## The Virial Theorem

I had another brief Twitter discussion with Ned Nikolov, whose paper I discussed in this post. Ned seems to think that there is no atmospheric greenhouse effect and that the enhanced surface temperature is due to atmospheric pressure somehow enhancing the energy provided by the Sun. Well, this is wrong, and I thought I would try to illustrate why by explaining something that I find interesting.

I’m currently teaching our core Astrophysics course. A big part of what I’m doing in this course is deriving the equations of stellar structure, which includes the equation of hydrostatic equilibrium. A star, like the Sun, will settle into a state of hydrostatic equilibrium, in which the inward gravitational force is balanced by an outward pressure force. Any self-gravitating system (by which I mean something for which its own gravity is important) in a state of hydrostatic equilibrium satisfies something called the Virial Theorem. This is essentially that the gravitational potential energy of the system is about the same as its thermal, or kinetic, energy (in fact, it is that the magnitude of the gravitational potential energy is twice the thermal/kinetic energy).

We know the mass, $M$, and radius, $R$, of the Sun and – hence – can estimate its gravitational potential energy; it will be of order $GM^2/R$. From the Virial Theorem we also then know the total thermal energy of the Sun. We also know the Sun’s luminosity (how much energy it is losing per second). This means that we can estimate how long it would live if it was simply radiating its thermal energy into space. The answer is that it would live for only a few tens of millions of years.

The idea that the Sun might simply be radiating thermal energy into space was first suggested by Kelvin and Helmholtz in the 19th century. However, at that time it was also known that the Earth (and, hence, the Sun) was probably billions of years old, rather than only a few tens of millions of years old. This meant that the Sun’s energy source could not simply be gravitational potential energy being converted into thermal energy as it slowly contracted, because that would imply a much, much younger Sun than geological, and fossil, evidence suggested.

This paradox was resolved with the discovery of nuclear reactions, specifically nuclear fusion. In the core of the Sun, protons combine to form Helium, and this process releases energy (Helium has a lower mass than the total mass of 4 protons, and this mass deficit is released as energy – $E = mc^2$). It is this that allows the Sun to remain in a roughly steady state for billions of years, rather than for only a few tens of millions of years.

The above isn’t strictly relevant to the Earth’s atmosphere, because the gravity of the atmosphere itself isn’t all that important; the Earth’s atmosphere is in hydrostatic equilibrium because the outward pressure force is balancing the gravitational force from the central, rocky planet. It is, however, relevant for big gas giant planets, like Jupiter and Saturn. However, we can still consider much of the same basic physics.

If the Earth’s atmospheric pressure is to contribute to the enhanced surface temperature, then that would mean that the atmosphere would need to continually provide energy to the surface. It could only do this through the conversion of gravitational potential energy to thermal energy. This would then require the continual contraction of the Earth’s atmosphere. However, we can work out how much energy is available in the Earth’s atmosphere and there is far, far too little to explain the enhanced surface temperature.

As many already know, the enhanced surface temperature is due to radiatively active gases in the atmosphere that act to reduce the outgoing energy flux, causing the surface to warm until the amount of energy we’re losing into space matches the amount we’re receiving from the Sun. It is not simply a consequence of atmospheric pressure. Those who argue that it is due to atmospheric compression are essentially failing to understand something that was well understood by physicists in the 19th century.

Update:
As pointed out in this comment I’ve probably somewhat over-stated the discrepancy, in the 19th century, between geological and fossil evidence for the Earth’s age, and how long the Sun could live if it were simply radiating away thermal energy (10s of millions of years). At the time of Kelvin the estimated age of the Earth was probably more like 100s of millions of years, rather than billions. Today, however, we would estimate the Earth to be about 4.56 billion years old.

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### 128 Responses to The Virial Theorem

1. The reason I said It is not simply a consequence of atmospheric pressure is because atmospheric pressure does impact the greenhouse effect. This is not because the pressure somehow heats the surface, but because atmospheric pressure influences the overall width of the spectral lines due to the radiatively active gases and hence influences the absorption of outgoing radiation.

2. crackers345 says:

Nice reasoning. Let me guess: this didn’t convince Ned Nikolov in the least.

3. Let me guess: this didn’t convince Ned Nikolov in the least.

Right first time. I wasn’t really expecting it to, though.

4. I applied the Virial theorem at one stage in a post I did at my old blog:

“Derive the adiabatic index and lapse rate for both planets, Venus and Earth, using only the planetary gravitational constant, the molar composition of atmospheric constituents, and any laws of physics …” http://theoilconundrum.blogspot.com/2013/05/the-homework-problem-to-end-all.html

I don’t know if this is a correct derivation, partly because you are essentially solving for a single physical constant, whether it is the lapse rate or adiabatic index. Yet, there are too many parameters that can be manipulated to arrive at a match to the observations. I haven’t really pursued this because of this validation issue. Plus, a planet doesn’t have a single value but it changes according to latitude.

Nikolov is not rational on this topic and probably any other topic.

5. ATTP writes:”Those who argue that it is due to atmospheric compression are essentially failing to understand something that was well understood by physicists in the 19th century.

Color me surprised. /sarc

It seems pseudoskeptics ignore every 18th & 19th century scientist; How often in Climateball have we brought forward the names Fourier, Tyndall, Arrhenius etc., etc., and tried to explain that XYZ has been known like since forever 🙂

6. “It is, however, relevant for big gas giant planets, like Jupiter and Saturn. However, we can still consider much of the same basic physics.”

This is a good point as the radial continuity of a gas giant makes it easier to reason about (which is what I solved for in my previous comment link).

To me the big mystery is why a gas-giant like Saturn with it’s spiral density waves is explainable by the influence of it’s moons:

“The density wave is generated by the gravitational pull of Saturn’s moon Janus.”
September 11, 2017 https://www.space.com/38114-weird-waves-saturn-rings-cassini-photo.html

Yet the same thing could apply to the dynamics of the equivalent but invisible Earth ring, that is the QBO.

“This temperature and zonal wind structure resembles those of Earth’s quasi-biennial oscillation (QBO) and Jupiter’s quasiquadrennial oscillation (QQO), in which temperature anomalies and eastward/westward winds alternate in altitude”
Fouchet, T., et al. “An equatorial oscillation in Saturn’s middle atmosphere.” Nature 453.7192 (2008): 200.

But no one has made the connection of the moon to QBO. Is that only because the Earth is not a gas giant? I find that hard to believe.

7. izen says:

If pressure determined temperature, why are the deep oceans colder than the surface ?

@-geoweb

Obviously there is a lot of energy in tidal forces. That is shown by the raising and lowering of Earths oceans and the heating of Io.

The amount of energy available from the Lunar tides changing gravitational potential energy is beyond my abilities to calculate. But I wonder how it compares with the amount of extra energy retained at the surface from raised atmospheric CO2. Tidal forces can be invoked as an energy input, but that they are of any significance, given the lack of any apparent warming of the Earth’s Moon, I find hard to believe.

8. Paul,

I applied the Virial theorem at one stage in a post I did at my old blog:

The Virial Theorem doesn’t apply to Earth’s atmosphere because the dominant gravitational influence is from the solid planet, not from the atmosphere itself.

9. izen,

If pressure determined temperature, why are the deep oceans colder than the surface ?

Good point.

10. Phil says:

atmospheric pressure influences the overall width of the spectral lines due to the radiatively active gases and hence influences the absorption of outgoing radiation.

It is conceivable (no stronger than that) that there is another effect that means atmospheric pressure plays a role in the greenhouse effect. According to my Ph.D. thesis, this was suggested by T.R. Dyke at an RSC (Faraday division) meeting in December 1984. The theory goes something like this …

It has been known since the 1960’s that IR absorption occurs not only for individual molecules, but for “paired” molecules or complexes that are joined by weak intermolecular forces, such as hydrogen bonds. See this paper (earlier papers in this series would have been more relevant, but I was unable to find them online).

This pairing up of molecules has two consequences:
1. Five translational and rotational degrees of freedom are lost, and these become vibrations, which typically occur in the far infra-red (i.e. co-incident with “earth-light”). There is a stretch, which is essentially the two molecules pulling themselves away from each other, and four bends which may be double degenerate.
2. The existing vibrations of the individual molecules are modified in two ways:
a. The actual “fundamental” (centre) of the vibration changes.
b. The rotational fine-structure of the vibration band changes, becoming more dense due to the larger moment of inertia of the complex.
This two effect will go some way to “fill the gaps” in the ro-vibrational absorption of the individual molecule.

In Earth’s atmosphere, I imagine the most abundant complex would be CO2…H2O, looking something like this: O=C=O…H-O-H where … is the hydrogen bond and the H-O-H angle is bent.
The (H2O)2 dimer may also play a role:
H
\
O … H-O-H
/
H
This being a sort of “first stage” in the condensation of gaseous water into liquid.

Formation of such intermolecular complexes would be favoured by higher pressures (and also lower temperatures)

Now, I have no idea whether T.R. Dyke’s suggestion of a role for complexes in the greenhouse effect has been investigated in any detail, or whether it remains a theoretical possibility or whether its been determined to be too insignificant – perhaps the concentrations of such species are far too low for them to play a significant role in the GHE. It was certainly a fruitful source of laboratory investigation in 1980’s and beyond – D.J Millen, A.C Legon, J.W. Bevan are significant people at the UCL lab, David Buckingham (at Cambridge) did theoretical calculations and there must be many more.

11. Phil,
Interesting, thanks. That all seems plausible, but I don’t have any idea if it plays much of a role in the atmospheric greenhouse effect.

12. Small water clusters are still interesting theoretically
https://arxiv.org/ftp/arxiv/papers/1604/1604.06854.pdf

13. verytallguy says:

IIRC the only relatively common molecules that exhibit significant gas phase association are acetic acid (dimers) and hydrogen fluoride (hexamers and others). Hopefully we will never see appreciable concentrations of either in the atmosphere!

These gas phase associations decline with pressure, so where it matters most (top of atmosphere) you can expect them to be present at *very* low concentrations, even should they exist at surface pressures.

So unless these mooted complexes had extraordinarily high IR absorbtivity, it would be surprising in the extreme should they influence the greenhouse effect.

14. Eli Rabett says:

Phil that is a somewhat confused tale about collisional broadening which “fills in” the spaces between the rotational lines, however it is also completely wrong to say that there is no absorption by isolated molecules and that O2 and N2 do not collisionally broaden the CO2

15. Ed Davies says:

Izen: “If pressure determined temperature, why are the deep oceans colder than the surface ?”

If pressure determined temperature, why is the bottom of the stratosphere colder than the top?

16. Eli,
I didn’t think Phil was trying to explain pressure broadening. I think was simply highlighting a suggestion that complex molecular structures could also influence the greenhouse effect.

17. Andrew J Dodds says:

I’d guess that if these associations had a significant role, they would appear in measurements of the IR spectra of the gasses. Interesting concept though.

18. Eli Rabett says:

Water dimers do, but not the things phil was writing about.

19. angech says:

Izen: “If pressure determined temperature, why are the deep oceans colder than the surface ?”

Because they are further away from the sun, less heat. In actual fact without increasing pressure the deep oceans should be frozen ice. The increasing pressure/compression keeps the water from freezing when it should. If you go below the ocean the temperature of the crust rises with increasing pressure.

From Physics stack, arguable points, not my words.
“The actual relation is “increasing the pressure of an ideal gas while volume remains constant increases the temperature of the gas”. Temperature only increases as you put more stuff in the same volume. That is, it isn’t pressure that increases temperature, it’s compression. If you compress a volume of air, the temperature will rise, and if you release it again, the temperature will drop again.”

“Ned seems to think that there is no atmospheric greenhouse effect and that the enhanced surface temperature is due to atmospheric pressure somehow enhancing the energy provided by the Sun. Well, this is wrong,”

The GHG effect is there and explains the surface temperature.
The atmospheric pressure is determined by the composition of the atmosphere and the gravity of the earth. There would be equations. the equations go both ways so if one wants to draw a long bow one could certainly tie a pressure to a surface temp given the known atmospheric composition and gravity. Saying the pressure is the cause of the temperature when it is an effect itself is the problem.
With the GHG effect one can certainly say that it is there and is the cause of the enhanced ST given the composition and gravity present.

20. Willard says:

How do blankets warm?

21. angech,
I really don’t know how to explain the issue to you any more clearly.

For example, this

Because they are further away from the sun, less heat.

makes no sense.

And this,

In actual fact without increasing pressure the deep oceans should be frozen ice. The increasing pressure/compression keeps the water from freezing when it should. If you go below the ocean the temperature of the crust rises with increasing pressure.

is nonsense. Firstly, water is not an ideal gas – it is essentially incompressible. Also, as Ray Pierrehumbert explains in this comment

the equation of state for water does not come close to the liquid/solid transition even at the large pressures of the bottom of the ocean.

and

There is no reason the deep ocean would keep getting colder and colder. Liquid water is so opaque in the infrared, it really has no way of losing heat. ….

Since the densest water sinks, the temperature of the deep ocean is set by the temperature of the water at the surface that becomes dense enough to sink.

22. angech writes: Because they are further away from the sun, less heat.

Wikipeadia: “Earth is about 147.1 million kilometers (91.4 million miles) from the Sun at perihelion around January 3, in contrast to about 152.1 million kilometers (94.5 million miles) at aphelion around July 4 — a difference of about 5.0 million kilometers (3.1 million miles).”

Which is why New Year’s Day is warmer than the 4th of July. Oh wait a sec ….

23. Eli Rabett says:

Atmospheric pressure is determined by the composition of the atmosphere, the gravity of the Earth and the temperature of the surface (also to a smaller extent the absorption of sunlight in the atmosphere)

There, fixed that for you

24. izen says:

@-angtech
“If you go below the ocean the temperature of the crust rises with increasing pressure.”

The Earth has an internal source of heat from nuclear decay, it is not pressure dependent.

I am aware of the flaws in the sea pressure – temperature argument. But I have found that if pressure is invoked as a determining component of surface pressure, raising the ocean pressures elicits an explanation that either also refutes the pressure argument, or are so patently ridiculous (closer to the Sun?!) that it destroys the argument.

25. Steven Mosher says:

Angech

Here is a skeptical position you can hold and defend……

26. Steven Mosher says:

How do blankets warm?

unicorns cannot be ruled out

27. angech says:

“Here is a skeptical position you can hold and defend……”
People can pile on happily misinterpreting my statement.
The sun heats the water. The deeper the water the less sunlight that reaches it. The deeper water is further from the sun, hence further from the sun energy which is absorbed in the top two hundred meters.
That is what was meant.
That is why the water is cooler at depth.
“why are the deep oceans colder than the surface ?”

ATTP, “Firstly, water is not an ideal gas – it is essentially incompressible”
The ideal liquid is considered incompressible. Water is a real, not an ideal liquid.
“The low compressibility of non-gases, and of water in particular, leads to their often being assumed as incompressible. The low compressibility of water means that even in the deep oceans at 4 km depth, where pressures are 40 MPa, there is only a 1.8% decrease in volume.”
Further all solid and liquids are very compressible at depth under great pressure. Water exists in a liquid state at depth in the crust. Under huge pressures, 15 GPA, a lot more than at the bottom of the sea, the volume of water is 50% or more smaller than at 1 GPa.[and still liquid, not steam!]
The pressures to compress water by 1.8% in the deep ocean are associated with temperature changes which keep the water from freezing, not just the salinity.

Perhaps he could confirm whether there is ice in the crust, though not as we know it.
“Ice VII is a cubic crystalline form of ice. It can be formed from liquid water above 3 GPa (30,000 … It can also be created by increasing the pressure on ice VI at ambient temperature”

28. dikranmarsupial says:

Of course it was pointed out to angech that water is essentially incompressible on the thread containing Ray Pierrehumbert’s excellent comment, but he didn’t accept it there and I don’t suspect he will accept it here.

Angech hijacks yet another thread, he repeatedly behaves like this and then complains about moderation!

29. angech says:

No Unicorns.
The GHG effect is there and explains the surface temperature.

30. angech says:

dikranmarsupial says:
We have cross posted.

31. angech,

The sun heats the water. The deeper the water the less sunlight that reaches it. The deeper water is further from the sun, hence further from the sun energy which is absorbed in the top two hundred meters.
That is what was meant.
That is why the water is cooler at depth.

Except this isn’t correct, as Ray’s comment highlights. The oceans are dynamic. Cold water is denser than warm water. Therefore, what essentially happens is that cold, dense water at the poles sinks and also moves in latitude. This is what sets the temperature at the bottom of the ocean. It’s not set by how deep sunlight can penetrate (which, will, influence the temperature near the surface, but isn’t relevant to the temperature of the deep ocean, other than in how it heats the water that sinks).

The ideal liquid is considered incompressible. Water is a real, not an ideal liquid.

It’s still not an ideal gas, so it’s not true that there is some kind of simple relationship between pressure and temperature. The pressure will slightly compress and heat the water, but this isn’t why it doesn’t freeze.

Perhaps he could confirm whether there is ice in the crust, though not as we know it.

Ray basically answered this in his commentAs others have noted, the equation of state for water does not come close to the liquid/solid transition even at the large pressures of the bottom of the ocean.

32. verytallguy says:

The sun heats the water. The deeper the water the less sunlight that reaches it. The deeper water is further from the sun, hence further from the sun energy which is absorbed in the top two hundred meters… …That is why the water is cooler at depth.

No Angech, this really isn’t the reason water is cooler at depth.

Think about it. The centre of the Earth is *hotter* than the surface. Yet the depth of the ocean is *colder*; there is a minimum temperature in the system. There cannot be colder temperatures below the surface if heat gain at the surface is the driver.

The reason the oceans are colder at depth is the overturning circulation. Have a read.

https://www.gfdl.noaa.gov/bibliography/related_files/jrt9401.pdf

33. dikranmarsupial says:

Given Prof. Pierrehumbert wrote (in the first paragraph) ” And (small though the effect is), heat is coming OUT of the hot interior of the earth into the ocean, not going the other way.” one wonders why we should expect to see ice in the crust?

“People can pile on happily misinterpreting my statement.” yes, that is generally the intention of trolling.

“Further all solid and liquids are very compressible at depth under great pressure. ”

Citation required. Angech made this claim on the other thread as well

Different to a liquid at the surface (depths) but if one goes 40 kilometres down say a metal cannonball might conceivably be half the volume for the same mass. Happy to be proved wrong.

This is just bullshitting. In science you don’t make an absurd claim without evidence that what you say is actually true and expect other people to prove you wrong. In science the onus is on you to check that your own arguments are correct.

34. dikranmarsupial says:

The compressability of iron seemed an interesting topic, so I googled it and found this paper , which contains this figure:

Which suggests that to double the density of a sample of iron would take a pressure of about 10^3 GPa, which is 10,000,000 atmospheres of pressure. Assuming 10m per atmosphere, this would require an ocean 1000km deep (also assuming my calculations are correct). However, the paper (which I don’t understand) seems to be discussing compression due to a shock wave, whether that would also apply to static compression, I don’t know.

According to Wikipedia, above 10GPa iron exists in a hexagonal close packed allotrope, which presumably would be accompanied by an increase in density.

If there is a big increase in density with pressure after that, it would seem hard to explain how the Earth has a density of “only” 5.5g cm^3, given ordinary iron has a density of 7.87 g/cm^3.

However, I am no expert, just someone indulging their curiosity.

35. JCH says:

The oceans are a junkyard for sunlight that finally ran out of gas and was stranded just below the surface. We’re too far away from the sun for it to reach the bottom.

36. dikranmarsupial says:

angech says: October 10, 2017 at 7:30 am

dikranmarsupial says:
We have cross posted.

I don’t think anybody has any objection to you commenting here. I certainly don’t, in fact I think it is great to have climate skeptics posting here. However if you repeatedly fail to observe the norms of rational discussion, even after multiple requests to desist, then (i) you should expect criticism of your behaviour and/or (ii) that you will discourage those who do want rational discussion of the science (rather than just partisan sniping) from participating here. In short, if you don’t like me pointing out that you repeat arguments that have already been addressed on previous thread, then don’t do it. If you don’t like me pointing out your bullshitting (in the sense of Frankfurt), then don’t do it. Don’t present assertions that are plainly incorrect and present them as fact. Don’t make assertions without providing solid evidence to support them. Don’t assume that if you disagree with the worlds top scientists on fundamentals that the error lies with them not you.

The ball is in your court, ATTP has twice pointed out to you that water is essentially incompressible, according to Wikipedia (which you cite) there is only a 1.8% reduction in volume at 4K depth in the ocean, yet you assert as a fact that the heat from this tiny amount of compression is what prevents the water from freezing, not the salinity:

“The pressures to compress water by 1.8% in the deep ocean are associated with temperature changes which keep the water from freezing, not just the salinity.”

So where is your calculation of the heat generated by this compression to justify your assertion of fact?

37. dikranmarsupial says:

BTW I am not suggesting that an answer to that question would save angech’s theory, it wouldn’t, I’m just pointing out an assertion of fact with no supporting evidence, so that even if angech can’t provide the calculation, he might at least explicitly admit the assertion of fact had no supporting evidence.

The rise in temperature you get from compressing something is a transient event. If you compress air in a bicycle pump, yes it warms up a bit, but holding it at that pressure doesn’t keep it warm, it will (quite quickly) equilibrate by radiation and conduction and return to ambient temperature. If just keeping a gas or liquid under pressure kept it warm indefinitely, we would have a free source of unlimited energy (and have violated the first law of thermodynamics).

38. dave s says:

Nice article, a minor quibble about the statement that at the time of Kelvin and Helmholtz in the 19th century “it was also known that the Earth (and, hence, the Sun) was probably billions of years old” – geologists had been reluctant to put figures on the antiquity of the Earth, and don’t seem to have proposed billions.

The geologists Charles Lyell and Charles Darwin held that the Earth was indefinitely old, and in 1859 Darwin published his estimate of 300 million years for erosion of the Weald. In response, the geologist John Phillips put a figure of 96 million years for the oldest sediments.
Thomson (later enobled as Lord Kelvin) discussed the argument with Phillips, and in 1862 published calculations that the sun had heated the Earth for between 100 and 500 million years, and the Earth’s crust was possibly 98 million years old, otherwise not more than 400 million years old.
http://courses.seas.harvard.edu/climate/eli/Courses/EPS281r/Sources/Earth-age-and-thermal-history/more/Kelvin-1863-excerpts.pdf

Thomson’s calculations used Helmholtz’s 1856 concept of gravitational collapse as source of heat. Over the course of the century, Thomson (Kelvin) recalculated the age of the Earth as 20 million years, in conflict with the findings of geologists, but they found it hard to answer him…
http://onlinelibrary.wiley.com/doi/10.1029/2000JB900028/abstract

An early instance of a physicist being shown another field!

39. Magma says:

“if one goes 40 kilometres down say a metal cannonball might conceivably be half the volume for the same mass. Happy to be proved wrong — name withheld

I try not to be baited like this, but at the approximate 1 GPa pressure at a depth of 40 km within the Earth’s crust, the molar volume of bcc iron is only 0.5% less than at ambient pressure. (Correcting for a temperature of ~1000 °C complicates the calculation without changing the answer much, since apart from thermal expansion there’s also a phase change to the fcc structure.)

(first attempt went to moderation probably due to inclusion of the t-word — used a synonym)

40. dave,
Thanks. I was rather glib about the history, so thanks for clarifying some of that.

41. Willard says:

­> Think about it. The centre of the Earth is *hotter* than the surface. Yet the depth of the ocean is *colder*; there is a minimum temperature in the system. There cannot be colder temperatures below the surface if heat gain at the surface is the driver.

How clever, Very Tall, but it’s blankets all the way down.

42. verytallguy says:

it’s blankets all the way down.

Actually, it’s turtles all the way down.

[strange coincidence – I’m just reading the excellent “science of discworld”. Climate “sceptics” might well have their own guild…]

43. Magma says:

@verttallguy:

As I recall — it’s been a while — Discworld is supported by four giant elephants standing on the back of a single enormous turtle swimming through space. The oceans do pour off the edge of the world, but I can’t remember whether Terry Pratchett devised a return flow system for all that seawater and marine life.

44. WT says:

Write more about astrophysics, you do it so well.

45. WT,
Thanks.

46. Phil says:

Phil that is a somewhat confused tale about collisional broadening which “fills in” the spaces between the rotational lines, however it is also completely wrong to say that there is no absorption by isolated molecules and that O2 and N2 do not collisionally broaden the CO2

Eli, as ATTP correctly states, none of my comment referred to collisional broadening, which is a completely different phenomenon. I have no idea how you got the idea that I thought that O2 and N2 do not collisional broaden ????

It should be obvious, I hope, that in a complex such the one I described; O=C=O…H-O-H, there will be normal mode of vibration that looks something like the H-O-H bend vibration in the uncomplexed pure H2O (and similar for the asymmetric stretch, the now no-longer symmetric stretch, and the vibrations in the CO2 molecule). These vibrations will probably have a similar(ish) force constant (since the complex is weak), but the fact that it has the mass of a CO2 hanging off one the hydrogen atoms, will shift the frequencies somewhat, and the fact that the whole entity is considerably larger, will give it a larger moment of interia, thus smaller B,C and A rotational constants and so closer spaced ro-vibrational structure. This is, from a spectroscopic point of view, a completely separate “species”, that by its nature happens to have vibrational frequencies that will lie close to or over the bands in the un-complexed monomer.

Water dimers do, but not the things phil was writing about.

This has me even more confused, since water dimers were one of the things I specifically mentioned in my original post

I hope that’s made things clearer, but then again, I thought my initial post was pretty clear, and I’m very confused as to how it could be so wrongly interpreted.

VTG – yes I understood the point about the low concentration of these species in the atmosphere. Without knowing exactly how they respond to pressure and temperature, its difficult to be sure, but I guess if the idea has sunk without a trace then its not needed as part of the explanation. Part of the motivation of my post was to find out what, if anything, had happened to the idea. I also thought it may be of interest for studying other, less hospitable, atmospheres than Earths.

47. angech says:

Thanks Dikran

48. angech says:

Magma says: October 10, 2017 at 1:54 pm
At the approximate 1 GPa pressure at a depth of 40 km within the Earth’s crust, the molar volume of bcc iron is only 0.5% less than at ambient pressure.”

I was proved wrong.
Happy to have a misunderstanding on the amount of compression of solids cleared up.
Reading on eruptions I was sure I had read that the substances expanded massively as they were released from the pressure they had been under. Perhaps some other materials have lower BM than iron.

Bulk modulus is a property of virtually all solids and liquids and is a measure of their compressibility under pressure.

The value of the bulk modulus for steel is about 2.3 × 107 psi, or 1.6 × 1011 pascals, three times the value for glass. Thus, only one-third the pressure is needed to reduce a glass sphere the same amount as a steel sphere of the same initial size. Under equal pressure, the proportional decrease in volume of glass is three times that of steel. One may also say that glass is three times more compressible than steel. In fact, compressibility is defined as the reciprocal of the bulk modulus

49. dikranmarsupial says:

angech, it is good that you have admitted that you were wrong, but I fear you are still missing the point. The onus should not be on us to debunk your claims and assertions of fact, the onus should be on you to make sure that your arguments are well supported before you make them, especially if you are disagreeing with the worlds top scientists (who most definitely have taken the time to check the validity of their arguments!). As far as I can see, that is a fundamental requirement of truth-seeking scientific discussion.

I note you have not addressed the evidence for your central cliam, that:

“The pressures to compress water by 1.8% in the deep ocean are associated with temperature changes which keep the water from freezing, not just the salinity.”

50. Eli Rabett says:

Phil, each of the things you talk about have IR signatures which would be seen. Even the presence of water vapor dimers which would be by far the most likely are a subject of contention as to whether they HAVE been observed.

In short, no. You can see these complexes under well controlled experimental conditions with care with care, but they have nothing to do with IR absorption in the atmosphere.

51. “The onus should not be on us to debunk your claims and assertions of fact, the onus should be on you to make sure that your arguments are well supported before you make them, especially if you are disagreeing with the worlds top scientists (who most definitely have taken the time to check the validity of their arguments!). “

The problem is that Angech lacks the physics insight to get a rise out of anyone that matters.

Yet, there are always cases where the “top scientists” are intrigued by something new that pops up … but the innovators have to possess some credentials. This is a recent case in point:

“Topological Origin of Equatorial Waves” : https://arxiv.org/pdf/1702.07583.pdf

The researchers spotted the connection, says Marston, through “intuition about the underlying physics” – particularly in the way that both magnetic fields and planetary rotation break time-reversal symmetry.

Atmospheric scientist Isaac Held of the US National Oceanographic and Aeronautical Administration’s Geophysical Fluid Dynamics Laboratory at Princeton University agrees that this is a new interpretation of these equatorial waves. He thinks that the fresh perspective might help to understand why they are so robust, for example in the face of random noise in atmospheric or oceanic flows.
http://physicsworld.com/cws/article/news/2017/oct/10/do-topological-waves-occur-in-the-oceans

Is this research going to go anywhere? Since topology doesn’t change over time, we need to ask whether topological waves will lead to deterministic patterns in climate cycles.

52. Dikran Marsupial says:

Paul, not bullshitting is a (minimal) requirement of all truth seeking scientific discussion, at any level, in any company, whether it is someone that “matters” or not (happy to admit I don’t ;o) However extraordinary claims require extraordinary evidence, so if you are opposing the mainstream position on basic and fundamental issues (as angech regularly does) you need to provide strong evidence, rather than just state your opinion as if it were a fact and challenge others to prove you wrong.

Trouble is too many blog discussions are primarily about getting a rise out of somebody. I am reading Tim Berners-Lee’s Book “weaving the web”. I suspect this was not quite what he had in mind! ;o)

Those going against mainstream scientific opinion generally do change minds, provided they supply the evidence and are willing to engage constructively with criticism of their theory. Credentials not always that important, e.g. patent clerks can make a modest contribution from time to time!

53. I am interested in work that looks at the geophysics from a different perspective. One of the co-authors (Brad Marston) of the link above wrote a Physics Today paper : “Trend: Looking for new problems to solve? Consider the climate” — https://physics.aps.org/articles/v4/20
The subheading says ” physicists should not ignore the intellectual challenge of trying to model climate change.”

And this paper by Vallis is a good inspiration to look at simplifying the physics before doing CFD
Vallis GK. 2016 “Geophysical fluid dynamics: whence, whither and why?” Proc. R. Soc. A 472: 20160140.

54. angech says:

dikranmarsupial says:
“I note you have not addressed the evidence for your central claim, that:
“The pressures to compress water by 1.8% in the deep ocean are associated with temperature changes which keep the water from freezing, not just the salinity.”

It is hard to admit being wrong.
I would hope that one or more of the many commentators here would be able to corroborate this claim, or parts of it. I will try to put some more work into it for you over the coming months.

There are more issues than just static pressure with the composition of the water at the bottom of the sea. There is the heat input to the surface 12 hours a day on average. There are the gravitational effects of the moon, sun and microscopically the planets. There is heat input from the earth. There is the salinity and freezing point and water density problems. And finally the tidal circulations. Yet…

Pressure and temperature are directly interlinked, given all the other conditions are known.
“At the bottom of the Mariana trench the water column above exerts a pressure of 1,086 bars (15,750 psi), more than 1,000 times the standard atmospheric pressure at sea level. At this pressure, the density of water is increased by 4.96%, so that 95 liters of water under the pressure of the Challenger Deep would contain the same mass as 100 liters at the surface.
It reaches a maximum-known depth of 10,994 meters.”

Now the temperature of water at 1000 meters is the same as the temperature at 11,000 meters yet the water is much denser than at the surface or 1000 meters.So why does the thermocline level out at depth rather than the temperature continuing to go down?
It cannot be because of heat from the earth. As we have been told water is a poor conductor of heat and the heat is the same temperature all the way down from the thermocline. My contention is that the thing that stops the water from freezing is the increasing pressure at depth.

I hope this statement addresses some of the claim.

“So where is your calculation of the heat generated by this compression to justify your assertion of fact?”

Density of a substance at a given temperature and pressure determines the amount of energy contained in the substance. The heat generated by this compression might be visualisable through the concept of Potential heat. If you were to take a cubic meter of water from 11000 meters to the surface it would expand by 4.6% That expansion needs heat. The heat in that cubic 0.046 cubic meters would be the same heat generated by compression.

55. dikranmarsupial says:

One last fisking of angech’s comment:

It is hard to admit being wrong.

(i) The problem is not that you are repeatedly wrong, but that you repeatedly assert obviously incorrect statements as facts, and do not take the trouble to determine the truth of your arguments before you make them, which is bullshitting.

(ii) if you have the right attitude, it is not hard to admit being wrong (unpleasant perhaps, but not hard to do). Here is me doing exactly that on this very topic on the previous thread. Did I enjoy exposing the flaw in my intuition? No. Did it stop me from admitting my error and being corrected? No. Was I glad to have improved my intuition as a result? Yes. Pride is not a good quality if it gets in the way of discovering the truth. Note I made it easier to accept being wrong by clearly indicating my lack of real expertise and posing it as a question, rather than a fact.

I would hope that one or more of the many commentators here would be able to corroborate this claim, or parts of it. I will try to put some more work into it for you over the coming months.

It would be better if you paid some attention to the counterarguments, rather than just carrying on looking for evidence that you are right.

There are more issues than just static pressure with the composition of the water at the bottom of the sea. There is the heat input to the surface 12 hours a day on average. There are the gravitational effects of the moon, sun and microscopically the planets. There is heat input from the earth. There is the salinity and freezing point and water density problems. And finally the tidal circulations. Yet…

This is evasion. Your claim was that

“The pressures to compress water by 1.8% in the deep ocean are associated with temperature changes which keep the water from freezing, …

and none of that provides any support for your contention.

Pressure and temperature are directly interlinked,

This is another of those unsupported assertions. *HOW* are they directly interlinked. As I pointed out if you compress air in a pump it heats up, but it doesn’t stay hot even if you maintain the pressure.

given all the other conditions are known.
“At the bottom of the Mariana trench the water column above exerts a pressure of 1,086 bars (15,750 psi), more than 1,000 times the standard atmospheric pressure at sea level. At this pressure, the density of water is increased by 4.96%, so that 95 liters of water under the pressure of the Challenger Deep would contain the same mass as 100 liters at the surface.
It reaches a maximum-known depth of 10,994 meters.”

So, what do all of those large numbers quoted from Wikipedia tell us about the heat generated by that compression? Nothing.

BTW if you are going to quote, give the source, and if you are going to put it in quotes then itshould be a direct quote (perhaps with … to show elisions), rather than your own paraphrase. Especially as you have been guilty of deeply misleading selective quotation in the past.

Now the temperature of water at 1000 meters is the same as the temperature at 11,000 meters yet the water is much denser than at the surface or 1000 meters.So why does the thermocline level out at depth rather than the temperature continuing to go down?

My understanding (note I’m not stating this as a fact) is that the thermocline is due to waves mixing the upper layer of the ocean, which rapidly distributes the heat absorbed at the surface. I don’t think you first statement is even true, this diagram from a Wikipedia article suggests a drop of about 4C.

It cannot be because of heat from the earth. As we have been told water is a poor conductor of heat and the heat is the same temperature all the way down from the thermocline.

AIUI water is actually a moderately good conductor of heat, which is why you die of hypothermia in cold water rather faster than you would in air at the same temperature. If you are referring to Prof. Pierrehumbert’s comment:

There is no reason the deep ocean would keep getting colder and colder. Liquid water is so opaque in the infrared, it really has no way of losing heat. Vertical heat transport is fairly small, but insofar as it’s there, the vertical heat transport is downward. And (small though the effect is), heat is coming OUT of the hot interior of the earth into the ocean, not going the other way.

I don’t think it is a simple as water being a poor conductor as it is a statement about radiation rather than conduction. If water were transparent to IR then the deep ocean could loose heat directly to the surface by radiation, but it can’t so it can only loose it by convection or conduction. The rate at which it looses heat by conduction would seem to me to depend on the thermal gradient, which would be low because of the depth of water that it must span. This seems in accord with the Wikipedia diagram, with the change in rate above the thermocline being explained by the physical mixing of the surface layers. Note also that temperature declines with depth, the transfer of heat is in the other direction anyway!

My contention is that the thing that stops the water from freezing is the increasing pressure at depth.

At least this is stated as you contention, rather than as a fact.

I hope this statement addresses some of the claim.

Well no, you haven’t provided any additional supporting evidence whatsoever.

I wrote

“So where is your calculation of the heat generated by this compression to justify your assertion of fact?”

angech replies:

Density of a substance at a given temperature and pressure determines the amount of energy contained in the substance. The heat generated by this compression might be visualisable through the concept of Potential heat. If you were to take a cubic meter of water from 11000 meters to the surface it would expand by 4.6% That expansion needs heat. The heat in that cubic 0.046 cubic meters would be the same heat generated by compression.

Translation “I have no such calcuation, so here is yet more unsupported/unreferenced assertion” Iopen to the possibility that my understanding is incorrect, but if you want to show that the effect of compression driven heating is non-negligible, then you need a calculation of its expected magnitude, not arm-waving and assertion

56. dikranmarsupial says:

apologies, I think I have the world record safely established for most tags messed up in one post! 😦

[Mod: fixed.]

57. dikranmarsupial says:

Thanks Mod, much appreciated! The picture I mean to include was this one:

Given that angech has responded to a criticism of presenting incorrect assertions as being facts, by making another incorrect assertion as being a fact, I think I’ll leave it there.

58. Windchaser says:

Pressure and temperature are directly interlinked, given all the other conditions are known.

Yes, but not for the reasons you mention. Pressure and temperature are directly linked on the phase diagram; there is a temperature at which water is densest. Water at this temperature will sink; water below or above this temperature will rise.

Pressure makes this more important. The greater the pressure differential, the greater the driving force for less-dense water to rise and give way to denser water.

So why does the thermocline level out at depth rather than the temperature continuing to go down?

Because, when the temperature decreases even more, that water gets less dense, and it would rise.

Deep water is at the temperature where water can be densest. The intense pressure drives it to be so; water at lower or higher temperatures self-separates and rises.

59. Windchaser says:

Density of a substance at a given temperature and pressure determines the amount of energy contained in the substance.

This is incorrect. =\

Density (weight per volume) doesn’t determine internal energy. Sure, temperature + entropy together does (SdT), as does the combination of pressure and volume (PdV). And those have their own coefficients which determine how effective they are for storing energy.

But in neither case does density nor pressure determine the amount of energy contained in a substance. You need other information to determine that. This whole “it’s denser, therefore it must have much more energy” thing is wrong; contrary to the laws of physics and thermodynamics.

It feels like you went to class and listened to the lectures, but you didn’t quite get it, and your answer on the test is kinda half-right… but ultimately, it leaves out some really key points, some key understanding of how the physics works.

Go read and learn. Or come with questions. But don’t speak confidently out of ignorance; learn first and then speak. An uninformed opinion isn’t worth much.

60. angech says:

Windchaser,
E=mc2.
I am right.
Why did you want to move goal posts from energy to internal energy?

61. angech says:

Windchaser
“Because, when the temperature decreases even more, that water gets less dense, and it would rise.”

62. angech says:

That would seem to be a good reason for that curve DM put up, thank you.

63. Eli Rabett says:

In fluids which include liquids and solids temperature pressure and density are linked by an equation of state. There are sophisticated eqs of state beyond the van de Waals that do a good job over wide ranges but those are more the property of chemical engineers than scientists.

That makes a lot of this discussion sadly vanish into handwaving.

64. Eli,

In fluids which include liquids and solids temperature pressure and density are linked by an equation of state.

Yes, exactly.

65. Dikran Marsupial says:

Eli wrote “That makes a lot of this discussion sadly vanish into handwaving.”

A lot of science is like that, which is why a bit of humility is a good thing. Some basic principles can be easily understood, but going from there to a useful quantitive description often is rather more difficult (I.e. effectively beyond the reach of the lay person, which is why we have scientists).

66. Since we’re discussing equations of state, I’ll mention something that may make their relevance clearer. In hydrodynamics (or fluid dynamics/gas dynamics – studying the flow of fluids/gases) you typically solve a set of equations that include mass conservation (often expressed in terms of density), momentum conservation (solving for velocity, essentially) and energy conservation (often either expressed as an energy density, or entropy). In order to evolve the mass conservation equation, you need to know the fluid/gas velocities, and to evolve the momentum equation, you need to know the fluid/gas pressures (since a pressure gradient is a force). In order to complete these equations, you then need an equation of state, that either relates pressure, density and temperature, or pressure and energy density. This is the equation of state and, in the case of hydrodynamics, is often referred to as a closure relation.

The equation of state, by itself, can’t tell you how the fluid/gas will evolve (which is a mistake those who promote the pressure determines the surface temperature argument make), but you also can’t understand the evolution of a system without some kind of equation of state.

67. Magma says:

There are sophisticated eqs of state beyond the van de Waals that do a good job over wide ranges but those are more the property of chemical engineers than scientists. — Eli Rabett

Or in some cases geophysicists, planetary scientists, and high-pressure mineralogists & petrologists.

Dorogokupets et al. (2017) Thermodynamics and Equations of State of Iron to 350 GPa and 6000 K
http://www.nature.com/articles/srep41863

68. “In order to evolve the mass conservation equation, you need to know the fluid/gas velocities, and to evolve the momentum equation, you need to know the fluid/gas pressures (since a pressure gradient is a force). “

This set of equations is known as the primitive equations. One useful approximation to this set is a linearization known as Laplace’s tidal equation. What’s interesting about this is that even though Laplace intended to use these for estimating tides, it’s rare to see these used for tides, as it’s much more common to apply the lunisolar forcing periods and assume a forced response.

But for general climate such as for atmospheric and oceanic waves, the tidal equations are often used — yet the lunisolar forcing aspect is typically buried in the GCMs if it is there at all. Still don’t know why this is, even though these forces obviously have an impact on the behavior.

69. Windchaser says:

Why did you want to move goal posts from energy to internal energy?

angech, what did you mean by “energy contained in the substance” if not internal energy?

Can you provide the mathematical formulation for measuring this energy? That’d help; otherwise it kinda feels like you’re just kinda handwaving.

70. angech says:

(I.e. effectively beyond the reach of the lay person, which is why we have scientists).
I think I had children at the same i me as the Apple Mac and the new fanged TV controllers.

71. angech says:

do know more about the arcane nitty gritty. Now I am 99% retired I hope to devote more time to both fields, one is never to old to learn.

72. angech says:

Eli,
“In fluids which include liquids and solids temperature pressure and density are linked by an equation of state.”
Thanks, I think?.
DM
Roy Spencer circa 2012 debunking Nikolov, but not the fact that compression can cause non negligible heating, still no figures for you.
“Thought Experiment #2 on the Pressure Effect
Imagine we start with the atmosphere we have today, and then magically dump in an equal amount of atmospheric mass having the same heat content. Let’s assume the extra air was all nitrogen, which is not a greenhouse gas. What would happen to the surface temperature?
Ned Nikolov would probably say that the surface temperature would increase greatly, due to a doubling of the surface pressure causing compressional heating. And he would be correct….initially.”

73. angech says:

“At the center of a planet or star, gravitational compression produces heat by the Kelvin–Helmholtz mechanism. This is the mechanism that explains how Jupiter continues to radiate heat produced by its gravitational compression.”

74. angech,

Ned Nikolov would probably say that the surface temperature would increase greatly, due to a doubling of the surface pressure causing compressional heating. And he would be correct….initially.”

Except it would very quickly be radiated back into space if there was not also an increase in the planetary greenhouse effect due radiatively active gases.

I’m not sure what the point of the quote in your most recent comment is. It is true for Jupiter, because it is very massive, it is predominantly a gaseous atmosphere, and a very slow contraction can continue to release energy. It isn’t relevant for the Earth’s atmosphere.

75. Dikran Marsupial says:

Angech, I am not interested in your repeated bullshit. For a start you haven’t even had the basic decency to admit that your new claim:

Now the temperature of water at 1000 meters is the same as the temperature at 11,000 meters

Is incorrect, or at least you have ignored my evidence that it isn’t true. Why should I be interested in listening to you, when you repeatedly ignore what I say to you?

The spencer argument obviously isn’t relevant in this case, as we haven’t increased the mass of the atmosphere or the ocean. Nikolov would be right in a situation that does not apply to the current Earth, which I suspect was entirely Dr Spencer’s point!

The Kelvin-Helmholtz mechanism was brought up in the very first comment on the previous thread on this topic, and the reason why it is not relevant has already been pointed out on this thread (the heat of compression is a transient event, it doesn’t keep the gas/fluids warm as that heat is radiated away).

76. Dikran Marsupial says:

Angech is engaging in dishonest selective quoting again, here is the full Spencer thought experiment:

Thought Experiment #2 on the Pressure Effect
Imagine we start with the atmosphere we have today, and then magically dump in an equal amount of atmospheric mass having the same heat content. Let’s assume the extra air was all nitrogen, which is not a greenhouse gas. What would happen to the surface temperature?

Ned Nikolov would probably say that the surface temperature would increase greatly, due to a doubling of the surface pressure causing compressional heating. And he would be correct….initially.

But what would happen next? The rate of solar energy absorption by the surface (the energy input) would still be the same, but now the rate of IR loss by the surface would be much greater, because of the much higher surface temperature brought about through compressional heating.

The resulting energy imbalance would then cause the surface (and overlying atmosphere) to cool to outer space until the rate of IR energy loss once again equaled the rate of solar energy gained. The average temperature would finally end up being about the same as before the atmospheric pressure was doubled.

The bit in bold is the bit angech left out, and It explicitly explains why that thought experiment in no way supports Nikolov’s theory, but he has managed to waste ATTP’s time and mine with disingenuous trolling. It is not as if this is the first time angech has used this ploy either. I agree with BBD, this is “flat-out unacceptable” behaviour.

77. Dikran – your example of angech’s selective quotation is a prime example of what I categorize as ‘bad faith’ participants in an online discussion. Good faith participants are actually interested in learning (or teaching). Good faith participants defend their views honestly, acknowledge when they’re wrong or when others are correct. Bad faith participants are just a waste of time. I have no problem insulting or ridiculing them because they’ve forfeited any right to civility.

78. Maybe we could avoid piling on, and maybe angech (if they really are trying to engage in good faith – which is no longer obvious) could reflect in this before posting another comment.

79. Dikran Marsupial says:

Of course nobody would claim that compression doesn’t cause heating, I gave the example above that compressing air in a bicycle pump warms the air inside, but it doesn’t stay warm just by keeping it compressed, for the same reason that Spencer, ATTP and myself pointed out, so it was a straw man from the outset, but angech should have given the whole quoted to show why it was utterly irrelevant to the discussion.

80. As I understand it, angech is a doctor (happy to be corrected). I wonder what angech would think if someone was publicly posting comments about medical treatments that were known by the medical establishment to not only not work, but to potentially harm those taken in by those who promoted such treatments.

My point is that there are things that are essentially known to be true by those who have relevant expertise. It is frustrating to see people who don’t have such expertise saying things that essentially undermine that understanding. There’s a difference between actually asking questions and just asking questions.

81. Joshua says:

I wonder what angech would think if someone was publicly posting comments about medical treatments that were known by the medical establishment to not only not work, but to potentially harm those taken in by those who promoted such treatments.

angech –

“[T]he arguments presented against the HIV hypothesis are sound…Just being gay causes AIDS: …median age at death for homosexual men dying of AIDS is 39 years and…for homosexual men who do not die of AIDS is 42. By comparison, the value for heterosexual married men is 75…This is evidence in support of the hypothesis that AIDS may be little more than a general classification of deaths resulting from exposure to homosexual behavior…..Only government reclassification of more and more disease types as AIDS cases has kept the numbers of victims at politically necessary levels.”

Now keep in mind that the source of those quotations was a very prominent “skeptic”

“He’s one of the founders of this whole movement,” says Joseph Bast, CEO of the Heartland Institute, which has served for 20 years as the leading think tank of the push to challenge climate science….. “Time will tell,” he promised, “but it certainly seems like [person X’s] views are winning the day.”That review of climate science has been hugely influential among climate skeptics, says Bast, precisely on account of its simplicity. “It was a standard reference tool and an important publication,” he explains. “Art was one of the first to say, ‘This isn’t too hard for the layman to figure out.’ … You can go through it, even though you’re not a scientist, and say, ‘You’re right, that doesn’t make sense.’”

https://fivethirtyeight.com/features/the-grandfather-of-alt-science/

And keep in mind that some very powerful people may be advocating that this individual be appointed to be Trump’s science adviser:

So let’s also keep in mind that it’s a form of a fallacy to implicate the entire “skeptic” community because one prominent “skeptics” has some dubious vies about medical science (at one point in time, at least)… and that it’s a form of ad hom fallacy to attack this individual’s views on climate change because of his previously stated views on AIDS, but I do think that the mechanisms that play out with Mr. X’s role in the medicine/science/public policy interface are relevant to your interaction here. That isn’t to say that I think that you shouldn’t post comments that question the perceived “consensus” view on climate science, but that maybe you should think harder about decoupling your comments from their potential to convey a certain conspiratorial mindset about climate scientists?

* I apologize for the use of all of those ellipses – but you can find links here:

82. “Bad faith participants are just a waste of time.”

Kevin, I learned by previously dealing with angech, who is one of the huge cabal of skeptic Australian commenters at Judith Curry’s blog. Often 50% of comments there are from Australia. Looking into why this is the case, I found that there is a long tradition of contrarianism built into the Australian cultural psyche.

http://theconversation.com/larrikin-carnival-an-australian-style-of-cultural-subversion-42884

What Stephan Lewandowsky ought to do is figure out why the Aussie deniers have such a disproportionate stranglehold over the discussion in these forums. The British of course like to argue, but it is invariably for intellectual stimulation, whereas the Australian larrikins do it to irritate others, which apparently is sport to them.

83. angech says:

Paul, Australian, so I think is Stephan, so may be a conflict of interest in trying to work out our intransigent ways.
Joshua, From your article his views on a lot of things seems a bit odd. It cross references Linus
Pauling who was brilliant in his field but may have got his views on Vitamin C a bit wrong. So people can be quite good in one area and not in another.
ATTP, I agree it is frustrating, on the other hand truths in medicine often seem to go in cycles , diabetic diets for instance where portions were insisted on only to be changed and changed again.
BP levels were pushed way down and now have been moved up again. A certain skepticism needs to be kept ready in the forefront of scientific knowledge.
Re “angech’ selective quotation , dishonest selective quoting again” etc I apologise since it gave people that impression. I cannot win sometimes. The quote ends with the word initially which implies extremely strongly that it was not the final situation. I referenced Roy Spencer who was supporting very strongly the anti it is all pressure view. (exactly “why that thought experiment in no way supports Nikolov’s theory,”). I wrongly thought that it was all self evident, not dishonest and not tongue in cheek.
If I had left out the initially I would concur with all those comments. Anyway, sorry.

84. angech says:

Dikran Marsupial says:
October 14, 2017 at 8:38 am
“Angech, I am not interested in your repeated bullshit. For a start you haven’t even had the basic decency to admit that your new claim:Now the temperature of water at 1000 meters is the same as the temperature at 11,000 meters Is incorrect, or at least you have ignored my evidence that it isn’t true. Why should I be interested in listening to you, when you repeatedly ignore what I say to you?”
“I don’t think you first statement is even true, this diagram from a Wikipedia article suggests a drop of about 4C.”

DM,
I took my comment from the same article which has a graph with this quote.
“Graph showing a tropical ocean thermocline (depth vs. temperature). Note the rapid change between 100 and 1000 meters. The temperature is nearly constant after 1500 meters depth.”
I did not respond to you initially because I do not want to upset you.
I hope this response is OK.

85. dikranmarsupial says:

Angech’s claim was

“Now the temperature of water at 1000 meters is the same as the temperature at 11,000 meters” [emphasis mine]

I challenged him to admit that was wrong and he comes back wit

““Graph showing a tropical ocean thermocline (depth vs. temperature). Note the rapid change between 100 and 1000 meters. The temperature is nearly constant after 1500 meters depth.” [emphasis mine]

The graph suggests the difference is about 4C. That is small compared to the rapid change above the thermocline, but the temperatures are not the same, which is what angech claimed. Does that matter? Well lets see angechs claim in context:

Now the temperature of water at 1000 meters is the same as the temperature at 11,000 meters yet the water is much denser than at the surface or 1000 meters.So why does the thermocline level out at depth rather than the temperature continuing to go down? [emphasis mine]

So yes, it is important, the temperature does continue to go down, so angechs apparent anomaly doesn’t actually exist.

No, it isn’t O.K. angech, you were wrong and should just admit it, rather than just continue evading the counter-argument.

” The quote ends with the word initially which implies extremely strongly that it was not the final situation. “

The bit that you left out contradicts your theory, which is why not quoting it as well is dishonest, even if you did hint with the “initially”. I shouldn’t have to go and find the context to find out that it also pointed out the error in your theory!

Since water at the bottom of the ocean is under the most pressure, it would make sense that it is at maximum density. Water at maximum density is 4C, No higher, no lower. The absence of sunlight at the bottom of the ocean is irrelevant. Therefore, the only way to have ice at the bottom of any part of the ocean would be if it were solid ice, from top to bottom.

87. Yail,

the only way to have ice at the bottom of any part of the ocean would be if it were solid ice, from top to bottom.

This is true because ice has a lower density than water and, hence, would rise. However, what you said before that isn’t quite correct for salt water. If the salinity is above 24.7 (most of the ocean is between 34 and 36) then the density of the water (seawater) increases with decreasing temperature for all temperatures above freezing. What you describe is for fresh water.

88. angech says:

“The pressures to compress water by 1.8% in the deep ocean are associated with temperature changes which keep the water from freezing, not just the salinity.”
So where is your calculation of the heat generated by this compression to justify your assertion of fact?

Is this appropriate?
Encyclopaedia Britanica seawater temperature distribution
“the temperature may be observed to increase slightly with depth. This occurs when the deepest parts of the oceans are filled by water with a single temperature from a common source. This water experiences an adiabatic temperature rise as it sinks. Such a temperature rise does not make the water column unstable, because the increased temperature is caused by compression, which increases the density of the water. For example, surface seawater of 2 °C (35.6 °F) sinking to a depth of 10,000 metres (about 33,000 feet) increases its temperature by about 1.3 °C (2.3 °F). When measuring deep-sea temperatures, the adiabatic temperature rise, which is a function of salinity, initial temperature, and pressure change, is calculated and subtracted from the observed temperature to obtain the potential temperature.”

“Further all solid and liquids are very compressible at depth under great pressure. ”
Re compressibility, you asked for a citation? It states
“Increasing density values demonstrate the compressibility of seawater under the tremendous pressures present in the deep ocean. If seawater were incompressible, each cubic centimetre of water in the water column would expand, and density values at all depths would be equal. If the average pressure occurring at a depth of 4,000 metres (about 13,100 feet, the approximate mean depth of the ocean) was somehow replaced with the average pressure that occurred at 2,000 metres (about 6,600 feet) and the area of the oceans remained constant, there would be an average sea level rise of about 36 metres (120 feet).”
I’m sorry it only refers to the individual case of seawater.

89. angech,
The compression of water at depth will increase the temperature slightly. That the temperature drops with depth means deep water can’t lose energy via conduction. The geothermal flux will also add some energy to the deep ocean. It’s also very opaque to infrared radiation, so can’t really lose energy via radiation. Therefore parcels of water in the deep ocean can’t easily lose energy. However, this water parcel probably started at the surface near the poles and sank because it was denser than the water below it. That it sank means it wasn’t frozen (otherwise it wouldn’t sink). Given that it is hard for such a parcel to lose energy (and may actually gain some) means it is very unlikely to then satisfy the conditions for freezing. That it doesn’t freeze is not simply because it gains some energy via compression.

90. angech said:

“Paul, Australian, so I think is Stephan, so may be a conflict of interest in trying to work out our intransigent ways.”

Of course Lewandowsky is Australian. That’s why he would be the right psychologist to investigate the source of Australian contrarianism on climate science blogs.

And why would that be a “conflict of interest”? You probably do know what a conflict of interest means but you toss out that remark because that is your nature — to be contrarily argumentative.

91. dikranmarsupial says:

Angech, great. The point is that you need to obtain that information before making the claim to avoid bullshitting (bullshit isn’t necessarily incorrect). As I said, it doesn’t rescue your theory anyway, lets go back to the start:

Izen: “If pressure determined temperature, why are the deep oceans colder than the surface ?”

angech “Because they are further away from the sun, less heat. In actual fact without increasing pressure the deep oceans should be frozen ice. The increasing pressure/compression keeps the water from freezing when it should. If you go below the ocean the temperature of the crust rises with increasing pressure.”

So we agree that the descending water gains some heat from compression as it travels to the bottom of the ocean. However the circulation of water in the ocean takes hundreds to thousands of years, so how does that small amount of heating keep the deep ocean waters from freezing for hundreds of years?

Hint: It doesn’t, as ATTP explains very clearly.

92. angech says:

I’m relatively happy. I have asked some questions and put forward some proposals that have lead to a lot of input, thanks DM , pointing out areas where I was wrong or needed to brush up on.
I have a much better understanding of the freezing of salt sea water which as ATTP pointed out a blog or 2 back behaves like most other normal fluids in that it’s density keeps increasing with cooling and does not, unlike fresh water, start to get less dense.
I understand that density, salinity, pressure and temperature all have a complex interrelationship and that ice has a unique ability to melt under pressure instead of getting more solid.
As ATTP also said the mechanism of freezing in salt water is much more complex than fresh water.
I keep learning, I look at gravity waves, atmospheric pressure changes winds and currents and I see that the sea floor is not like a bicycle pump, one press in and then the heat from the pressure dissipates. I see ongoing pumping.
The point is to keep on learning. Thanks.
Paul,
I would have though Australians investigating Australians about the quirks of Australian behaviour, particularly when they are all quirky, might have some conflict of interest. Relax and have a laugh at the thought even if we differ on the intent.
Nick S is Australian too, we bat on both sides.

93. Dikran Marsupial says:

I’m not so happy. Angech made a claim and repeatedly ignored criticism and now has walked away from the discussion without acknowledging that his claim was flat wrong, which means that he can troll it again for a third time when it next comes up.

There is no “ongoing pumping” – each parcel of downwelling water gets heated by compression once but then has to stay at the ocean floor for centuries, so what keeps it from freezing?

94. angech,

I see ongoing pumping.

Dikran is right, there is no ongoing pumping. A parcel of water that sinks can be compressed once. If it rises, it will expand very slightly and – consequently – cool very slightly. It really cannot continually gain energy via compression.

95. “Paul,
I would have though Australians investigating Australians about the quirks of Australian behaviour, particularly when they are all quirky, might have some conflict of interest. Relax and have a laugh at the thought even if we differ on the intent.
Nick S is Australian too, we bat on both sides.”

LOL! The distinction is that Nick Stokes is a PhD scientist who worked at the premier research organization of Australia CSIRO, with highly cited articles as proof. And he is actually doing interesting research on his own. His only quirkiness is that he believes that he can educate the people at WUWT to the errors in their thinking — which we all know is a hopeless cause.

96. That’s right. The only way that the ocean can gain energy in this way is by frictional dissipation, otherwise compression/decompression is a reversible process.

BTW, Reminder that in a couple of days it will be Walter Munk’s 100th birthday, who initially established that deep ocean mixing is being largely driven by the turbulence caused by tidal forces. The effect of the moon is subtle but it is responsible for much of the cyclic natural variation we see in climate measures.
http://www.nature.com/news/role-of-chaos-in-deep-ocean-turned-upside-down-1.19455

97. Magma says:

This February Munk was honored at an oceanography conference in San Diego, and in accepting the award stated that climate change required a response on the scale and urgency of the American response to WWII. I can’t find a transcript or recording, but he may have also added that the Allies rose to that challenge. There was the added weight of history in his comments, since he worked as a US Navy oceanographer helping to forecast D-Day waves and tides.

98. Thanks, I will have to keep an eye out for that transcript. Here is a link to an article on Monk’s birthday from Scripps
http://contextearth.com/2017/09/21/100-years-of-walter-munk-and-the-role-of-lunar-tides-in-ocean-circulation/

This was Munk’s original assertion:

“Our very tentative conclusions are that l) tidal dissipation plays a dominant role in pelagic mixing processes”

99. Magma says:

@ WHUT: I had the wrong year and meeting. It was February 24, 2016 at the AGU/ASLO/TOS OSM meeting in New Orleans. But it seems Munk has used the WWII analogy before, and why not? It’s a good one.

100. angech says:

“Global ocean tide loading charts of the radial displacement, the potential divided by g (gravity acceleration), and the gravity effect have been computed”
A snippet mentioning the fact that there are pumps acting on the water and more so at depth.
These provides an ongoing method mechanism for heating by pressure at depth to explain the failure of the deep ocean water under pressure and increasing cold to turn to ice?
It would appear that there are ongoing pumping forces due to the effect of gravity changes from both moon and sun on the column of water in the sea. These effects are greatest at the sea floor due to the friction present there.
Moving the goalposts so best to ignore this comment.

101. angech,
Tidal heating it quite small (something like 0.01W/m^2) and – as far as I’m aware – most of it is dissipated in shallow, not deep water. As has been explained to you on numerous occasions, it doesn’t freeze in the deep ocean because the conditions for the water to freeze will almost certainly never be met. Here, for example.

102. Dikran Marsupial says:

Angech wrote “Moving the goalposts so best to ignore this comment.”

At least angech is openly admitting that he is bullshitting, even if he can’t admit that his argument is incorrect.

103. angech says:

The geothermal flux will also add some energy to the deep ocean. thanks ATTP overlooked that.
DM, I am not as you so politely put it, bullshitting.
I have a deep interest as do you in this subject.
We disagree on outcome and sometimes on the application of science to outcome.
When I raise matters that conflict you are able to point out the errors, fine.
If you feel entitled to be rude, go ahead.
If you see me being rude here call me out.
Thanks.

104. angech,
Just to clear the air, I don’t think you’re rude and I do appreciate your reasonable tone. I also, however, understand Dikran’s frustration.

105. verytallguy says:

I do appreciate your reasonable tone

I’m not sure that being unreasonable in reasonable tones is a good thing. But anyway, one can note:

These provides an ongoing method mechanism for heating by pressure at depth

No, they do not. “Heating by pressure” is a one-off event as work is done on a parcel of water.

It cannot be “ongoing” unless the water is continuing to descend.

Beyond demonstrating their misunderstanding of thermodynamics, I have no idea what point Angech is trying to make.

106. It cannot be “ongoing” unless the water is continuing to descend.

Yes, but I was taking angech to be referring to tidal heating, which is ongoing. However, the total amount of energy is small (about 1020J per year) which is much smaller (about 100 times smaller) than the energy we accrue per year due to the anthropogenically-driven planetary energy imbalance. Also, as far as I’m aware, it is mainly dissipated (heats) shallow water, so isn’t really relevant for the deep ocean.

107. Since we’re discussing tidal energy, my understanding is that the total amount of energy we use (about $6 \times 10^{20}$ J per year) is about 10 times greater than the total amount of tidal energy.

108. Magma says:

@ ATTP: solid earth and ocean tides dissipate about 3-4 TW, so human use of energy is about 4 to 6 times greater than the tidal energy. Which is still a remarkable thing.

One of the regular, stupider AGW denial points is that humans couldn’t possibly affect something on the scale of the planetary climate. Considering we now shift more rock and soil than all natural processes, have changed the atmosphere more than any other process apart from the evolution of cyanobacteria and land plants, massive, million-year long flood basalt eruptions, and are credibly beginning the Earth’s sixth mass extinction event, this illustrates their failure of imagination and knowledge as well as anything else. Just little old Homo sapiens, all 7.5 billion of us.

109. Magma says:

*and* massive million year-long flood basalt eruptions

110. Dikran Marsupial says:

Angech, ignoring counter arguments and evading the consequences by blithely substituting a different argument (again without taking the time to determine whether It has any real validity) is rude and disrespectful of you interlocutor (it is basically saying you don’t take their arguments seriously). A reasonable tone is no substitute for reasonable behaviour, the problem is not that you are overtly rude (here at least, but I have seen your posts elsewhere) – the problem is that your approach to discussion is unreasonable in that you can’t accept being wrong, and you repeatedly make assertions of fact that are obviously wrong. This is highly disruptive in a discussion of science as it is difficult to allow such misinformation to go unanswered.

This has been pointed out to you before, politely and you have repeatedly ignored that as well, so perhaps you should expect a more plain-spoken approach.

111. Dikran Marsupial says:

Note that angech still hasn’t accepted that his old argument was wrong, or that his new “goalpost shift” argument was wrong, but has moved ontp geothermal flux, which was mentioned by VTG and myself much earlier in the thread, but apparently ignored by angech at the time.

112. Dikran Marsupial says:

I googled angech’s quote. I would be interested to hear from angech, in his own words, exactly what there is in that paper to support his contention that pressure stops the deep ocean from freezing. I couldn’t find anything.

113. Dikran Marsupial says:

The paper is here, FWIW. As far as I can see, the paper isn’t about tidal heating, in fact I didn’t notice any discussion of thermal issues (although I could have missed them as it is not my field and I only speed-read it). The paper seems to be about making corrections to tide data from satellite altimetry compensating for the slight deformations of the crust caused by the tides themselves.

114. Dikran,
Thanks, so it’s actually about “tide loading” which is how the ocean can deform the Earth’s surface. Here, for example,

Ocean tide loading is the deformation of the Earth due to the weight of the ocean tides. The water in the ocean tides moves back and forth and these mass redistributions cause periodic loading of the ocean bottom.

115. Magma says:

@ Dikran, ATTP

Personally, I think that wasting others’ time and taking up space with nonsense again and again is also a form of rudeness (or trolling). It’s sealioning, as other posters here have previously observed.

116. Dikran Marsupial says:

Yes, it seems a clear example of “making an argument without caring whether it is valid or not”, perhaps I should call it “Frankfurtery”? Picking an obscure paper and making me read it is a pretty good method of jötunn-ry, I suspect I took rather longer to understand it than it took to post.

117. Dikran Marsupial says:

BTW of course there is an ongoing “pumping” effect from the tides*, but not an ongoing compression. Obviously the water will be deeper at high tide, which will increase the pressure in the water column below (although an extra few meters isn’t going to increase the pressure greatly in the deep ocean, as it is only a small percentage increase). All things being otherwise equal, there should be some heating as a result. However, at low tide, the pressure will be lower than average, which would result in a slight cooling, so it seems hard to argue that there would be any long lasting effect from the pressure (rather than frictional heating from the motion).

* of course we don’t need a very complicated paper on tidal loading to know that, the Wikipedia page on tides is more than adequate to justify the idea of tides, if any were needed!

118. Regarding tidal mixing, this recent paper:

“In addition, pronounced changes in tidal energy dissipation occur in both the open ocean and in shelf seas, also altering the location of tidal mixing fronts. These changes have the potential to impact ocean mixing, and hence large-scale currents and climate patterns, and the contribution of shelf-sea to the global carbon cycle. The new results highlight the importance of considering changes in the tides in predictions of future climate and reconstructions of past climate phases such as the Last Interglacial.”
Wilmes, S.B., Green, J.A., Gomez, N., Rippeth, T.P. and Lau, H., Global Tidal Impacts of Large‐Scale Ice‐Sheet Collapses. 6 October 2017, Journal of Geophysical Research: Oceans.

119. angech says:

I would be interested to hear from angech, in his own words, exactly what there is in that paper to support his contention that pressure stops the deep ocean from freezing. I couldn’t find anything.

– Correct. That paper was more on the other gravitational pressures acting on the body of water rather than the body of water acting on itself through a simple gravity effect on a column.

DM I found this interesting paper Physical Properties of Seawater that does support the contention.
pordlabs.ucsd.edu/ltalley/sio210/DPO/TALLEY_9780750645522_chapter3.pdf
It talks about the lapse rate and the effect of pressure on temp giving a comparison of how temperature increases in the atmosphere with increasing pressure and how this effect is also present in the sea.
“the lapse rate for ideal gases can be derived from basic physical principles; in a dry atmosphere the lapse rate is approximately 9.8 C/km. The lapse rate in the ocean, about 0.1 to 0.2 C/km, is much smaller.
Potential Temperature ” Seawater is almost, but not quite, incompressible. A pressure increase causes a water parcel to compress slightly. This increases the temperature in the water parcel if it occurs without exchange of heat with the surrounding water (adiabatic compression]. adiabatic compression causes the temperature to increase.”
This temperature does not seem to be one that dissipates but is conditional on being at a certain depth [pressure].

120. angech says:

Magma, Sea lions are what is referred to in medicine as heart sink patients. Every time they come into the waiting room your heart sinks. Every time you give them an answer they find something else to complain about. If they come less often it is better but they still need to be treated.”

I will stop on this thread and will reduce my comments on future threads. All it needs sometimes is a heads up so thank you.

121. angech,
Yes, if you increase the pressure on some fluid then one would expect the temperature to go up. This is not really in dispute. What is being pointed out (and that you still seem to not have acknowledged) is that such a process cannot provide a continual source of energy.

122. gallopingcamel says:

“If pressure determined temperature, why are the deep oceans colder than the surface ?”

The oceans have an adiabatic lapse rate that depends on “g” but temperature rises with altitude because water is much less compressible than air. As one descends in the oceans temperature falls until the temperature of maximum density is reached (~4 degrees Centigrade).

This process is quite well understood as you will see here:
http://nptel.ac.in/courses/119102007/7

123. galloping,
As already pointed out, seawater with a salinity about 24.7 does not have a maximum density at 4oC; the density increases with decreasing temperatures for all temperatures above freezing.

124. FAO angech (last sentence only)

125. angech says:

gallopingcamel says: October 21, 2017 at 5:00 am
“As one descends in the oceans temperature falls until the temperature of maximum density is reached (~4 degrees Centigrade).”

This misunderstanding on the temperature and density of saline ocean water at depth needs to be cleared up [again] as multiple people have made these comments on a maximum density at approx 4C for the oceans or for a 4C temp at the bottom of the ocean.
ATTP and others have corrected it but it still appears. The statement is true for fresh water at 4C only. Slightly salty water also has a maximum density above freezing point.
Salt sea water on the other hand always has increasing density with decreasing temperature to the freezing point which may be below zero.
Hence the coldest ocean water is also the densest and is on the bottom of the sea. Temperatures at the bottom of the deep oceans can be as low as -2.8 C.

126. angech says:

ATTP. If you wish to remove the last paragraph that would be fine. I only wanted to clear up the 4C comment, not restart this thread when I had said I intended to stop

[Mod: done]