’t expect any comebacks because I won’t be around in three decades’ time. (Which raises the question of whether scientists should be allowed to publish catastrophic long-term AGW predictions when they know perfectly well that none of their contemporaries will be around to call them on it if the catastrophe never happens. My proposal would be to outlaw predictions that cover a period exceeding the life expectancy of the predictors. Given the comparatively advanced age of most climate scientists this would give them only ten or twenty years to play with, but if experience is any guide they’ll probably still blow it.)

Getting back to Ice Ages, there’s a paper by Wunsch (http://www.seas.harvard.edu/climate/pdf/wunsch_2004.pdf) which states: “Evidence cited to support the hypothesis that the 100 Ka glacial/interglacial cycles are controlled by the quasi-periodic insolation forcing is likely indistinguishable from chance.” I find it hard to accept that the +/- 100 Ka interglacial spikes in the Vostok record were caused by chance. Anyone else have the same problem?

21. Ulric Lyons says:

I think the 41kyr cycle is still present, and is modulating another cycle that came in just over 1 million years ago. Where they are best coinciding is not always at 100kyrs, there are many 1000`s years difference in time between major inter-glacial periods, if orbits were circular we would see much better regularity. Seeing where the recent 41kyr peaks were, could help in estimating how fast the drop off from this inter-glacial could be.

22. Tenuc says:

Here’s the latest NOAA/NESDIS Global SST Temperature Anomaly Map – looks pretty cold to me…

In regard to the Wunsch paper,Roger, I too am unconvinced that the ~100ky glaciation quasi-cycle is likely indistinguishable from chance – although perhaps non-linear spatio-temporal chaos has a part to play in varying the depth and timing of these events. I think Miles Mathis has a better handle on this.

Have you any ideas, Ulric, what could cause the 41ky cycle, bearing in mind Mile’s theory? I too think that the increase in dust is a caused by the drier ice age climate. However, it is possible that a deposited of dust over the ice sheets could help kick the climate back into the next inter-glacial???

23. Roger Andrews says:

Ulric and Tenuc:

Re Wunsch: His Figure 4 power spectrum clearly shows a Milankovitch solar cycle peak at around 100,000 years and another peak at 41,000 years corresponding to the period of the change in the earth’s axial tilt. So I guess I’m going to have to read the whole paper to figure out where he’s coming fr

Re dust: This is another chicken-and-egg problem. Did the cold cause the dust or did the dust cause the cold? There was probably a bit of both, but I think the dust certainly contributed to the cold even if it wasn’t the primary cause. And yes, it could have contributed to the recovery into interglacials. Dust on ice increases insolation and melting even though air temperatures may still be well below freezing.

24. Ulric Lyons says:

@Tenuc says:
April 11, 2011 at 5:23 pm
“Have you any ideas, Ulric, what could cause the 41ky cycle..”

It could be something to do with how the gas giant heliocentric alignments are orientated in relation to the galactic equator/poles.

The colder the winter, the bigger the dust storms are in the following spring.

25. Gray says:

Has anyone produced a spectrum of periods for the Vostok core.

26. Roger Andrews says:

Gray:

27. Tenuc says:

Roger Andrews says:
April 11, 2011 at 6:07 pm
“Re Wunsch: His Figure 4 power spectrum clearly shows a Milankovitch solar cycle peak at around 100,000 years and another peak at 41,000 years corresponding to the period of the change in the earth’s axial tilt. So I guess I’m going to have to read the whole paper to figure out where he’s coming from…”

So it looks like Wunsch agrees with Miles that the 100ky signal exists, but has insufficient energy change (thermal) to cause the ice ages. In view of this it appears that he then puts the extra glaciation it down to some sort of broadband stochastic natural process. Very strange!

Perhaps the real solution comes from the larger changes to the EM field caused by alignment to the galactic plane. As Ulric posits, perhaps the 41ky signal concerns the alignments of the gas giants, which so far Miles hasn’t considered?

28. Roger Andrews says:

Tenuc:

“So it looks like Wunsch agrees with Miles that the 100ky signal exists, but has insufficient energy change (thermal) to cause the ice ages.”

Changes in solar activity correlate to a greater or lesser extent with just about everything, yet they’re never large enough to have caused anything. Strange indeed.

29. Roger Andrews says:

OK, problem solved. Ice Ages are caused by the earth’s passage through galactic spiral arms (http://www.sciencebits.com/ice-ages).

30. tim212 says:

Interesting problems around the 100k cycle etc. I can confirm the 100k is not a doublet but it does not follow that this voids the basics.

Busy on something else.

31. Tenuc says:

Thanks for the link to Nir Shaviv’s paper of the cause of ice age epochs at the ~130my scale, which shows that CO2 has little influence. The changes in stellar density will also effect the EM charge field as well as GCR flux – looks like more work for Mathis!

Here’s a link to another interesting paper by Nir, The oceans as a calorimeter.

“…First, it means that the IPCC cannot ignore any more the fact that the sun has a large climatic effect on climate. Of course, there was plenty of evidence before, so I don’t expect this result to make any difference!

Second, given the consistency between the energy going into the oceans and the estimated forcing by the solar cycle synchronized cloud cover variations, it is unlikely that the solar forcing is not associated with the cloud cover variation.

Note that the most reasonable explanation to the cloud variations is that of the cosmic ray cloud link. By now there are many independent lines of evidence showing its existence (e.g., for a not so recent summary take a look here). That is, the cloud cover variations are controlled by an external lever, which itself is affected by solar activity…”

Good stuff… 😎

32. Roger Andrews says:

Tenuc:

Let me try out a new (at least I think it’s new) observationally-based theory on you, and on anyone else who might still be around.

Figure 9 of Alley et al. 2010 (http://www.uvm.edu/cosmolab/papers/Alley_2010_4052.pdf) compares the GISP2 ice core record from Greenland with the Byrd ice core record from Antarctica over the last 90,000 years, which is as far back as GISP2 goes. There are extended periods where Greenland and Antarctic temperatures move in phase and others where they move in antiphase. I got interested in this, so I downloaded the Byrd and GISP data and calculated correlation coefficients between the two over 10,000-year periods. Here’s what I got:

0-10,000 years BP, R= minus 0.28
10,000-20,000 BP, R= 0.60(?)
20,000-30,000 BP, R= 0.13
30,000-40,000 BP, R= 0.11
40,000-50,000 BP, R= minus 0.42
50,000-60,000 BP, R= minus 0.62
60,000-70,000 BP, R= 0.49
70,000-80,000 BP, R= 0.83
80,000-90,000 BP, R= 0.21

The records are indeed sometimes positively correlated and sometimes negatively correlated, and the positive-negative changes show signs of 40,000-50,000 year periodicity. (Note: the (?) after the 10-20,000 year R value is there because this is when the worldwide recovery from the last Ice Age into the current interglacial occurred, so a high positive R over this period is inevitable.)

The 40,000-50,000 year periodicity broadly matched the 41,000-year cycle in the earth’s axial tilt, so next I compared the R values with axial tilt angles (from http://www.museum.state.il.us/exhibits/ice_ages/tilt_graph.html🙂 Here’s what I got:

0-10,000 years BP, R= – 0.28, tilt = 23.9
10,000-20,000 BP, R= 0.60 (?), tilt = 23.6
20,000-30,000 BP, R= 0.13, tilt = 22.7
30,000-40,000 BP, R= 0.11, tilt = 23.0
40,000-50,000 BP, R= – 0.42, tilt = 24.1
50,000-60,000 BP, R= – 0.62, tilt = 23.9
60,000-70,000 BP, R= 0.49, tilt = 22.9
70,000-80,000 BP, R= 0.83, tilt = 22.8
80,000-90,000 BP, R= 0.21, tilt = 23.7

The two columns of numbers gives R= minus 0.68 for all data and minus 0.80 with the (?) 10-20,000 year interval discarded, and when you plot them on a graph the peaks and troughs line up. There’s an obvious relationship.

As to the physical mechanism, the negative Rs mean that Antarctica warms while Greenland cools (and vice versa) at high axial tilt angles, while both warm and cool together at low axial tilt angles. Presumably this can be related to insolation changes, but I haven’t looked into this yet.

Based on these results I conclude that the 41,000-year cycle in the Earth’s axial tilt generates changes in insolation that generate a 41,000-year dipolar climatic oscillation, and that this oscillation is what causes temperature trends in the Antarctic and Greenland (and presumably the rest of the Arctic) to change from an in-phase to an antiphase relationship during Ice Ages. I don’t think this tells us anything about Ice Ages, but it could well tell us something about the relationship between axial tilt, solar radiation and climate.

33. P.G. Sharrow says:

@Roger Andrews says:
April 13, 2011 at 12:51 am comments?

When I was young, about 50 years ago, it was known that both Earth and Mars polar ice caps waxed and wained, north to south and back, over 10s of thousands of years. I don’t remember the exact period that astronomers had worked out. Interesting that Mars has experienced “global warming” and “arctic” melt down along with the Earth during the last 40 years. The axial progression looks like the cause of one of the peroidics that you point out. pg

34. Tenuc says:

Thanks, Roger, for triggering some interesting thoughts.

Just so we’re singing from the same hymn sheet, here is my understanding about axial tilt and related things, please let me know if I have made any factual errors or wrong assumptions…

Earth’s axial tilt (obliquity) varies between 22.1 and 24.5 degrees, with a full cycle of 41,000y (from max to max).

Currently Earth’s obliquity is 23.4 deg, with the tilt decreasing.

Last maximum was reached ~10,700 BP, mean value occurred ~400 BP and the next minimum will be in ~11800.

Lower obliquity tends to produce conditions more favourable to glaciation.

As with orbital eccentricity, changes in axial tilt alter the extremeness of the seasons, with obliquity having most effect at the poles where ice ages begin.

Here is a graph showing Earth’s estimated obliquity & eccentricity +/-50,000y relative to current date…

As can be seen, the obliquity and eccentricity are tending to cancel each other out over the next ~18,000y, regarding severity of the seasons.

Any other assumptions we should be agreeing to before we move on would be most welcome.

35. @P.G. Sharrow says:
April 8, 2011 at 6:36 pm
Excellent analysis!

36. Roger Andrews says:

Tenuc

As far as I know your obliquity numbers are correct.

On the question of orbital eccentricity. As I understand it this changes TSI incident on the Earth by several percent either way and also changes the relative lengths of summer and winter in the NH and SH. So presumably it would also generate a hemispheric dipolar cycle, but over a period of 100,000 years, and it’s hard to pick a 100,000 year cycle out of a 90,000 year record, which is all I have to work with. (Wish I had more, but the GISP hole goes out of ice and into bedrock at 90,000 years, prompting the question of whether there even was any ice in Greenland during the last interglacial. At the very least the Greenland ice sheet was much smaller than it is now.)

Incidentally, http://www.jgiesen.de/kepler/eccentricity1.html allows you to calculate eccentricity up to 1,000,000 years backwards or forwards relative to the present.

Re your comment that “Lower obliquity tends to produce conditions more favourable to glaciation”. Greenland and Antarctic temperatures do tend to drop by about 1C during the change from high to low obliquity, but the dipolar effect of obliquity changes causes the Greenland-Antarctic temperature differential to vary by up to 5C. As I noted above, “the negative Rs mean that Antarctica warms while Greenland cools (and vice versa) at high (obliquity) while both warm and cool together at low (obliquity).” I think figuring out what causes this is the key issue.

Re your comment: “the obliquity and eccentricity are tending to cancel each other out over the next ~18,000y, regarding severity of the seasons.” Are eccentricity effects in fact large enough to cancel out obliquity effects? It seems to me that the dipole effect of a 2.4 degree change in axial inclination would exceed the dipole effect of a few days’ change in the length of the seasons between the hemispheres. Do you have any quantitative info on this?

Continuing my investigations, but ice core records are a bear to work with (thousands of readings, erratic reading intervals, no reading time correlation between different sites etc. etc.) Will maybe come up with more results later today.

37. Anything is possible says:

Roger :

I think you have to factor in the 23,000 year precession cycle as well to get the full picture.

In theory, the Arctic and Antarctic should be more “out of phase” when perihelion occurs at, or near, either solstice, whilst you would expect precession to have little effect when it occurs at or near the equinoxes. This effect should also be more pronounced when obliquity and eccentricity are both high.

It would be very interesting to see if this “theoretical effect” actually occurs in practice……

38. Tim Channon says:

Roger, there are ways to fix the irregular sampling but be warned the data is awful and not to be trusted. You could try http://www.gpsl.net and see if we can sort something out.

Does anyone here have the means to compute the earth movement on these timescales?

As I understand it the ice is moving and hole bottom does not mean there was no ice. There are also problem with ice movement messing up what is deep down, distorts and some say some melting occurs.
Something I have asked is, okay so we know where the ice is today, but where where was it when that snow fell? Even the altitude is likely to change.

39. Roger Andrews says:

Anything and Tim:

Thanks for your comments. However, I would now like to inject a wrinkle.

I still think the “dipole” theory has something to it, but it turns out that I can make most of the antiphase relationships go away by lagging the Greenland ice core record by 3,000 years relative to the Antarctic record. This also gives the best correlation between the two records (R=0.76 for 100-year averaged data). This lag doesn’t seem to be a result of age-dating errors because it’s fairly consistent over the 90,000-year length of the records.

The problem is explaining why Greenland temperatures should lead Antarctic temperatures by 3,000 years. Anyone have any ideas?

40. Tenuc says:

Thanks, Roger, for confirming that the data on my above post looks OK.

Roger Andrews says:
“Re your comment: “the obliquity and eccentricity are tending to cancel each other out over the next ~18,000y, regarding severity of the seasons.” Are eccentricity effects in fact large enough to cancel out obliquity effects? It seems to me that the dipole effect of a 2.4 degree change in axial inclination would exceed the dipole effect of a few days’ change in the length of the seasons between the hemispheres. Do you have any quantitative info on this?”

Like Miles, I don’t think the spacial changes are the cause of heavy glaciation, rather they lead to conditions where ice ages are possible. I think Mile’s may well be right in thinking that it is changes to the EM bombardment field which effects the solar system total energy level and that is the real driver of the ice ages.

The EM field could also explain the anti-phase relationships between NH and SH and the 3000y lag. I suspect this is ultimately caused by equal and opposite changes to EM field, which could have a number of weather regime effects. I suspect that long-term changes to the relative strengths of he polar vortices could be one potential candidate.

I’m not going to be around much for the next few weeks, but I will try and have a look in from time to time and I’ll make a quick comment if I get some other ideas.

41. Roger Andrews says:

Paper by Scafetta at http://arxiv.org/PS_cache/arxiv/pdf/1005/1005.4639v1.pdf , now being discussed over at J. Curry. Here’s the 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 oC and 0.25 oC, 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.”

Something here for everyone by the sound of it.

42. Carla says:

Roger Andrews says:
April 13, 2011 at 10:56 pm
..The problem is explaining why Greenland temperatures should lead Antarctic temperatures by 3,000 years. Anyone have any ideas?
~
A Breeze from the Stars

NASA spacecraft are monitoring an interstellar wind coming from the constellation Ophiuchus.

“..It’s a helium-rich breeze from the stars, flowing into the solar system from the direction of Ophiuchus. The sun’s gravity focuses the material into a cone and Earth passes through it during the first weeks of December. We’re inside the cone now..”

..The first signs of such a transformation could be the helium breeze thickening or shifting directions, heralding something new to come.

ACE has already detected changes. “We see strange gusts, ebbs and flows,” says Gloeckler. “We doubt these variations are interstellar.” Instead, the sun is probably responsible. The helium breeze must blow through the much denser solar wind, which can push the breeze around. Sunspots also affect the breeze. Ultraviolet radiation shining from sunspots ionizes the breeze and changes the way it appears to instruments like SWICS…””

http://science.nasa.gov/science-news/science-at-nasa/2004/17dec_heliumstream/

Just a quick note..article is older and SWICS data for this article is to 2004. Southern Hemisphere summer is during the transit of the helium focusing cone. So depending on how much time the southern hemisphere is bobbing below the solar ecliptic plane during its summer makes it different than the northern hemisphere summer. That didn’t come out quite right.. These days we know that there is more than just helium streaming through the system.. off to the store..

43. Roger Andrews says:

Carla:

There are two ways of interpreting the differences between the Greenland and Antarctic ice core data. First, glacial episodes in the Antarctic lag glacial episodes in Greenland by 3,000 years, with the cause unknown (at least to me). Second, the glacial episodes exhibit an in-phase/out-of-phase relationship that coincides broadly with the 41,000 yr cycle in the Earth’s obliquity. How might the “helium breeze” fit in here?

44. Roger Andrews says:

Jim Hansen still believes that ice ages are caused entirely by CO2. See Figure 4 in:

http://www.columbia.edu/~jeh1/mailings/2011/20110415_EnergyImbalancePaper.pdf

45. Carla says:

Roger Andrews says:
April 23, 2011 at 8:16 pm

How might the “helium breeze” fit in here?
~
You were looking for differences in the Northern and Southern hemispheres seasons.
The northern hemi has its summer in the nose direction of the heliospheres orbit. Whilst the Southern Hemisphere has its summer with the “additional” helium to its summer.

46. Carla says:

continued..Whilst the Southern Hemisphere has its summer with the “additional” helium to its summer. Whilst on the backside (tailside) of the heliosphere.

47. P.G. Sharrow says:

Increased glaciation is caused by increased snow not by increased cold. 😉 pg

48. Roger Andrews says:

P.G.

You’re right. We tend to over-fixate on temperatures. There’s abundant evidence just from the last century to show that precipitation is usually the major player. One example is the European Alps, where glacier retreat is effectively uncorrelated with temperature but highly correlated with the AMO, which is what controls precipitation. Another is Kilimanjaro, where the ice cap has been shrinking since about 1880 because of decreased precipitation even though temperatures on the summit never rise above freezing.

Problem is that we don’t have any long-term precipitation records to work with. However, I seem to recollect that the ice core records do have some data on ice accumulation rates. I’ll take a look at this tomorrow.

49. P.G. Sharrow says:

Roger Andrews says:
April 24, 2011 at 3:00 am

Very true Roger, temperature is a piss poor proxy for energy in the mix of atmospheric gasses. Water carries nearly all the energy in the mix, and with little temperature change.

It is interesting how a strong sun inflates the atmosphere, and that thickened insulation slows energy loss, the real greenhouse covering, and a quiet sun reduces the thickness of our blanket. As the atmosphere loses increase the “warm” ocean dumps heat energy as water vapor to maintain the energy level in the atmosphere over the oceans. The atmosphere over the land loses energy to space as the water vapor freezes out to maintain temperature. Result, little temperature change and a lot more snow. Albedo changes over land causes slower warm up in spring with no change in spring ocean warming. Result, later and heaver snows.

When the oceans are much lowered and a bit cooler the evaporation slows to the point of equaliberation of energy flows and the atmosphere dries out. A dry atmosphere losses energy faster and stays cooler. A dry atmosphere results in greater dust storms that result in dust accumulating on top of the snow, darkening it to increase the warming over land and begin the melt off. Muskeg of the high north is just dirt over ice, the remnents of the iceage ice cap with grass and poor trees growing on it.

People think that the Iceage ice cap over the North hemisphere was this 5,000 to 10,000 foot thick block of ice that went away in a few thousand years. In reality it would have appeared to be grass and tree covered highlands that shrank as the sub soils and ice warmed and leaked water. Movement glaciation would have taken place as the tall “front” began melting away. The deep interior ice would have long before sublimated away in the cold desert phase. So when the “melt off” occured, it happened with a bang! as the albedo of the north dropped quickly.

“Warm” oceans cause Iceages and “cold” oceans end them! Now who could believe possibly this? 😎 pg

50. Roger Andrews says:

P.G.

“Warm” oceans cause Ice ages and “cold” oceans end them!”

On April 5 I commented that maybe “….. ice ages begin when the Arctic Ocean becomes ice-free, which results in increased winter snowfall over Siberia and Northern Canada, and end when the Arctic Ocean freezes over again, which chops off the supply of moisture.” Same thing, I think.

However, this process can occur only in the NH because we have no Arctic Ocean equivalent in the SH. So if the theory is correct we should get ice ages in the NH and not in the SH.

We know from physical evidence that we have had four glacial advances and retreats over the last 400,000 years in the NH. Moreover, the GISP2 core goes out of ice into bedrock at 80,000 years, indicating that there was little or no ice in Greenland during the last interglacial maximum. So yes, we get ice ages in the NH.

In Antarctica, however, the EPICA core has drilled 800,000 years of uninterrupted ice (and the Vostok core 400,000 years). In other words, we haven’t had four ice ages in Antarctica, just one continuous ice age.

The practical impact is that NH ice extent changes by a factor of ten or more between glacials and interglacials while SH ice extent changes by only a few tens of percent. See:

So the albedo changes that amplify glaciation and deglaciation occur almost entirely in the NH too.

51. P.G. Sharrow says:

Roger Andrews says:
April 25, 2011 at 4:27 pm;

You’ve got it!

High warm oceans with solar trip, Ice age starts up. Loss of energy as well as water sets up for melt off. Just takes time. The Arctic regions land surrounding sea and the Antarctic land surrounded by seas causes the different behavior. Albedo changes in the north causes overall losses and gains in total energy for the earth. “Ice Age” followed by warm up “Inter Glacial”. The energy received from the sun would change very little over long term, just short term changes, normal cycles. Ice Ages are as much caused by the lay out of oceans and land masses and the physics of water as any thing else.

The sun and the energy flow to the earth changes very little over the long term. most of the energy goes into the oceans that in turn try to warm the atmosphere. The land warms in the sun and cools in the shade. And WATER is THE green house gas.

Now someone needs to write a book to lay out the whole thing and educate educated people. 😎 Maybe a waste of time. pg

52. This paper will attempt to reconcile various issues within the current academic debate over the climate of the earth. I intend to show that the temperature of the earth is a function of various disparate parameters.

The earth in its simplest form is a black body and it radiates energy as a function of its average temperature.
This average temperature is a function of incident radiation, and the orbital dynamics of the earth-sun system and planetary Albedo and can be given by the following function.

The known average temperature of the atmosphere varies between + 10 degC and + 40 degC of this theoretical figure
The principle reason for this anomaly is the greenhouse effect.
CO2, CH4, and H2O are the principle greenhouse and icehouse components.
When the level of greenhouse gases in the atmosphere fall below threshold values then the action of H2O liquid and solid become the principle climatic variables.
With reference to my previous submission on Milankovitch cycles formulated in the graph below, which shows the records of an unrepeatable empirical experiment contained in the geological record and found in the article. http://en.wikipedia.org/wiki/Marine_isotope_stage

I will attempt to quantify the temperature record in respect to rising albedo and falling CO2 levels.

Milankovitch theory shows that approximate 26 kyr Insolation cycles lead to a corresponding 26 kyr cycle of average global temperatures. From the above graph it can be seen that when the mean temperature is above 0 degC Vostok equivalent the cyclical variation in temperature is less than 2 degC peak-peak. For the duration of the temperature record CO2 levels have been falling due to net carbon sequestration over the 5.5 Myr recording period, this fall is of the order 400 ppm at 5.5 Myr to 280 ppm at the end of the last interglacial, with a theoretical slope of 22ppm per Myr. This would lead to a theoretical CO2 level of 335 ppm CO2 when the cycles changed to a 41 kyr periodicity and 305 ppm when the periodicity changed to 100 kyr.

The question I have been wrestling with is why.

It is an undisputed fact that we have recently gone through a prolonged period of ice ages. My contention is that the increase in Albedo is responsible for the increase in amplitude of the temperature variation, and the change in periodicity.

Changing the Albedo factor in the blackbody function given above from 30% to 32% gives additional cooling of up to 2 degC which would be sufficient to double the cyclical Milankovitch temperature variation to 4 degC peak-peak. Also internal variations of amplitude between Insolation lobes may be responsible for the change in periodicity. This periodicity is apparently equal to 1.5 Milankovitch cycles.

A further change in Albedo to 35% increases the blackbody cooling to 5 degC this would be sufficient to treble the cyclical Milankovitch variation to up to 7 degC peak-peak. As above this then appears to lead to a further change in periodicity.

It is probable that some additional cooling due to falling CO2 levels is also within the record but I intend to show that this cooling is of a lower order.

I also intend to show that the atmospheric CO2 level quoted above, 400ppm, is directly related to the average temperature of 1 degC +/- 1deg which is relevant to the current Global Warming debate.

The following is in reference to the ice core data below from the quoted article

http://en.wikipedia.org/wiki/Vostok_Station

My interpretation of this graph is that after increasing Albedo has triggered a glacial, the subsequent Milankovitch cycle variations revert to a lower amplitude of approximately 4 degC peak -peak which appears to be composed of the 2 degC Insolation component and a 2 degC Cooling induced CO2 modulation, until the abrupt glacial termination when the CO2 levels return to 280 ppm approximately.

If my estimate of the CO2 levels are correct, current CO2 levels of 400ppm should be interpreted as a future 2 decC peak-peak variation during the next positive Milankovitch cycle, i.e. from the current level of 0 degC to +2 degC, with a time scale of 11 kyrs.

Mike Davies

53. Roger Andrews says:

P.G.

I did a Google search for “ice age” and got 25 million hits. I did one for “interglacial period” and got only 200,000. Clearly everyone is trying to explain what causes ice ages. Nobody cares about interglacials.

And this is entirely the wrong way of approaching the problem. Take a look at the cartoon at http://c3headlines.typepad.com/.a/6a010536b58035970c0128766b00e7970c-800wi. It shows that for well over 90% of the last 400,000 years the Earth has been to a greater or lesser extent in “ice age” conditions. In other words, ice ages are the climatic norm. We don’t have to explain them. They’re the Earth’s natural condition, at least at this point in its history.

What we DO have to explain is why every 100,000 years or so the ice ages are interrupted by a brief (comparatively speaking) interglacial spike. These interglacial spikes are the climatic anomaly, not the intervening ice ages.

Up to this point we and everyone else have been concentrating on what causes ice sheets to grow. What we should be concentrating on is what causes them to shrink, because this is what initiates the interglacial cycle.

So what we need to do is shut our eyes, visualize an ice-bound NH, and think about what kind of climatic event or combination of events might cause the ice suddenly to start retreating and to continue to retreat for the next 10,000 years. The initiation of the retreat is so abrupt that there has to be some kind of tipping-point mechanism involved.

54. Anything is possible says:

Roger Andrews says:
April 26, 2011 at 4:13 pm

“So what we need to do is shut our eyes, visualize an ice-bound NH, and think about what kind of climatic event or combination of events might cause the ice suddenly to start retreating and to continue to retreat for the next 10,000 years. The initiation of the retreat is so abrupt that there has to be some kind of tipping-point mechanism involved.”

_______________________________________________________

Could the answer be that the ice simply “over-extends” itself?

After accumulating for 80-90,000 years, perhaps the only places left for ice to expand are into areas where, even at the peak of an inter-glacial, temperatures are still too warm to sustain a permanent ice and snow cover. Could this be enough to initiate the melting process, and send the whole process into reverse?

Given that we are focusing on internal, rather than external forces, driving glacial and inter-glacial cycles, I’d like to throw geological processes – specifically glacial-isostatic rebound into the mix as having an influence on the length of the inter-glacials :

When land is covered by thick ice, the weight of the ice causes crustal depression. Remove the ice, and the land can be up to 2-300m LOWER than it was before the ice started accumulating. Two to three hundred metres lower also equates, everything else being equal, to 1-2 degrees WARMER.

As long as the land remains ice-free, the process of glacial-isostatic rebound proceeds – and we can see this in action today, especially around Hudson Bay and the Baltic Sea, with the land uplifting at a rate of up to 1 cm per year. Given that these are the very areas that we would expect to be covered in ice first upon the commencement of the next ice age, could it be that the increased elevation, and resultant cooling in temperature, be the “tipping point” you are looking for?

55. Anything is possible says:

Further to my theory, and looking at the bigger picture, ice sheets are very powerful erosional agents. With each successive glaciation, vast quantities of material will be removed from the affected land areas, ultimately leaving the land lower, and hence warmer.

Does this means that, over the course of geological time, this lowering and “warming”) of the land will make the affected areas ( Northern Canada and Fenno-Scandanavia, in particular) less and less vulnerable to future glaciations? Will, over the course of the next million years, inter-glacial events become longer at the expense of glacial periods? Will NH glaciations eventually become a thing of the past?

Fascinating (if highly-speculative), stuff……..

56. P.G. Sharrow says:

Roger Andrews says:
April 26, 2011 at 4:13 pm “see cartoon”

Yes, very interesting, get rid of the color and I see about 22,000 year cycle of warm and cold, very consistent. Looks like Vostok, antarctica is going to get real cold, very soon. The last 8,000 years have been extraordinary warm and not normal. 6 to 8,000 years ago the sea levels were at their highest as temperatures were at their highest. Does sea level lead or lag temperature? Water is the working fluid of this heat engine. pg

57. Roger Andrews says:

Tim:

I’ve just about given up trying to do anything serious with the ice core records. The irregular sampling was bad enough, but now I’m beginning to think there are problems with the dating too.

One of the reasons I think this is that according to the Vostok and Epica ice core records the period between interglacials is getting longer. The interglacial peaks in the Epica record, for example, occur at 407000, 334000, 242000 and 129000 years BP, giving periods of 73000, 92000, 113000 and 129000 years. The average is 102,000 years, which is within a whisker of your 100,000 year spectral peak.

The question is whether these periodicity variations are real. I’m not sure they are. One possibility is that interglacials actually occur about once every 120,000 years and that the deep ice is a lot older than we think it is.

58. Roger Andrews says:

Anything is possible:

I read your theory and thought, no, doesn’t work. Glacial isostatic depression/rebound and erosion are symptoms of glaciation and deglaciation, not causes.

But then a thought occurred to me.

Where did the NH ice sheets originate? In the middle of what is now Hudson Bay and in the middle of what is now the Baltic Sea, both of which were formed by ice.

And ice sheets don’t form and grow in the middle of the sea.

But what happens when Hudson Bay and the Baltic become dry land again, which at current rates of rebound should occur at some time in the next five or ten thousand years? Do ice sheets start growing there again? We can at least assume that there must be something climatically special about these two areas because otherwise the ice sheets wouldn’t have started to form there in the first place.

59. Tim Channon says:

Very interesting idea.

They will get colder and could be large enough to nucleate, so whilst it seems intuitively improbable, the Baltic without thermally moderating water might start a major ice cap.

60. Tim Channon says:

Dodgy ice cores?

” Monnin et al. 2004 High Res. (0-22KYrBP) CO2 Data and Taylor Dome CO2-synchronization Time Scale”

No-one has ever had the nerve to explain the following other then denial or other faffing.

Some time ago I noticed a problem. It seems the data has perfect spring law.

I deleted some points (outside of the region), added a fake point at zero and that is real data points. The exact square law match is done by the plot software.

The law for compacting snow seems to be x^1.14 or similar. In cores there tends to a discontinuity when ice forms.

A quick search, here be the data

A quick reproduction on the whole data, r2=0.99 for ^2

Now read the text in the dataset.

61. P.G. Sharrow says:

The use of the conditions of the present era as the base line for ice age / interglacial may be confusing as to cause and effect. We have cyclic changes that are caused by solar effects and we have wax and wain caused by sea level changes and dust coverings. Who knows how many other things push and pull the peaks and valleys of ice accumulation. pg

62. Tim Channon says:

Looked at Epica, took very little time, all working a charm.

If you want an untangled dataset can do.
Spectra suggests it isn’t very good but is much the same as vostok. Main difference is the 100k is split, 64k is now large.

Putting stuff up is a pain, takes much longer.

I have something far more interesting mostly prepared.
Too late to do it now.

63. Tim Channon says:

“The vagarities of moonshine and ice”
Authors: Wax and Wayne

64. Ulric Lyons says:

Roger Andrews says:
April 26, 2011 at 11:09 pm.

65. Roger Andrews says:

Tim:

I read through the Taylor Dome stuff. It doesn’t exactly fill one with confidence.

The Vostok-Epica peaks and troughs are also displaced up to 20,000 years relative to each other (in both directions) before about 150,000 years BP. This looks like another age dating problem.

An untangled data set would be nice, but I don’t want to interrupt the far more interesting stuff you are doing. Can’t wait to hear what it is.

Do you know of a long-term dust data set for Greenland ice core? I can’t find one.

66. Tim Channon says:

Roger, quick fix, have added a copy of an XLS to the above post. Probably good enough data in there.

67. Roger Andrews says:

Thanks Tim. I’ll look it when I get back from dinner

68. bill says:

Continental placement reason for (and increasing time span of) glaciations.

http://www.scotese.com

NH glaciation builds from SOUTH to NORTH except in places where land forms extend poleward – example ; Canada’s Arctic Islands, Greenland, Western Russia.

Tip point is main ocean access to arctic ocean. (Began in 1980’s)

Time span of abrupt change – – DECADE to CENTURY

Greenland melt probably occurs in conjunction with glaciation building elsewhere – –

don’t expect sea level rise in conjunction with Greenland melt.

bill

69. Tim Channon says:

This might at the moment seem off topic. See if you can figure out where it is leading.

http://daedalearth.wordpress.com/2011/04/30/how-polar-ice-is-modulated-by-the-sun/

70. Roger Andrews says:

This thread seems to be dying of old age, so let me see if I can get it going again, or if not at least end it with a bang.

I have concluded that we’ve got everything backwards. We think ice ages are caused by climate change, but it’s actually the other way round. Climate change is caused by ice ages. And ice ages are controlled by the cyclic behavior of the NH ice sheets.

First, three governing assumptions:

1. For at least 400,000 of the last 500,000 years the Earth has been in an ice age condition. In other words, ice ages are the norm. We don’t have to explain them. What we do have to explain are the interglacial periods. These, not the ice ages, are the anomalies.

2. Interglacials occur only in the NH, where ice sheet extent ranges from maybe as much as 30 million sq km during glacial maxima down to a small fraction of that during interglacials. They don’t occur in the SH. Antarctica has been ice-bound for millions of years.

3. The problem of explaining what causes ice ages therefore comes down to explaining what causes NH interglacials.

Now the explanation, step by step:

Step 1: The NH exits an interglacial period and the NH ice sheets begin to advance again. (Note, we don’t have to explain why they advance. Ice ages are the norm. The Earth is simply returning to its natural climatic – or if you prefer, “balanced” – state.)

Step 2: The NH ice sheets continue to advance for tens of thousands of years. But eventually a point is reached where they become top-heavy, and then they begin to behave like surge glaciers, calving large quantities of ice into the sea once every five or ten thousand years. These “Heinrich Events” (HEs) are identified from ice-borne detritus in sea bed cores, and they are uncorrelated with temperature, CO2, dust, solar activity or any other climatic variable. They’re purely a result of ice sheet dynamics.

Step 3: HEs are usually not large enough to upset the balance between ice sheet stability and albedo, but eventually we get one that is. The last HE, which occurred about 15,000 years ago, was one. It calved off an enormous amount of ice at the margins of the ice sheets (maybe as much as 10,000 sq km) and the ice that was left couldn’t fill the hole fast enough to offset the warming impacts of the albedo change. So the climate warmed and the ice sheets continued to retreat, and now we are back in an interglacial.

Step 4: The interglacial ends. How? Straight answer, I don’t know, but the trigger is again probably physical rather than climatic. So for the time being I’m going to stick with the theory that the NH ice sheets start growing again when the Arctic Ocean becomes ice-free and/or when the Northern Baltic and Hudson Bay become dry land.

And where do solar cycles fit in? Well, they don’t. Sorry about that.

71. Tim Channon says:

With no header changes few people will spot any activity.

1. Yes.
2.
3. Explaining any of it would do.

If you looked at the stuff I posted elsewhere yesterday, at the end I asked if anyone could guess where things are leading.

I’ll pop something up later. Yes it goes to ice.

72. Roger Andrews says:

Tim:

I think you’re trying to make the case that Milankovitch cycles cause ice ages and interglacials, but I’m not sure. Could you clarify?

73. Tim Channon says:

Sorry if my style is more that of pointing things out but without drawing anything definite. Leave that for the reader without too much leading.

I am indicating that a fairly benign looking variation _does_ produce a highly asymmetric modulation of ice on earth.

I also point out that low grade data for historic temperature related could be considered to have a similar look. The supposed mystery of sharp looking warm periods might be a dual of sharp looking warm periods of annual polar ice, where the stimulation does _not_ contain any sharp term, is the consequence of a bipolar process driving a unipolar process.

Therefore a similar cause is on the books.

Milankovitch , don’t know, something of that kind, yes.

Also, I point out that having the top knocked off a geometric shape (flattening) given we are dealing with a sphere with land/ocean seems rather likely. Note that glaciers at sea level in the tropics are awful rare.

From that is suggested a variation in temperature range between poles and equator.

Given the earth orbit kinetic energy cannot change; the shape of the earth orbit is supposed (not seen any evidence) to change markedly on a 10 to 100 ky scale, this might change annual insolence variation markedly. I don’t see how that could cause massive polar modulation on a long timescale.

The tilt of the earth axis does change but this too is not supposed to be enough.

A lot of don’t know in the above. That is why i want to calculate and model this stuff for myself.

EPICA is a worry. Basically it says there is something radically strange, with assertions that there has been massive change. On the other hand I personally suspect the data is terrible and wrong.

As a further matter, which might be news, I have evidence confirming Wolff and Patrone’s assertion of a barycentre solar effect. If there really is a solar effect from the planetary system this puts solar modulation in the frame as well from the same earth orbit change.

74. Tim Channon says:

A question: –

At the moment maximum sea ice occurs when earth insolence is at maximum and minimum when the sun is at minimum.

The opposite phase condition will occur under opposite orbital conditions.
Maximum ice at minimum solar, minimum ice at minimum solar.
Antarctica will be affected also.

The TSI variation is about 10W, much less than 1% (quick calc, 0.68%). I make that a 2K change in earth temperature _if it was a steady state change_ which it is not.

I’d be surprised if work on this problem, what happens, has not been done by various individuals.

Anyone know of references?

75. Roger Andrews says:

http://www.ncdc.noaa.gov/paleo/pubs/huybers2006b/huybers2006b.html

Discusses solar-ice relationships and also contains summer insolation time series for different latitudes.

76. Roger Andrews says:

Two data sets from DSDP site 607 sea bed core (North Atlantic) at:

s607/ch82isocib.txt

They contain 018 data going back 3 million years. Comparing them with Vostok & Epica gives interesting results.

77. Roger Andrews says:

The above links don’t work for some reason. Try

78. Tim Channon says:

Thanks. The full letter itself is available. Seems vague.

I have a suspicion I am being naive in assuming there is reasonably accurate knowledge of paleo earth orbit data.

Never mind, lets go with what has turned up and see where that leads.

79. Tim Channon says:

Try this version
http://www.moraymo.us/climate_archives.php#2006_Science

80. Tim Channon says:

Here is an interesting paper, probably largely ignored by the statistics based majority.

Sleuth work which seems to extract the missing 400ky strong insolation as a major player.

Earth’s orbital eccentricity and the rhythm of the Pleistocene ice
ages: the concealed pacemaker
J.A. Rial*
http://www.geolab.unc.edu/faculty/rial/GPCiceages.pdf

81. Tim Channon says:

Neat. 🙂
I’ve found some actual figures. The surprise was agreement with what I have been measuring and solves one mystery, something without mention anywhere else.
The bad news is the extreme complexity, which I had assumed was my doing something wrong.
This gives me a little confidence something good enough can be done, if unlikely to get a useful result.

Not sure this will add any general insight.
http://www.eos.ubc.ca/~mjelline/453website/eosc453/E_prints/AnnRev.28.1.419.pdf

82. Tim Channon says:

Found one candidate for long earth parameters. In the remote chance anyone else wants to look. Typical science stuff, look under sun for earth data.
ftp://ftp.imcce.fr/pub/ephem/sun/la93/

In theory I can handle Fortran but portability can be a headache.
The source looks sane, if with a mix of English and French comments.
Need to try and figure out whether it does what I want.