‘There is an important point that was missed in your article about the Stefan-Boltzmann equation. Applying the argument to the “greenhouse gas” theory is quite simple: there can be no “back radiation” from the colder atmosphere to the warmer earth’s surface. It violates the 2nd Law of Thermodynamics as it applies to radiative transfer…’
More following from Dr. Martin Hertzberg, a coauthor of “Slaying the Sky Dragon-Death of the Greenhouse Gas Theory”…
‘Consider two flat, parallel surfaces each with unit emissivity facing each other. One surface is maintained at a higher temperature, Th while the other surface is maintained at a lower temperature Tc . If the hotter surface were facing a complete void or surroundings at 0 K, the flux of radiant energy that it would emit and that the void would receive is sTh4.
‘Similarly, if the colder surface were facing a complete void or surroundings at 0 K, the flux of radiant energy that it would emit and that the void would receive is sTc4. But neither of the surfaces is facing a void: they are facing each other, and accordingly the net flux of radiant energy in the field between them is:
I (net) = s (Th4 – Tc4 ) ,
and is always from the hotter surface to the colder surface as required by the 2nd Law of Thermodynamics.
‘Nowhere in the radiation field between the two surfaces is the flux of radiant energy equal to what either of the surfaces would emit if they were facing a complete void at 0 K! Thus, the simple use of the Stefan-Boltzmann equation to characterize the emission from a source of radiation as though it depends only on the temperature of the source without considering the temperature of the surroundings that are receiving the radiation, is a misuse of the equation, and the notion that a colder source can transfer radiant energy to a warmer object involves not only a misuse of the Stefan-Boltzmann equation but also a violation of the 2nd Law.
‘The situation is analogous to a simple problem in mechanics. A 1 Kg mass is sitting on a frictionless table and is subjected to a force of 10 Newtons from left to right and simultaneously subjected to a force of 7 Newtons from right to left. Now you are free to calculate what the motion would be if only the 10 Newton force acted on the mass, or if you prefer, you can calculate what the motion would be if only the 7 Newton mass operated on it. But, of course, neither of those calculations describes the real motion, which is that of a 3 Newton force acting from left to right. There is no motion to the left from the weaker force.
‘Thus it should be quite clear that the simple use of the Stefan-Boltzmann equation as though it can characterize the radiant energy being transferred from a source to its surroundings without any reference to the conditions of the surroundings that are receiving that radiant energy, is a misuse of the equation.’
Dr. Martin Hertzberg coauthor of Slaying the Sky Dragon-Death of the Greenhouse Gas Theory
**************
Part 1 on the Equation: http://jennifermarohasy.com/blog/2011/02/a-note-on-the-stefan-boltzman-equation/
The Dragon book: http://slayingtheskydragon.com/
Apologies in advance: The equations inserted into the above texts appear to be displaying OK as posted – using internet explorer as my browser. But I have had problems before with mathematics in blogs displaying properly – so apologies in advance if they aren’t looking right.
Jennifer Marohasy BSc PhD is a critical thinker with expertise in the scientific method.
What incredible utter rubbish. If so it’s a Nobel prize.
Okay Luke why is it incredible rubbish and anyhow can’t any useless layabout win a Nobel these days?
I just hope Martin is available to answer such rude, stupid statements.
Yes luke, why is it rubbish? Think about it:
I (net) = s (Th4 – Tc4 ) ,
Isn’t this what the alarmists have been saying; that is, it is the net energy flow?
It’s been kicked to death over at Climate Etc….
FOR laypeople like me (and dare I say it Luke) Dr Martin Hertzberg has a post at WUWT http://wattsupwiththat.com/2011/01/24/commentary-hansen-draft-paper-paleoclimate-implications-for-human-made-climate-change/
I think Luke’s comment that ‘it’s been kicked to death’ … is far too simplistic
I mean even the warmists should be looking for truth .. is that not so … or is each side just looking to win the argument
On this specific point, Dr Curry is correct, and Dr Hertzberg is wrong. There is no 2nd Law violation for an individual atmospheric CO2 molecule to radiate an IR photon in any direction it jolly well pleases.
Poetic license aside, gas molecules in our atmosphere do not have consciousness. They cannot ‘sense’ relative warmth or relative coolness in any direction whatsoever. The frictionless-table analogy is a red herring. So, what’s really going on?
The medium-size Tc and Th objects both radiate in ALL directions. And yes, that includes our favorite bête noire, back-radiation. Surprise, surprise! In this case, the warmer of the two objects, which radiates with greater intensity, will warm the cooler one, as predicted by the 2nd Law.
My explanation, which happens to be the conventional one, is simpler. By Occam’s Razor (spelling?), the simpler explanation trumps the bells-and-whistles explanation.
Can Dr Hertzberg or anyone else describe a gedanken experiment that has the potential to falsify the simpler explanation? If so, has anyone actually gotten their hands dirty, and performed that experiment?
Part of the confusion stems from the term, “Greenhouse Effect”. In real greenhouses, the structural components goof up convection cells, as well as providing a small amount of ordinary insulation. These two garden-variety (pardon the pun) mechanisms are far more important than the CO2 concentrations in an actual greenhouse. Therefore I modestly propose that we change the name from “Greenhouse Effect” to “Larry Effect”. But do I have to go fly the way to Stockholm to collect my Nobel? 🙂
Chemists–yours truly included–understand the dynamic nature of some natural processes. Why can’t Dr Hertzberg wrap his brain around that concept? With respect to the Larry Effect, scientific fundamentalists are giving a bad name to AGW skepticism.
A parting thought: Warmists are not smart enough to be wrong 100% of the time. In the spirit of fairness, lets give the devil his due.
“Comment from: Larry Fields February 10th, 2011 at 6:38 pm
On this specific point, Dr Curry is correct, and Dr Hertzberg is wrong. There is no 2nd Law violation for an individual atmospheric CO2 molecule to radiate an IR photon in any direction it jolly well pleases.”
May I suggest that Maxwell-Boltzmann kinetic energy curves for gasses shows that Dr Curry has a point but the number of CO2 molecules with sufficient energy to radiate is vanishingly small. Also Perry’s Chemical Engineering Handbook shows that the emissivity of 100% pure CO2 at standard temperature and pressure is 0.05. Think how small the emissivity figure would be for CO2 at 395ppv would be at far lower temperatures and pressures.
I made this comment on cementafriend’s post on this topic and my comment was never answered
and I suppose my question is – is there back radiation or not – is there any consensus or weight of opinion
here’s my previous comment on the other post
Dr Roy Spencer has an interesting discussion on his blog
http://www.drroyspencer.com/2010/08/help-back-radiation-has-invaded-my-backyard/
He says (as I understand it) … Except for relatively rare special cases, the total amount of IR energy downwelling from the sky (Ed) will ALWAYS remain less than the amount upwelling from below and absorbed by the sky (Aa). As long as (1) the atmosphere has some transparency to IR radiation (which it does), and (2) the atmosphere is colder than the surface (which it is), then Ed will be less than Aa…even though they are usually close to one another, since temperatures are always adjusting to minimize IR flux divergences and convergences.
Then there’s this view http://claesjohnson.blogspot.com/2010/07/no-backradiation-no-radiative-forcing.html
Without atmospheric backradiation there is no radiative forcing. The very basis of the IPCC climate alarmism thus seems to lack physical rationale
I’m not competent to judge one way or the other but reading the discussion on Dr Curry’s blog was interesting (but difficult for a layman)
Val – Wattsup as source – pullease.
Val simple empirical experiments invalidate his position
and on philosophy
You need to read http://judithcurry.com/2010/12/04/education-versus-indoctrination/#comment-18468
This violation of the 2nd law is a bit of a red herring. Larry, there are plenty of thought experiments which vindicate what Martin is saying; luke has lots of them about lightbulbs but hasn’t figured it out yet; a good one was featured at SoD:
http://scienceofdoom.com/2010/07/26/do-trenberth-and-kiehl-understand-the-first-law-of-thermodynamics/
I attempted to point out the problem with the lightbulb and backradiation at this comment at July 30th, 11:16am:
“If we take SoD’s sphere and assume the light source puts out 100 units of radiation per unit of time and 1/2 of that 100 units is reradiated back into the inner sphere and 1/2 is conducted away then in the 2nd unit of time the source emits another 100 units which is combined with the 50 units from the 1st unit of time so that 150 units is available to be absorbed by the inner surface with 1/2 or 75 being reemitted and 75 being conducted away. This is, of course, a limiting sum geometric series:
Sn=a/1-r where a=1 and r=0.5; or 1/n^2 for n=1 to infinity is 2.
That is, the radiation available in the room will not double until infinity; the asymptotic aspect of this is, of course, what happens with additional CO2 in the atmosphere.”
Chris G, a superior troll, came in and missed the point and I gave up when Mark, a nasty type arrived.
The point is AGW backradiation, like luke’s mythical lightbulbs cannot keep heating its hotter energy source to a runnaway situation; people have pointed out that Zeno’s arrow is not applicable to the real world and that is where my analogy falls down; but like Chris G and Mark they miss the point that unlike Zeno’s arrow with my thought experiment there are 2 moving factors; the energy being backradiated and the energy leaving; their relationship is defined asymptotically so that the backradiation cannot heat the surface, in effect, beyond a stabilising level. In the real world CO2 has already done that so further increases of CO2 have no effect.
Luke I have my doubts about your simplistic reply
Of course you do Val – which proves Chris Colose’s point.
But moving right along dare I suggest the humble Osram IRC light bulb shows back radiation in action violating the crap out of the 2nd law – colder to hotter ! http://lightingpro.com.au/catalog/osram_irc_halogen_lamp.php look Mum – no hands.
In my note on the S_B equation I put that engineers determine practical solutions to problems. Engineers do not always care about the intimate details of the derivation of theory. If an empirical solution works that is accepted until it is found that the solution does not always apply or something more definite is found from actual measurement of results. As an engineer, certainly, I appreciate the 2nd law of thermodynamics. Never in all my measurements in furnaces and heat exchangers have I come across heat transfer from a cold substance to a hotter one nor the enhancement of heat flow from a hot substance to a cold one by the presence of the cold surface or substance.
Heat transfer by conduction is analogous to transfer of electrical energy and can be modelled by electrical circuits -voltage difference can represent temperature difference. The net heat flow and net current only go in one direction.
Possibly radiant heat flow in a vacuum can be represented by magnetic flux. It is known magnetic fields exist in space but I have not studied that. Maybe it is important for physicists to understand the theory so that they can keep getting funds to work on a new hypothesis. Here (http://tallbloke.wordpress.com/2011/02/09/ed-dowdye-light-bending-proposal/) is something about Einstein’s theory of relativity being falsified by actual measurement ie that is light is not bent in a vacuum but only by interaction in a Corona.
I make the point that the sun is not an ideal black body. Engineers correct the S-B equation with emissivity factors to give a good ESTIMATE (hopefully with better than 5% error) of actual heat transfer by radiation in situations of large temperature difference. It should be noted that making measurement based on the S-B equation applicable only to a black body radiating in a vacuum can not give an accurate measurement. I also make the point that radiation absorption by CO2 in the atmosphere makes an insignificant contribution to atmospheric and surface temperatures.
Good health and keep strong
Cementafriend
What Martin has shown is that the downwelling measured IR during the night cannot come from a colder radiating gas in the atmosphere, eg CO2 etc.
Therefore what is the source of the measured IR ?
Well cementsy – dat’s coz we’re not talking about conduction are we? You must have never measured the impact of a radiation shield then.
Louis – problem for Martin is that you can measure this supposedly “non-existent” IR? Oh dear. Louis disappears in a puff of empiricism. And has been discussed elsewhere – he’s also WRONG. So he ain’t shown squat.
Just another variation on the theme of trying to do something about the climate.
Here is John Christy at his best explaining why tackling CC is easier said than done.
In fact even building 1000 nuclear power stations in the USA would make only the smallest difference, but just about no difference at all.
Let’s hope we stop listening to that idiot Flannery heading up this new committee trying to soften us up to accept the nonsense we can really make a difference this time.
What is wrong with our apathetic Aussie people and at least some of our leaders that we can’t even calculate simple sums that would stop us wasting billions of $ for no return?
What a totally useless scam.
BTW a very good slide show, first class.
I’m with Luke on this. Jennifer you need some sort of peer review to cull out nonsense. This post is embarrassing for a blog of quality like yours. Next someone will be posting that jumpers can’t keep you warm in winter because jumpers are colder than your skin!
Actually the thermos flask is a better example – hotter on the inside than the outside by reradiating IR back – holding it doesn’t scald your hand even though the tea scalds your tongue.
Graham,
You know I have never been a big fan of peer-review because of course whether this post got through or not would have depended on who was chosen to undertake the review in particular whether I chose a theoretical physicists or a practical physicist.
And who said the science was settled? Who says we understand radiation?
And I didn’t find your rebuttal relevant.
Martin’s point is that heat always moves from a warmer to a cooler body? What is your opinion on this?
I think the Dragon is a huge waste of time and only gives AGW believers some new faux excuse to avoid dealing with the problems of global climate disruption.
AGW does not need a rewrite of physics to fail.
“Like conduction, thermal energy is in harmony with the second law of thermodynamics such that, in the absence of work, thermal energy is radiated spontaneously from higher temperature to lower temperature matter.” — Professor M. Quinn Brewster, University of Illinois: Thermal Radiative Transfer and Properties
This is what Dr Hertzberg is saying as well.
Any good physics textbook will describe heat as energy in transit due to a temperature difference, and will identify the direction of that transit as from a warmer to a cooler body (in accordance with the 2nd law). That textbook will then describe the 3 modes of heat transfer, meaning it is understood that radiative heat transfer is ALSO energy in transit due to a temperature difference, the direction of that transit being from a warmer to a cooler body. In short, conductive and radiative heat transfer follow the same rule: greater energizes lesser.
The failure to understand this can’t be due to stupidity — for the basics of heat transfer are easy enough to grasp — rather this failure seems more to do with attitude, an obstinate refusal to accept that a fact is a fact. The Second Law is a law, not a friendly suggestion, and radiant energy transfer conforms to that law. Whether it pleases one or not.
“Martin’s point is that heat always moves from a warmer to a cooler body?”
His point is a complete misinterpretation of basic physics. And simple empirical experiments demonstrate that.
Something rejected by peer review should sound warning bells to check more thoroughly at least. As soon as you start fantasising you’re Galileo you’re deluded.
Jen – explain the Osram IRC light bulb !!! a challenge
In response to Grahams post, jennifer February 11th, 2011 at 12:22 am wrote:
“Martin’s point is that heat always moves from a warmer to a cooler body?”
Actually, Martin’s main point is more specific than that. Essentially, he is claiming that IR radiation can only move from a warmer body to a cooler body, and not the other way around. Unfortunately, there’s ZERO evidence to support Martin’s magical thinking. Here’s the larger dynamic picture.
Process A: The warmer body radiates towards the cooler body. In that process, the warmer body cools off a bit, and the cooler body warms up a bit. So far, so good.
Process B: The cooler body radiates towards the warmer body. In the process of losing a SINGLE IR photon, the cooler body cools off a bit. And in the process of receiving that SINGLE photon, the warmer body warms up a bit; i.e. the average temperature of that body increases slightly. Counter-intuitive? Maybe. Please continue reading.
The net result. Since the warmer body radiates with greater intensity, Process A dominates in the long run, and will continue to dominate, until the two bodies eventually reach equal temperatures, and attain a localized thermal equilibrium, in which the magnitude of A equals the magnitude of B.
No 2nd Law breach here! And no fundamentalist hallucinations about that law.
In the physical sciences, there are many graduate students who can jump through the necessary academic hoops, because of their hard work; because of their communication skills; because of their pattern-recognition skills; and because of their ability to memorize formulas, WITHOUT NECESSARILY UNDERSTANDING THEIR ESSENCE. After acquiring the initials after their names, they go on to function adequately in routine jobs, provided that they have sufficient supervision. My guess is that back in the day, Martin fell into this category.
Sorry, Martin. Bluster is no substitute for analysis.
All people are created equal. But contrary to Postmodernist doctrine, all ideas are NOT created equal. Some are essentially correct; some are partially correct; some are flat-out wrong; and others are not even wrong!
Thanks Larry.
And further, what is radiation? What are its fundamental characteristics? What do we know about it and what don’t we know about it?
Thanks Luke, but unlike Larry, you have not provided an opinion on the key point of contention:
“Martin’s point is that heat always moves from a warmer to a cooler body”.
Your thoughts?
Simple Jen – that’s conduction not NET radiation.
The Osram IRC bulb uses an infrared reflective coating to re-radiate back to the filament to achieve the same light output as an uncoated bulb for less electricity. According to you this can’t happen? Colder glass can’t warm the hotter filament.
See also Rabett’s tin foil experiment – why does the bulb get so hot?
http://rabett.blogspot.com/2008/09/light-dawns-there-are-styles-in-science.html
or radiation shields in furnaces
And Jen – you might ponder what all these people measuring SW and LW up and down with net radiometers are actually doing. Just think of all those papers on energy balances and irrigation scheduling water balances that have been developed and validated are now somehow wrong and replaced with a mysterious force?
See What down wave longwave measurements Exist? at http://scienceofdoom.com/2010/07/17/the-amazing-case-of-back-radiation/
And http://scienceofdoom.com/2010/07/31/the-amazing-case-of-back-radiation-part-three/ see Figs 1 and 2 – please explain why these energy balance components (measured) are wrong?
Jen you have developed a new physics – it’s your job to explain it. This is revolutionary stuff you’re proposing here ! Needs a BIG explanation.
And I thought you loved empiricism?
Your considered view in light of this empirical evidence ?
NET radiation – not conduction.
luke
“crap out of the 2nd law – colder to hotter ”
Sorry, keeping a body from cooling down is NOT the same as a colder body warming a warmer one!
Luke,
““Martin’s point is that heat always moves from a warmer to a cooler body?”
His point is a complete misinterpretation of basic physics. And simple empirical experiments demonstrate that.
Something rejected by peer review should sound warning bells to check more thoroughly at least. As soon as you start fantasising you’re Galileo you’re deluded.
Jen – explain the Osram IRC light bulb !!! a challenge”
So Luke, you know what a heat pump is?? It actually moves energy from a colder area to a hotter area by converting energy through work. Hopefully even you understand that. It really is part of the conservation of energy and thermodynamics. Without the expenditure of work the simple statement that heat always moves from warm to cool is, to put it simply, correct. This may be a net flow but that in no way invalidates the statement.
Looked at your neat lightbulb. It appears to simply reduce heat losses keeping the filament warmer than otherwise. Nothing very exciting there as keeping the filament warmer allows less energy for the equivalent light output. Why is that important in this lamp? Because they use a gas with a heavy molecule to reduce the filament boiling away. This heavier gas would increase the conductivity and losses otherwise. Your lamp is a series of trade-offs!!
I would suggest there is a reason they do not use CO2 in the bulb, but, you would miss the point!! (snicker)
There seems to be a lot of misunderstandings and postings at cross purposes.
I would just like to get the following cleared up:
1. Do we all have the same understanding of what radiation is? What is radiation?
2. Does heat always move from the warmer to the cooler when it comes to radiation?
3. How much empirical evidence is there for the following from Larry:
“Process B: The cooler body radiates towards the warmer body. In the process of losing a SINGLE IR photon, the cooler body cools off a bit. And in the process of receiving that SINGLE photon, the warmer body warms up a bit; i.e. the average temperature of that body increases slightly.” How does the cooler body radiate towards the warmer?
check out what scientists have been telling us over the years
http://butnowyouknow.wordpress.com/those-who-fail-to-learn-from-history/climate-change-timeline/
Kuknkat – nope on the bulb – read it again – and that is ONE example. And it doesn’t “appear to” – it does !
“A reduction in losses due to thermal radiation (IRC):
Special bulb geometry and a sophisticated coating on the bulb ensure that the thermal (infrared) radiation is reflected and the heat emitted from the filament is reflected back to the filament. As a result the filament is heated further. This means that less electrical energy has to be supplied to the filament”
You could of course use Eli’s tin foil regular light bulb
And GE do it too …. http://energyefficientbulb.net/100-watt-halogen-par38-light-bulb-ge-hir-par-lamp-25-degree-narrow-flood-beam-spread-100parhirfl25/
net is NET
From the book on Thermodynamics by Engel and Reid, page 83:
“The second law of the thermodynamics has been tested many times by inventors who have claimed the discovery of a motor that has an efficiency of 100%. Such requests have NEVER been validated.”
“It is impossible for a system to experience a cyclical process which effect is the flow of heat towards the system coming from a warm reservoir and the system renders an equivalent amount of work on the surroundings.”
“For a system which experiences a cyclical process, it is impossible that the only effect is the heat flow towards the system coming from hot reservoir and the flow of an equivalent amount of heat outside the system, towards a warm reservoir.”
@the advocates of the violation of the second law of thermodynamics:
The radiant energy is emitted to all directions, but the hot system cannot simply absorb the originating photons from a colder system because the warmer system photons have an energy density microstate higher than the colder system and, according to the definitions above, the absorption of radiating energy is an irreversible process. The second law supports what I am saying:
“The energy from a set of systems is ALWAYS dispersed or diffused from the systems with a higher number of occupied energy microstates towards the systems with a higher number of available energy microstates.”
In other words, the systems with a lower number of microstates ALWAYS emit the energy towards the systems with a higher number of microstates.
Put your violation to the second law in basic school numbers:
We have three systems; one of them has 8 unavailable microstates and 2 available microstates. The second one has 2 unavailable microstates and 8 available microstates. The last one has 10 available microstates. No primary source of energy at this moment. The trend in your nature, I mean your imaginary nature, is that the system with more unavailable microstates emit photons towards the systems with less unavailable microstates (we are talking on radiant energy, OK?). The system with 2 unavailable microstates will only have an option on emitting photons, and it is towards the system with all its microstates available; however, you say that it can emit towards the system with its almost all unavailable microstates. Well, the first system emits one photon and its situation is now, following your logics, of having 3 available microstates, toward which the second system could emit one photon. Well… The first system continues having 8 unavailable microstates, not 9 neither 10. The second system will have, momentarily, 3 unavailable microstates, but it will emit one photon and it will have, again, 2 available microstates. Now, the second system has another option, to send one photon towards the first system and another photon towards the third system with all of its microstates available. It emits and its situation is now 0 (zero)… ZERO… unavailable microstates; so it can absorb the eight photons that the first system has! Oh! But we have the first system which can emit photons from each one of its unavailable microstates!!! Wow! That doesn’t happen in nature.
Now put it in words: The warmer system has eight unavailable microstates which are occupied by energy. The colder system has eight available microstates which can be occupied by the energy emitted by the warmer system. The void system has ten available microstates toward which both, the first system and the second one can emit their energy.
NOW ANSWER TWO QUESTIONS:
1. Towards where the second law of thermodynamics says the energy will flow? Answer it by your usual fashion, without a primary source of energy.
2. How much time the energy in the two unavailable microstates of the second system will take to be dispersed towards the two available microstates of the first system, and how much time it will take to be dispersed towards the eight available microstates of the same second system?
What the advocates of the violation of the second law of thermodynamics are saying is comparable to those claims on perpetual motion machines, which have never been constructed because it is IMPOSSIBLE. We have never seen, either, a low energy photon being absorbed by an atom or molecule in a high energy state and that those atoms or molecules have acquired, or jumped to, a higher energy state. What is more, we have NEVER seen a photon or measured its position and microstate at the same time. Those assertions are pure pseudoscience; imagination and no more. We would need no more the Sun… 🙂
Just think in this: you are facing the monitor of your computer. The plasma screen, or whatever it could be your screen, is emitting radiation towards you. Open a picture with contrasting colors, white and black, for example. The white zones are emitting a higher amount of wave-photons and particle-photons towards your eyes. Your retinas are absorbing those photons, reflecting an amount of them and emitting photons towards the screen. Tell me… Are your Superman eyes heating up the screen? But continue with the experiment, you well seated on your chair. Look at the dark areas… Are your Superman vision making those dark areas emit more photons than before you looked at them?
Everything in this universe obeys the Second Law of Thermodynamics, and, believe it or not, also climate does.
luke
“As a result the filament is heated further”
Sorry again, but either you or the writer of that blurb doesn’t understand what is happening.
IF, as you say “As a result the filament is heated further” were true, then by logic, the input current could be slowly reduced and the re-radiated energy completely or at least mostly taking over the heating of the filament.
You know that is not possible.
The filament is NOT heated further, it’s just kept from cooling too far down, by reducing the IR radiation through the glass envelope.
Not the same thing as heating it at all, it’s just like a “blanket”.
Theorising about light bulbs, tin foil etc is generally pointless because no analogies compare to our chaotic, rotational, turbulent atmosphere.
Net heat moves from warm to cooler [but is reduced] just as the net force above was reduced from 10 to 3 nm.
However that is not the real world and the signal over the last 150 years is hard to find.
The real questions are:
Is there a problem?
What is the cost/benefit of impoverishing people to achieve anything?
What IS achievable?
And shouldn’t we concentrate on the bigger problems?
Spangled, Radiation, what it is, and how it transmits energy, is central to AGW. But how much do we know about it? What is a microstate? I am keen to try and understand how Graham and Luke perceive and understand radiation as a phenomena given there strident objections to this post. Larry has provided his own explaination. Do they support the concepts as explained by Larry – who appears to be on their side?
To address Jennifer’s question, no, I’d say it’s obvious that everyone is not agreed. There is radiation, and then there is radiative HEAT transfer. Radiation can be regarded as an EM field that surrounds objects at any temperature. But HEAT is only transferred when one body’s temperature is higher than another’s. Distance is also a factor, of course, due to the inverse square of light propagation: The sun, for instance, may be 5775 K, but its radiation cannot heat the earth to that temperature. The essential point to my mind, however, is that just as there’s no evidence that a cold body’s coldness “seeps in” to a warmer body via conductive heat transfer, there’s no evidence that a cold body’s radiation heats a warmer body either. Rather, the direction of heat transfer is one-way alone, from warm to cool. This “net transfer” business is just verbalistic camouflage.
The premise of greenhouse theory is that two equal and opposing flows of energy ADD (rather than cancel), such that 240 W/m² going up and 240 W/m² going down will generate 480 W/m² (but only on the emitting surface!). Since such a notion is childish and reprehensible, the same must be said for “climate science” too. Our civilization’s present climate alarm is based on a false and stupid premise, embarrassing as that will prove to be. Future generations will laugh at us.
Johnathon – a new equilibrium is reached with the reflective coating. There is no runaway feedback.
So you have the same filament temperature (and therefore light output) as normal bulb but for less energy input. The loss rate is reduced.
Johnathon – tell us why Eli’s bulb got so hot? Pls don’t tell me it’s insulation.
Spanglers – irrelevant to the thread. And given the cost of floods, droughts, infrastructure, and storms …. errr “no”. Who’s been impoverished – you’ve never had it so good.
Jen – I don’t object to your post. If it’s good enough for scienceofdoom and Judith Curry at Climate Etc – surely we mere dabblers can have a crack too.
These objections have been raised by sceptics so let’s talk about it.
That we may have “stong” views is another matter.
Prove the concept wrong and I then am perplexed what all these people doing energy balance experiments are measuring? What are these devices measuring? http://www.geneq.com/catalog/en/net_radiometer_nr_lite.htm
Jen, so true. Another head on the monster.
Luke, “Who’s been impoverished – you’ve never had it so good.”
That’s exactly my point and we should be using our present position to sort out the real problems.
BTW, your darling peer review seems to be smelling a bit “Schmidt-house” of late:
http://wattsupwiththat.com/2011/02/10/reviewer-a-responds/#more-33691
luke
I missed the thread on Eli’s bulb, but what I can gather from your question, despite you asking not to refer to “insulation”, if you coat a body that is constantly heated from the inside and prevent said heat to escape, why would YOU say it is getting hot? Not only that, but aluminium foil is a good reflector too, so you have a double whammy.
If you leave the “insulation” off of a hot water cylinder, it will not only take a lot more energy to heat it up to a certain temp. but it will also cool down faster than otherwise.
Common sense I thought
But what this has to do with anything?
Basically, I’m simply querying the claim of “Heating” against the term “preventing cooling”, that’s all, but it’s a significant difference I think.
Graham Young (10 Feb) mentioned the thermos flask as a good example of re-radiation – ” hotter on the inside than the outside by re-radiating IR back”. Perhaps the important issue here is that the temperature within the thermos flask does not get any warmer because of the “back radiation”; it may retain its existing heat for a time but will eventually cool.
Johnathon
http://rabett.blogspot.com/2008/09/light-dawns-there-are-styles-in-science.html
“But what this has to do with anything” – well 2nd law sceptic types say this can’t happen !
The heat escapes but the bulb surface sets a new equilibrium 160 C goes to 300 C when wrapped. Aluminium foil is a terrific conductor. It’s not an insulation effect.
And so if you complain about the foil the last comment refers you to IRC bulbs !
So doesn’t the existence of a “greenhouse effect” also simply set a new equilibrium and so the Earth is warmer than it would be without an atmosphere.
No, Luke… It is colder than it would be without an atmosphere. Without an atmosphere the Earth’s surface temperature would be 389.02 K, at its current distance from the Sun and its surface total absorptivity power. 🙂
Regarding the light bulb, it is hot because it has a primary source of energy… electricity.
luke
“Aluminium foil is a terrific conductor. It’s not an insulation effect.”
Tell that to K Rudd, the gov., the insulation industry, and see how far you go?
Never visited a construction site (specially domestic) lately have you?
Al foil is also a terrific “reflector” too Luke!
Well Johnathan – how does it actually “insulate?” in Kevin’s ceiling? Another example.
Gee Nasif …even at night too …. hmmmm
Luke
I knew from old, that it’s no point to argue facts with you, but I tried anyway.
If you say Al-foil is not an insulator you will have to take it up with someone in the industry.
If they were selling something under false pretences, then the families of the poor lads, who
were installing the stuff and died in the process, would have even more reason to sue!
All I’m saying, that used differently it can be a good conductor or a good insulator.
Many other substances display different properties under different situations, using examples in one situation to claim properties in an other is deceitful and fraudulent.
Oh Spangled One.
Thanks for the link to yet another the drama over the failure of Peer Review
It got added to my ever growing list of such links, on what an absolute crock of nonsense PR is.
Only the weak kneed bumbling ninnies that abound in climataria woud be that useless and unprofessional in their own work to tolerate such a medieval method of evaluation and ranking –undertaken using an enormous amount of public funds.
…and to think that the outcome of this idiot process is supposed to give everyone–governments and tax payers—confidence that the science has been rigorous and relevant.
…..pull the other one.
On the basis of the way PR doesnt work Mr Hertzberg is probably just as right as anyone else.
Comment from: jennifer February 11th, 2011 at 9:34 am
“I would just like to get the following cleared up:
1. Do we all have the same understanding of what radiation is? What is radiation?
2. Does heat always move from the warmer to the cooler when it comes to radiation?
3. How much empirical evidence is there for the following from Larry:
‘Process B: The cooler body radiates towards the warmer body. In the process of losing a SINGLE IR photon, the cooler body cools off a bit. And in the process of receiving that SINGLE photon, the warmer body warms up a bit; i.e. the average temperature of that body increases slightly.’ How does the cooler body radiate towards the warmer?”
1. That is partly a scientific question, and partly a philosophical question. Here’s a well-known piece of doggerel that emphasizes operational definitions, overstates the scientific aspect of the question, and pooh-poohs the philosophical aspect.
The man behind the microscope,
Has this advice for you.
Don’t ask what it is.
Just ask:
What does it do?
I hope that that helps a bit. Sorry, I don’t have a good answer for the philosophical part of your question.
2. In the long term, yes. In the short term–and especially on a microscopic level–no. During a few extremely short intervals, Maxwell’s Demons do gain the upper hand, but not often enough–or long enough–to exploit. Thermodynamics is macroscopic. On very small scales–and during short time intervals–Quantum Mechanics trumps Thermo.
Trivial example: In a temporal sense, radioactive emissions are non-uniform. That’s why Geiger-Counter time-interval measurements between radioactive decays of a small pitchblende sample can be useful as a generator of random numbers for computer simulations of theoretical models in physics.
3. How does it work? If you’ll pardon the anthropomorphism, excited CO2 molecules utilize a shotgun strategy: They radiate in all directions, indiscriminately. And the predictive power of my dynamic explanation is at least as good as Martin’s static, flowery, ‘New Age’ explanation.
Empirical evidence for Process B? How about evidence for Martin’s hand-waving? My explanation is simpler. According to Occam’s Razor, the burden of evidence falls upon the advocate of the more complex explanation.
Suppose that someone devises and performs an experiment that falsifies the Null Hypothesis, the mainstream Process A/Process B explanation, and provides physical evidence that CO2 and other gas-phase molecules have rudimentary consciousness, sufficient to detect and respond–in terms of their IR photon emissions–to warm and cool regions surrounding them. Then Psychic Larry predicts that two things will happen. First, that person will receive an instant Nobel Prize in Physics. Then he’ll be burned at the stake–in a professional sense. That’s what happened to heretic Leontieff (spelling?) after he received the Nobel Prize in Economic Science in 1973.
The heresy was the application of Input-Output Analysis to Macroeconomic forecasting. But Leontieff consistently got it right, and most of the big-name Macroeconomics mavens of the time got it wrong. And that irritated the hell out of them. Like AGW, Macroeconomics, even now, is a thinly-veiled religion, rather than a legitimate scientific discipline. But I don’t want to get too far afield.
BTW, my source is personal communication with the late economic policy wonk and heretic exemplar, Glenn Burress, who was quite accurate in his forecasts for the 1970s. He even predicted the Oil Shock of 1979.
@Larry…
You say:
“Thermodynamics is macroscopic. On very small scales–and during short time intervals–Quantum Mechanics trumps Thermo.”
My questions to you:
1. Thermodynamic potential is scalar or vectorial?
2. Internal energy is macroscopic or microscopic?
3. Energy levels are macroscopic or microscopic?
Please, answer these questions.
@Luke… Hi 🙂
Johnathon does aluminium insulation “insulate” like rockwool, batts, or cellulose – or is it reflecting IR
As I found on the net http://ezinearticles.com/?Radian-Barrier,-Foil-Insulation—Reflection-on-Reflective-Insulation&id=3605608
“You can test this by trying a little experiment. First, put your palm 1-2″ close to a standard electric light bulb and feel the heat. Try again, with some cotton wool between the lamp and your hand. You will feel better, but in only a few minutes heat will penetrate through the wool and you’ll still get hot, even though you now have an insulation layer.
Now, place a 4×4″ piece of household aluminum foil between the lamp and your hand (just make sure that the foil does not touch your hand) – and you will feel immediate relief. A little breeze to remove air between your hand and the foil (blow gently) and this will give you a perfect imitation of the beach umbrella effect. That’s exactly the way a radiant barrier or foil insulation works.”
Again – the point !
While appreciating Nasif, Alan and Larry’s comments I think a basic distinction needs to be established:
does a colder source radiatively heat a warmer source at all
or
does the colder source merely slow the radiative cooling of the warmer source?
Jo Nova has a post up about the appropriateness of app Prof Flannery
I’ve left this comment
I’m afraid the Govt and the Climate Change Commission with Flannery as the Commissioner have turned into a propoganda organisation
I’ve lived in a Communistic country and quite frankly the current media with a few exceptions are a propoganda machine
What hope do the populace have fed with the AGW propoganda through the ABC (publicly funded) and other stations
It’s a bit sad when the publically funded broadcaster in a democratic country simply follows the Govt line (or is it a matter of group think)
and where’s journalistic ethics (particularly investigative) end up in all this
At the foot of the dungheap – sad isn’t it
http://joannenova.com.au/2011/02/do-you-want-a-carbon-tax-poll-on-today-at-the-age/#comments
Agree-ers and non agree-ers visit and leave a comment
(I understand the Prof is receiving $185,000 pa salary)
and the sad point is what happened to the national interest
Comment from: cohenite February 11th, 2011 at 5:20 pm
“does a colder source radiatively heat a warmer source at all
or
does the colder source merely slow the radiative cooling of the warmer source?”
Good question! I’ll interpret it to mean that there are only two relevant objects in the system: W the warmer source, and C the colder source; and that the entire background is appreciably colder than C.
The extremely short-term answer to your question is: Both of the above. Why? Because in this extremely limited time-frame, we must consider weird albeit small quantum effects that would appear to run counter to the 2nd Law if they were long-term effects. I’ve chosen to use the descriptive term “Maxwell’s Demons” (which may be an imprecise use the term, as it is normally used).
The long-term answer is your second choice:
the colder source slowing down the radiative cooling of the warmer source.
Why? To Rephrase and summarize some of my earlier points, C is an imperfect heat sink. (Moreover the dominant quantum effects swamp out the paradoxical ones in the long term.)
By the way, your question suggests an elegant experiment that has the potential to put the kibosh on Martin’s conjecture. If there is no ‘back-radiation’, then the cooling rate of W (until localized thermal equilibrium is reached) will be the same, with or without C. Thanks.
Any takers for the Cohenite Experiment?
Nasif @5:02 -mate go easy on us – we’re only dumb Aussies. Might easy if you tell us the answers instead of asking to describe the universe and give two examples.
Comment from: Luke February 11th, 2011 at 6:29 pm
“Nasif @5:02 -mate go easy on us – we’re only dumb Aussies. Might easy if you tell us the answers instead of asking to describe the universe and give two examples.”
The answer is 42. 🙂
@Larry F
Slowing down the cooling rate of W does not make W warmer. That’s where the greenhouse theory fails thermodynamics.
If I understand correctly, CO2 reflects IR radiation from the earth’s surface?
And radiation is the same as reflection, ie if Lukes tin foil hat reflects the IR radiation from his giant brain, that reflection is analogous to the down welling IR radiation from atmospheric CO2?
Comment from: Paul Williams February 11th, 2011 at 7:05 pm
“If I understand correctly, CO2 reflects IR radiation from the earth’s surface?
And radiation is the same as reflection, ie if Lukes tin foil hat reflects the IR radiation from his giant brain, that reflection is analogous to the down welling IR radiation from atmospheric CO2?”
That’s close to the mark. CO2 molecules (and especially gas-phase H2O molecules) in our atmosphere absorb the IR radiation coming up from the Earth, and then the re-emit IR in ALL directions, including downwards. However a gigantic tinfoil hat for the entire planet would be more efficient at keeping he heat in. 🙂
Guys please; in this discussion your source must be the sun and your cold must be outer space. As far as Earth is concerned its only a spec that gets in the way and it’s atmosphere is nothing more than a flimsy filter.
Any idea that a single molecule of gas is acting like a black body with respect to earth is nonsense when we consider what happens while standing naked under a battery of IXL Tastic lamps in the bathroom. Even close up a little bit of air and vapor in between is hardly relevant in terms of hot or cold bodies.
One could ask how we screen our cold body? Getting dressed will do.
When Jen asks what is radiation, I ask what is moonlight?
One last wisecrack before bed.
Radiation is something you can hang a message on if you are clever, but don’t expect to touch it as it goes
Luke,
You scribble “Louis – problem for Martin is that you can measure this supposedly “non-existent” IR? Oh dear. Louis disappears in a puff of empiricism. And has been discussed elsewhere – he’s also WRONG. So he ain’t shown squat.”
Wrong.
No one is denying the existence of downwelling IR.
gav, you sure you haven’t been putting twisty bulbs in your IXL Tastic? You need some AGW.
Nasif Nahle has at some idea of heat transfer see here http://www.biocab.org/Heat_Transfer.html
I have seen in one paper on GCMs (general circulation models) a mention of Reynolds number but no mention of Prandtl or Nusselt or Grashof numbers. On one blog I mentioned to Gavin Schmidt (CR) the Schmidt number (viscosity/density/thermal conductivity) but he retreated at that point.
Nasif’s explanation of radiant heat transfer fits in with that of Prof Claes Johnson here http://claesjohnson.blogspot.com/search/label/myth%20of%20backradiation and here http://www.csc.kth.se/~cgjoh/blackbodyslayer.pdf . There appears to be increasing doubt about the statistical quantum mechanics in favour of wave theory. I am interested in various theories. Claes Johnson could have part of the answer. Another possiblity is that some in coming waves of electromagnetic energy to a warm body are just cancelled by the stronger outgoing waves. That settles both the 2nd law of thermodynamics (heat always flowing from hot to cold and never the reverse) and the fact that a receiver which is at temperature higher than absolute zero reduces the heat transfer in comparison to a black body receiver at absolute zero.
Some believers in AGW like to show themselves as knowledgible but it is very apparent that they the have little understanding of the engineering subjects of thermodynamics, heat (and mass) transfer, and fluid dynamics which are all important in assessing the complexity of the atmosphere, climate and weather.
I repeat again a cold body can not increase the heat flux from the hot body in comparison to what would have occurred if the hot body was radiating to ideal black body space at absolute zero temperature.
I also repeat that the trace CO2 in the atmosphere due to its small emissivity and to the minute amount present has an insignificant (repeat insignificant) effect on atmospheric temperature. This can be determined from equations resulting from experimental work carried out in large spaces with combustion gases. This is in keeping with measured information (eg icecores) which show that temperature leads CO2 or that atmospheric temperature varies independently of CO2.
I think Cementafriend touches on an important detail: No one really knows WHY heat always moves spontaneously to a lower temperature body… it just seems to be part of nature’s built-in software. But this, the 2nd Law, has been repeatedly tested by experiment, and all we can say with assurance is THAT heat always moves spontaneously to a lower temperature body, whether that body is in contact or at a distance.
As I say, one either accepts this or disputes this. But nature doesn’t care.
Larry Fields, the ad hominem guy, claims that his interactive heating approach — where less contributes to more and more contributes to less until both parties have the same — is simpler. But it seems to me that clues to the 2nd Law’s true behavior are all around us. Hertzberg mentions one example. Also, when two different gas pressures are separated by a membrane, the direction of force is toward the lower pressure chamber. Similarly, electricity will only flow when a lower potential is presented. Like it or not, explain it or not, accept it or not, there are forces of “equalization” in nature, and the way heat flows is one instance of this force.
Alan,
As far as I’m concerned, our little ‘debate’ is not about the truth of the 2nd Law; it’s about Martin’s misunderstanding and gross misrepresentation of it. Go ahead and make my day, if you’re feeling lucky. Get your hands dirty, and do the Cohenite Experiment, as described in the following post:
Comment from: Larry Fields February 11th, 2011 at 6:21 pm
Get it published in a peer-reviewed journal. Then report back to us if you dare.
from Martin Hertzberg
RESPONSE COMMENT
1. The Osram light bulb involves reflection only. The case I described involves two black-bodies. Black bodies have zero reflectance. This prevalent confusion among advocates of the greenhouse gas theory between emission and reflection is discussed in detail by Gerlich et al.
2. Nasif Nahle has responded quite incisively to Field’s comment by explaining how the distribution of energy levels constrain the system to transfer photons only from the hotter object to the colder one.
3. Fields argues that the hotter surface emits photons and cools, while the photons absorbed by the colder surface heats it until both surfaces reach the same temperature. For the record, the case I considered maintained both surfaces at a constant temperature regardless of the radiativie transfer involved.
Also, for the record, I don’t respond to the kind of ad hominem slurs contained in the last paragraph of Field’s comment. But I find it gratifying when an adversary in an argument, instead of citing the facts or the data, resorts to such slurs: It can only mean that I am winning the argument.
4 I recently had occasion to refer to an earlier publication of mine ( K. L. Cashdollar and M. Hertzberg, “Infrared Temperature Measurements of Gas and Dust Explosions”, Temperature, Its Measurement and Control in Science and Industry, Vol 5, 1982, American Institute of Physics, pp.453-463). In re-reading it, I realized that it contains the simplest description of the 2nd Law as it applies to radiative energy transfer. It is the well known practical example of the law: the Sodium D-line reversal method for measuring flame temperatures. That “line reversal” method has been used to measure flame temperatures for about a century. Here is our description of the method from the above paper:
“For flames or explosions, a more convenient means for measuring temperature involves radiation methods. For very high temperatures or for rapidly changing, non-steady state systems,
radiation methods are the only ones readily available. The radiation method most used in the past for normal gas flames or burners in steady-state is the “line reversal” method. In its ideal
form, the line reversal method uses a black body source whose radiance is viewed through the burned gases of the flame. The background blackbody radiance may be viewed in any region of
the spectrum where there is measurable absorption and emission from the flame. If the energy level distribution associated with the absorbing and emitting flame specie in thermal equilibrium
with the flame temperature, and if the blackbody source is at that same temperature, then the spectral radiation field within the flame is in equilibrium with the radiation field traversing through
it from the black body. In that equilibrium state, flame radiance and blackbody radiance become indistinguishable from one another. If the flame in the foreground is hotter than the blackbody
source in the background, then the flame appears brighter than the source because more radiation is emitted from the species upper energy level than is absorbed by the species lower energy
level. If the flame is cooler than the source, then the flame appears darker than the blackbody source because the lower energy level absorbs more radiation than is emitted from the upper
level. It is only when flame and source temperature are equal that the flame brightness in the foreground matches the source brightness in the background. This line reversal temperature
measurement is independent of the actual value of the flame’s absorptivity-emissivity, as long as the flame is not completely transparent in the chosen wavelength range. The method usually
used to assure a measurable interaction between the two radiation fields is to seed the flame with a sodium salt and to view the spectral radiance of the sodium D-lines at 589 nm. In the
traditional method, the spectrum of the flame and a tungsten ribbon lamp are observed visually. The lamp intensity is varied until the Na D-lines disappear against the lamp continuum. The lines
are then at the same intensity as the continuum. The flame temperature is calculated from the known temperature of the ribbon lamp, corrected for the emissivity of the tungsten.”
And there it is again, the 2nd Law of Thermodynamics in all its practical glory.
That ends my comment. Thank you for your consideration.
Marty Hertzberg
What’s the difference between a reflected photon and an emitted one?
Why isn’t this revolution published? I find it utterly incredible that something so important is not followed through into the serious literature. Otherwise frankly it will never see the light of day.
Thermodynamics does not apply to quantum scale interactions so there is no violation of the 2nd law.
At the thermodynamic scale the greenhouse effect acts as an radiative insulator, reducing the outward flow of energy by a maximum of 50% when 100% of the outward flowing photons are intercepted. This also means that any change in the inward energy will change the net greenhouse effect.
I am yet to see the greenhouse effect correctly describe as a amplification function of temp related to the inward energy flow. It always gets described as an independent force which it is clearly not
Hi guys, it’s been a while.
With all due respect to those of you whom I do in fact respect (including Larry), but i think Larry’s right. Reading through all of the responses so far there has been a tendency to get way too complex.
I f one CO2 molecule in the colder upper atmosphere absorbs an IR photon it will become excited(get warmer), it may then re-emit a photon in any direction but with a statistical probability a bit less than half in the downward direction. That photon may then encounter another CO2 molecule in the warmer lower atmosphere that is in the unexcited state whereupon said CO2 then becomes excited (gets warmed). This process will/may occur irrespective of the net ‘warmness’ or ‘coldness’ of each layer. Therefore the 2nd law is not relevant in this situation and it becomes an equilibrium situation.
So, to the question; can a colder body heat up a warmer body?
Consider the possible improbability that all of the excited CO2’s in a cold layer emitted IR at the same instant, nearly half would go in the general direction of the warm layer. Then if by chance there was a pause in the emission of IR from the warm layer, then there would indeed be a net warming of the ‘warm’ layer by the colder layer, therefore the answer to that question in this instance is YES.
Well said, Derek.
Concise and understandable to the layman.
Fair enough Derek, BUT, a cooler CO2 molecule will not emit a photon at the same wavelength as the photon it has absorbed from a warmer CO2 molecule; this, as I understand it, was what Nasif was referring to earlier in his post on ‘microstates’. If the photons emitted from the cooler CO2 molecules are not at an absorbing wavelength they will not be absorbed by lower warmer CO2 molecules. However the point of luke’s backradiation is that it warms the ground which will absorb a range of wavelengths: or will it?
Sorry Cohers but what you’ve written doesn’t make sense. A ‘warm’ CO2 molecule may emit an IR photon if it has enough excess energy and it’s net energy will decrease by exactly that amount. A ‘cooler’ CO2 molecule may absorb said photon and will then increase it’s energy by exactly the same amount. The ‘cooler’ CO2 can then re-emit an IR photon at exactly the same wavelength as the original photon emitted by the ‘warm’ CO2 molecule and so forth back and forth, back and forth ad infinitum. This is basic quantum mechanics.
Co2 molecules disperse the extra energy gained from absorbing IR into bond an rotational oscillations of discrete frequencies. The only difference between a ‘warm’ CO2 molecule and a ‘cold’ one is the extra kinetic energy that the former has.
WRT Luke’s point on backradiation, any molecule that has emitted a specific wavelength of photon can always reabsorb at the same wavelength. Therefore, any IR that reaches the ground and encounters the same compounds will definitely be reabsorbed and subsequently re-emitted.
As CO2 is dispersed throughout the atmospheric column, I would suspect that much of the IR directed downwards would be reabsorbed before it reaches the ground. I’ve read somewhere that the excited state remains metastable on average longer then the probability of a collision with a neighboring air particle and will tend to lose it’s energy kinetically rather than radiatively. This would lead to a very slight warming of the surrounding atmosphere.
So what is sceptic interpretation of the net radiometer –
http://en.wikipedia.org/wiki/Net_radiometer – two pyranometers measuring SW downwards and SW reflected upwards and two pyrgeometers measuring LW upwards and LW downwards.
A typical diurnal measurement could be in Figure 2 here http://scienceofdoom.com/2010/07/31/the-amazing-case-of-back-radiation-part-three/ 14 August 2000 in what looks to be a cotton crop.
Why do the energy balance measurements make sense? Sceptics pls help !
“The ‘cooler’ CO2 can then re-emit an IR photon at exactly the same wavelength as the original photon emitted by the ‘warm’ CO2 molecule and so forth back and forth, back and forth ad infinitum. This is basic quantum mechanics. ”
No, that is basic BS!
Forget any thermodynamic laws for the moment, a molecule may absorb an incoming photon if it’s cooler but it will not emit one unless an external energy source warms it enough to emit.
“back and forth ad infinitum.” my God! you just invented the ‘Perpetum Mobile’.
I’m sorry Jonathan but I think that you have misunderstood. Once the ‘cooler’ CO2 molecule absorbs an IR photon it is no longer ‘cool’. I just kept referring to it as that for labeling purposes. And it’s not just basic quantum mechanics, the concept of emission and absorption spectra is basic high school physics and chemistry.
The problem with the whole ‘warm body’ / ‘cold body’ thing is that posters have been treating gaseous layers as if they were homogeneous i.e. that all molecules in that layer were in the same energetic state. They are not, treating a layer of gas as a body is just averaging. Individual molecules within each layer may be warm or not so warm, hence my original submission stands uncorrected.
By not following it up with a counter argument doesn’t mean I concede, I just cannot be bothered.
But you are right in one thing, “basic high school physics”,
wish some would remember it though!
All,
I am new here, but in regards to ‘backradiation’, and can a cooler body heat a warmer one, there is a very good explanation and discusiion at Dr. Roy Spencer’s website:
http://www.drroyspencer.com/2010/07/yes-virginia-cooler-objects-can-make-warmer-objects-even-warmer-still/
It discusses how a body being heated externally to a given state CAN become warmer with a second (and unheated body) placed next to it. The second body does warm from the first heated body, and radiates some of its energy back to the heated body, resulting in a warmer state than would be WITHOUT the second body.
Note that the ‘net energy flow’ is still from hotter to colder, so there is no violation of the 2nd law of therodynamics.
It could be interpreted that the second body is acting like ‘insulation’, slowing down the loss of heat from the first body (which because the first body is BEING HEATED by an external source, it does become warmer than without the second body).
The CO2 (or water vapor or any other ‘greenhouse’ gas) in the atmosphere is acting like the ‘second body’ in Dr. Spencer’s example, in that it does absorb and re-radiate some of its energy back to earth, resulting in a warmer surface than would be if the CO2 (or water vapor for that matter, or other ‘greenhouse gases’) weren’t there.
My response to Martin’s recent post
http://jennifermarohasy.com/blog/2011/02/more-on-the-stefan-boltzmann-equation/?cp=2#comment-472133
Martin’s ‘response’ is essentially a snow-job. I’ll comment on five elements therefrom. (Some elements are in the form of quotes, and others are not.)
•”Nasif Nahle has responded quite incisively to Field’s comment by explaining how the distribution of energy levels constrain the system to transfer photons only from the hotter object to the colder one.”
Codswallop! Imagine a physical set-up involving two CO2 gas samples, each of which is enclosed in a glass container. The two glass containers are near each other, but are not in direct physical contact. Container W is a few degrees warmer than Container C, but both containers are within the normal temperate terrestrial range. It is NOT true that ALL of the CO2 molecules in Container W are in IDENTICAL excited states. It is possible for an excited CO2 molecule from Container C to emit an IR photon that’s absorbed by a CO2 molecule in Container W, thereby contributing to a miniscule and extremely short-term warming of that container.
I’d like to quote from Stephen Toulmin’s book, The Philosophy of Science:
“There is, so to speak, a division of labour in
physics, between laws themselves and statements about the
ways in which, and the circumstances in which laws are to be
applied.”
The 2nd Law is essentially true on a long-term macroscopic level, but is not necessarily always true in the extremely short term, especially on a microscopic level. (However we’re not able to exploit the extremely short-term microscopic deviations from the 2nd Law as an energy source.) Which parts of the expressions “short-term” and “microscopic” are you failing to comprehend? And where did you get your PhuD: In a Crackerjack box?
•”For the record, the case I considered maintained both surfaces at a constant temperature regardless of the radiativie transfer involved.”
Who appointed you as the tin god of the back-radiation issue? Cohenite asked a good question, and I framed it as an experiment. Sorry to be the bearer of sad tidings, Your Lordship, but cohenite and I are each free to approach the central question of your article from whichever angles we jolly well please.
•I’m taking the high road, in contrast to Muckraker Larry. Therefore I’m correct.
•I can spout pious platitudes about the 2nd Law. Aren’t I wonderful!
The usefulness of the 2nd Law is not in dispute. However your non-mainstream Fundamentalist interpretation of the 2nd Law is fair game.
•Martin also included a tediously long quotation from a past publication of his, as filler.
Unfortunately that quotation has precious little to do with the question at hand.
Overall, Martin provided a bureaucratic, non-substantive response. That’s some some high road you’ve got there, Bubba! Yes, you’re a good little techie, a good little bureaucrat, and a good little player of political games. But are you competent as an an independent scientific thinker? Don’t make me laugh.
Martin, your article is a joke. I’ve got you by the proverbials, and in your heart of hearts, you know it.
From Nasif, “The radiant energy is emitted to all directions, but the hot system cannot simply absorb the originating photons from a colder system because the warmer system photons have an energy density microstate higher than the colder system and, according to the definitions above, the absorption of radiating energy is an irreversible process. The second law supports what I am saying:”
I’m sorry but this is talking about the energy density of a system and then implying that individual molecules within the system are bound to the average of the system and can’t act independently. This analysis is simply wrong as I’ve already shown.
Secondly, “the absorption of radiating energy is an irreversible process” please, think about that statement for just a microsecond!
Think about this realistically, if , as has been claimed, IR from a colder source can’t be absorbed by a warmer system, then where is it going to go? Are you people saying that it has to go all the way back down to the ground, simply bounce off and fly all the way out into space again? ‘Cause nobody wants it?
I think we all need to take a deep breath here and regroup.
Firstly, most of the heat in the atmosphere is close to the surface. Why is this? Because SWR makes it all the way to the ground and then gets re-emitted as LWR that is absorbed by gasses in the low atmosphere causing vibrational and rotational excitement which is then transferred kinetically via COLLISIONS to neighbouring air molecules. Most of this is done by water vapour which also absorbs in the IR and most of the other gas in the atmosphere (N2) doesn’t. This means that probably not much IR is being re-emitted up, only to be absorbed and re-emitted down again.
I have no doubt that Luke’s assertions about the flux of back radiation are correct, so this does indeed beg the question; where is it coming from?
For the backradiation to be coming from CO2 in the upper atmosphere at 5am implies that those squirraly little molecules are maintaining a metastable state for an increadably long time as apposed to microseconds in the literature(from memory).
Guys; back to school please!
http://www.school-for-champions.com/science/infrared.htm
And get off this quantum stuff, at least long enough to consider some spectroscopy
http://www.wag.caltech.edu/home/jang/genchem/infrared.htm
I’m sorry Gavin but once again going to your links was a complete waste of time and contributed nothing to the conversation. My advice? If you don’t understand the concepts discussed, do what I frequently do, either keep quiet or at best ask clarifying questions.
Cheers.
Momentarily bypassing gav’s as always sage advice; where I think the discussion is erring is by focusing on individual CO2 molecules; convection and radiative transfer of energy in the atmosphere is constrained by LTEs; parcels of air which are in energy terms defined by Zeroth’s law; effectively radiative transfer of energy in the atmosphere does not occur on an individual CO2 basis but is based on the transfer convectionally of discrete parcels of air which are internally thermodynamically homogeneous; these LTEs do not have radiative transfer of energy internally or with the external atmosphere until they reach the characteristic emission layer[CEL], typically about 6 kilometers above the ground; at that level isotropic emission may occur but not at an individual level but in terms of a large parcel of air which will have its radiative emissions defined by Wien’s Displacement Law. The emissions of a high LTE will be at a lower wavelength than lower air because it is cooler due to the expenditure of energy to reach the CEL; therefore those cooler wavelengths will not be absorbed by lower CO2 because they are at lower wavelengths.
Derek@&;20 – “For the backradiation to be coming from CO2 in the upper atmosphere at 5am implies that those squirraly little molecules are maintaining a metastable state for an increadably long time as apposed to microseconds in the literature(from memory).”
hmmmm – not sure – the surface is still emitting – check out Fig 2 here http://scienceofdoom.com/2010/07/31/the-amazing-case-of-back-radiation-part-three/ Upward and downward LW fluxes are continuous – with downward LW of course always slightly less …
Sorry to keep coming back to measurement – as I’d like those sceptical to explain what is observed here by the net radiometer in The Energy Balance Experiment EBEX-2000. Part III: Behaviour and quality of the radiation measurements, Kohsiek et al, Boundary Layer Meteorology (2007)
I’ll make one comment about the discussion on “radiation” etc – and that it’s essentially a discussion about physical things that we cannot see but infer indirectly from theoretical considerations. Even more pertinent is our inability to conduct experiments on things we cannot see. All the acrimony is over things that are effectively invisible and essentially intellectual constructs.
Luke’s conclusion is simply a non sequitur, that because Martin has shown that thermodynamically a cooler object cannot warm a hotter one, then, illogically, Martin and I reject the fact of measured down-welling IR during night time. And redirecting the argument from the macroscopic to the microscopic is a variation of the straw-man debating ploy as well as venturing into the invisible domain where skills in rhetoric trump empiricism.
The intuitively illogical assertion that a cooler body might warm a hotter one is based on the behavior of unseen photons and imaginative constructs and is a direct result of the belief that the measured down welling night-time IR is solely from radiating gases in the atmosphere. If it were accepted that this down welling IR was actually from another operating physical process in the atmosphere, then there would be no need for the intellectual gymnastics to show that it’s due to radiating gases.
If thermodynamically it is shown that this is impossible, then a scientist would start wondering what else could be producing the measured down welling IR. The non scientific would, instead, invent ad hoc variations to the existing scientific assumptions.
Arguing in the microscopic realm is much like the devout arguing about the authority of the divine, both being derived from authority than empirically determined observations.
It’s basically a case of mechanics ignorant of electricity trying to understand the workings of a Prius automobile.
Here most of your are waffling about unobservable phenomena associated with the idea of radiation – CAGW is most definitely a phenomenon of the macroscopic.
Well Louis old trout – here’s some difficulty for your bold assertion …. (and for a bloke such as your good self who messes around with a fair share of geologist devices I’m shocked that you’re not full bottle on this)
http://www.patarnott.com/atms749/pdf/LongWaveIrradianceMeas.pdf
“Results of nighttime and daytime pyrgeometer precision and absolute uncertainty
are presented for eight consecutive days of measurements, during which period downward
longwave irradiance varied between 260 and 420 W m. Comparisons between .
pyrgeometers and the absolute ASR, the atmospheric emitted radiance interferometer,
and radiative transfer models LBLRTM and MODTRAN show a surprisingly good
agreement of 2 W m for nighttime atmospheric longwave irradiance measurements
and calculations.” ….
See Figure 3 !!
So it’s pretty awkward isn’t it – downward longwave agreeing with radiative transfer models.
So one makes the hypothesis – develops the model – goes into the field and remarkable correlation with measurement. Oh dear. Stick that up your micro-state ! And they didn’t have any plasma electric uni-bloody-verse do-hickies in that code.
Luke,
I have read your citation and they start with an assumption:
“Atmospheric longwave downward radiation is directly related
to the greenhouse effect. This dependence and its small
year to year variation makes longwave downward radiation at
the Earth’s surface a very promising element for monitoring
climate change with respect to global warming.”
Not awkward at all, and like the IPCC, assumes the conclusion it’s asked to confirm.
Stupid is as stupid does.
luke, it seems to me that Philipona can offer a clear disproof, or otherwise of Miskolczi. Since Philopona has been measuringd DLR since Adam was a boy he must be in a position to state whether DLR has INCREASED over the period he has been measuring; if it has then that would counter Miskolczi’s observations of a constant Tau, the optical depth, and that the greenhouse effect has not changed in 61 years of NASA observations. For the greenhouse effect to be causing the current warming DLR must be increasing; has it?
Louis
Being able to usefully conceptualize the invisible has been integral to the progress of science.
And I’m very visual, so I much prefer a graph, for example, to an explanation.
And I have found the commentary provided by Nasif and Derek very useful in terms of helping me visually conceptualize some of the issues.
Derek
I have sent you an email suggesting you develop something for a new blog post to continue/progress this discussion.
Oh for heavens sake Cohers – what utter diversions to this debate
But sigh …. yes – http://www.agu.org/pubs/crossref/2009/2009JD011800.shtml and http://ams.confex.com/ams/Annual2006/techprogram/paper_100737.htm
Louis – that is so utterly weak …. you’ve just run away ya big chicken. Not even a hint of a thought. It’s all just too hard isn’t it Louis. You’ve been confronted with measurement and as usual all we get is lah lah lah – Al Gore, IPCC ,commies blah blah ….
Luke, a good point about the ground continuing to emit after dark and I also thought about horizontal emission from the twilight zone prolonging the effect. But I don’t know how high up IR manages to get before all of it is reabsorbed. I’m just guessing but I assume most of the activity would be in the lower atmosphere. I haven’t read your backradiation papers but could you tell me at what maximum altitude the instruments were placed?
BTW, what’s the upward daytime IR flux just above the ground and how does it compare to the downward flux at the same height?
Cheers.
Ah yes, the Evans paper; Evans needs to be looked at in respect of the K&T ‘definitive’ diagram of backradiation:
http://www.atmos.illinois.edu/colloquia/080430.htm
K&T show a huge amount of backradiation of 323W/m2; the bulk of this is in the 15um wavelength; is it from water or CO2? What does Evans say: Measurements of the Radiative Surface Forcing of Climate, W.J.F. Evans & E. Puckrin, American Meteorological Society, 18th Conference on Climate Variability and Change (2006). From Evans and Puckrin we see in tables 3a and 3b);
Winter
H20 94 to 125 W m-2
CO2 31 to 35 W m-2
Summer
H20 178 to 256 W m-2
CO2 10.5 W m-2
Not only did the relative CO2 contribution drop in Summer, but the back radiation value decreased from about 30 Winter to about 10 W/m2 Summer.
How do these Evans and Puckrin (2006) values compare with and confirm the energy estimates in K&T?
The back radiation shown in the K&T chart is 323 W/m2.
Data from Evans and Puckrin suggests that CO2 accounts for at most 10% of K&T, and in Summer, CO2 is only about 3% of the K&T back radiation.
To get close to the K&T back radiation values, there apparently needs to be a LOT of water in the atmosphere; CO2 would only be relevant if there were no water.
What have water vapor levels been doing? Soloman shows declines since 2000 at the crucial high altitudes, as does Randel. Pierce shows similar:
http://meteora.ucsd.edu/~pierce/papers/Pierce_et_al_AIRS_vs_models_2006GL027060.pdf
Paltridge shows a general decline since 1973 at high levels. SH has been rising at low altitudes during this period which would satisfactorily explain any temperature increase; but then so would the increased SW hitting the deck during this period as Pinker found. So luke there is no need to invoke DLR at all; SH and SW can explain all temperature movements since 1973.
Good comment on Lubos Motl’s blog
Gene
I just ran across a 1939 quote by Upton Sinclair:
“It is difficult to get a man to understand something when his salary depends upon his not understanding it.”
Typing error in my comment above -Gavin Schmidt is at RC (Real Climate) not CR.
Lumo’s post http://motls.blogspot.com/2011/02/in-denial-climate-on-couch.html shows some of the sheep on the believers side are concerned people are not listening to them. The video of the Czech singer is a divergence -you do not need to understand Polish or Czech in the original version. (The BBC program is also mentioned at WUWT and Bishop Hill)
Derek – the radiometers appear to be at a fairly standard 2 metres height for field meteorology. Radiation models have many layers through the atmosphere. Have a look at Figure 2 here – there’s about 50 w/m2 difference in LWu and LWd at night and about 150 in the middle of the day. “An” example from “a” site on “a” day. Of course the Air Force in developing radiation models developed much of the altitude aspects.
Cohers – you shocker – that’s hardly a numeric calculation is it? A little grab bag of factoids. Solomon indeed – stratosphere not troposphere and a small component. The changes in DLR is due to CO2, water and temperature…. and the flux from greenhouse gases are indeed real as Evans spectral analysis shows http://www.cccma.ec.gc.ca/papers/jli/pdf/puckrin2004.pdf – and indeed more than simulated – that should be the end of it.
Luke
Do you realise that there is more radiation going up from the pyrgeometers than is down-welling into it.
A subtraction is made to the flux removing the upward LW to try to work out the DLW .
This is why it makes no sense to talk of the atmosphere “heating” the warmer surface.
In thermodynamics the word HEAT has a meaning quite different to the vernacular meaning.
Get a physics book and look up the Carnot cycle and find out how heat is used in a thermodynamic sense.
Given particular high and low temperature surfaces heat is the free energy available to do WORK.
So to identify which direction heat flows it can do two obvious things.
1. Raise the temperature of the other surface
2. Do some work eg steam engine and deposit unused part of heat into cold surface.
Then ask yourself if the colder atmosphere heats the warmer earth surface.
Ah luke, you get very cocky when you think you are a winner; you have been flogging backradiation and Philipona for ever; a couple of points; your figure 2 from SoD:
http://scienceofdoom.files.wordpress.com/2010/05/planck-283-263.png
Proves my point about Wien distribution; parcels or levels of air at different temperatures will emit radiation at a different frequency distribution which means Derek may or may not be right at a molecular level but at a macro level it is definately the case that the emissions from a colder air body will have a different spectrum than a warmer one which will affect the capacity of other gases to absorb those emissions.
You say: “there’s about 50 w/m2 difference in LWu and LWd at night and about 150 in the middle of the day.” And indeed there is great variation at any one time between Ed, that radiation leaving the atmosphere and going back to the surface and Aa, that radiation going from the ground and being absorbed by the atmosphere [as expressed in Miskolczi terms]; but over any reasonable time, such as a day, both Ed and Aa, or LWd and LWu even out; see Figure 11.1 from:
http://books.google.com.au/books?id=KaJHBv9FbYIC&printsec=frontcover&dq=Geiger%E2%80%99s+%E2%80%9CThe+Climate+Near+The+Ground%E2%80%9D&source=bl&ots=2vWksoLUjX&sig=uzVQx1QlpuuIgcLfqjFI7x7-Eas&hl=en&ei=t_1oTJy5B5DCcYLg3awP&sa=X&oi=book_result&ct=result&resnum=1&ved=0CBQQ6AEwAA#v=onepage&q=Geiger%E2%80%99s%20%E2%80%9CThe%20Climate%20Near%20The%20Ground%E2%80%9D&f=false
Geiger also is helpful in calculating the level from which the bulk of the LWd or Ed comes from and that is discussed here:
http://scienceofdoom.com/2010/08/15/height-of-emission-of-olr-and-dlr/
That is 90% of LWd/Ed comes from about 500 metres. Now it is true that SH has been increasing but only at lower levels; the Soloman and many other papers show high water is declining; what this means is that the LWd/Ed increasing effect produced by lower water is negated by the decline in higher water; high water is very effective in blocking OLR; as Lindzen and Choi and Knox and Douglass show OLR has been increasing.
Put in a nutshell, your Evans and Philipona links are wrong. AGW is still searching for one real confirmation; Miskolczi has several.
But keep spluttering luke, sometimes you even make me pause and think: well maybe there is a point there; one day you’ll be right but not today.
Firstly; Luke, there wasn’t a link where you said ‘here’ but I did read the whole CCCMA paper. Thanks for that , it was VERY informative, there was so much in it that I’m saving it for more detailed perusal. Totally unrelated but if you look at fig 1 and fig 2 there is both a definite relationship between temp, altitude and gas concentrations as well as an inverse relationship between fig 1 and fig 2., you could actually draw a line through successive graphs in each fig. Now that’s what I call correlation. Unfortunately I have neither the time or capacity to investigate this further.
You may have scored an own goal however as the paper clearly shows that water totally dominates the downward IR flux, particularly in the tropics, and also demonstrates significant inaccuracies in the climate models analyzed.
Nevertheless, the information on actual experiments was most informative and has provided both quantitative and qualitative clarification of the issue.
Cohers, I’m not normally at odds with you (maybe I should check my meds), but I can’t see what you see in fig 2 fro SOD. If I read the graph correctly, the only change is in the amplitude of the signal with no shift in wavelength. I have seen other graphs before that show concentration or temp and from memory the same happens, amplitude change. Unfortunately, a bad habit of mine is to look at something and move on so I can’t reproduce said graphs.
Do you have anything else that demonstrates your point?
Cheers.
Cohers, the idea that 90% of LWd comes from below 500m makes intuitive sense and suggests a correlation with humidity levels as shown in fig 1 in Luke’s paper. One thing I have difficulty with is rationalizing the volume of backradiation from all sources with the initial total solar irradiance watts per square meter, the former just seems too large for me.
Hi Derek: “One thing I have difficulty with is rationalizing the volume of backradiation from all sources with the initial total solar irradiance watts per square meter, the former just seems too large for me.”
I think that is the problem for a lot of people. In regard to Wien, I use this calculator:
http://hyperphysics.phy-astr.gsu.edu/Hbase/wien.html#c3
The peak shift is slight but the total energy is not between the temperatures on SoD’s graph; I take your point about amplitude but are the differences in peak and energy a product of the gas components being different or similar ratio of gases with different heats and therefore emissions?
Martin had problems posting the following:
“Fields is a hopeless case. What should be a rational discussion about the facts or the science inevitably degenerates into an insulting and vicious harangue.
The example I gave of the line reversal method for measuring temperatures clearly illustrates a “tipping point” (AGW terminology!) that occurs when the two temperatures are equal and the flow of radiation reverses depending on whether the flame has the higher temperature or the blackbody has the higher temperature. It is clear experimental proof that the 2nd Law applies to radiation.
That Field’s only response is to heap further insults means that he either doesn’t understand the point that was made or that he prefers diatribes to scientific discussion.
Responses to him seem only invite further insults, so good bye and good luck Mr. Fields.
Dr. Martin Hertzberg”
******
Larry, perhaps the spam filter is on your side? 😉
Whether DLR is having a net warming effect or not is hard to asses but here’s something that is very easy to asses:
Yesterday I left my home in the bush with the car thermometer reading 25 c. Twenty minutes later I’m on the freeway with the thermometer reading 32 c.
Now that’s AGW.
But not ACO2eGW.
Luke writes:
“Louis – that is so utterly weak …. you’ve just run away ya big chicken. Not even a hint of a thought. It’s all just too hard isn’t it Louis. You’ve been confronted with measurement and as usual all we get is lah lah lah – Al Gore, IPCC ,commies blah blah ….”
I quite accept the existence of the down welling IR – except that it’s likely not to be coming from CO2 but some other source since Martin Hertzberg has shown that it can’t be coming from a cooler gas.
But somehow you have concluded that if we assert that thermodynamically a cooler body can’t warm a hotter one, then that also means that we deny the existence of the measured down welling IR, then you have it totally wrong.
I can’t speak for Martin but I’ll repeat it for my position in this argument – there is indeed DOWN WELLING IR, it’s just that it can’t be coming from a cooler gas for basic thermodynamic reasons.
Jen,
The point I made was debating over things we “think” are occurring at the microscopic level, and indeed using visual aids to high light such ideas is useful, providing those ideas are sensible.
Hi Cohers, Wien’s radiation curves graph shows both an increase in magnitude and a shift in wavelength as a blackbody is heated. In simple terms it’s what happens when you heat a piece of metal and it goes from red to blue to white hot. Wien’s graph and the SOD fig 2 graph are not related and I don’t think one can use the physics of black bodies for molecules as it doesn’t take into account molecular bonds.
As far as SOD fig 2 is concerned, energy is energy and it doesn’t matter where it came from, it can be converted into another form. Therefore, as long as the total energy of a molecule is greater than that of an IR photon, it can emit said photon. This means that a CO2 molecule doesn’t have to have absorbed a photon before it can emit one. Thus, the higher the average temperature of the system, the greater the number of molecules within that system are able to emit IR photons. Hence, SOD fig merely shows that at a higher temp., more CO2 molecules are emitting IR but the wavelength range remains the same.
I might remind the listeners that the blackbody radiation idea is based on a fictional body the is able to emit photons in a continuous spectrum. In reality there may be some heterogeneous substances (think basalt) that could approximate the spectrum of a blackbody but not, I would contend atmospheric gasses.
Cheers.
Cohers, I just had another look at SOD fig 2 and maybe the 2 graphs are related but there is not enough info with the SOD graph and it’s not related to IR specifically nor does the link mention any specific gasses.
Derek – “here” was http://scienceofdoom.com/2010/07/31/the-amazing-case-of-back-radiation-part-three/
Cohers – Of course we could get into Harries but not Mk I http://ams.allenpress.com/archive/1520-0442/20/15/pdf/i1520-0442-20-15-3982.pdf
hmmmm water vapour feedback http://www.ingentaconnect.com/content/tandf/tres/2008/00000029/F0020017/art00023
And Cohers – thought you’d like Rolf’s radiometer kit http://www.dwd.de/bvbw/generator/DWDWWW/Content/Projekte/Gruan/Downloads/ICM-1__2009/pres__046__Philipona,templateId=raw,property=publicationFile.pdf/pres_046_Philipona.pdf you should correspond with him !
Nice lawn eh? Wattsy would get off on that.
So Louis – don’t you find it troublesome that complex radiation models reproduce the DLR observations. As an empirical guy you’d have to be worried or doing http://www.ostrichheadinsand.com/images/ostrich_head_in_sand.jpg
Luke, thanks for that, I’ve bookmarked the site as I just read parts 1,2 &3 and found then quite informative.
Cheers.
Luke,
I don’t find it troublesome at all – especially when you discover that they limit their reproduction to data collected on a cold winter day, and also admit that the modelling has problems with water vapour and nitrous oxide etc. It would be interesting to see the reproduction repeated on a warm summer day, or as we do in my area of scientific expertise, collect “representatative samples”.
In any case the GCM’s all start with the assumption of climate sensitivity – it’s inbuilt into the model so it’s not surprising they reproduce the measured results. They assume that the DLR is coming from greenhouse gases but as Martin pointed out, that is not thermodynamically possible, so the DLR has to be coming from another source, which is my point.
luke, I know inconsistency doesn’t botheryou but you have linked to the Prata paper which says this:
“It is suggested that increases in precipitable water represent a positive feedback on F↓.”
” F↓” is LWd. Now compare that with the Lacis paper [ http://www.sciencemag.org/content/330/6002/356.abstract ] on the primacy of CO2, compared with H2O, which says that CO2 is the dominant greenhouse gas because it does not precipitate.
Derek; I think this needs further elaboration:
“Therefore, as long as the total energy of a molecule is greater than that of an IR photon, it can emit said photon. This means that a CO2 molecule doesn’t have to have absorbed a photon before it can emit one.”
As you know the rate at which CO2 molecules are thermally excited [due to absorption of a photon] is much slower than the rate of collisional deexcitation; collision is in fact the by far dominant method by which energised or excited CO2 molecules divest energy and return to a stable state. This process of collisions is what forms LTEs, which I’m sure you also know about; Zeroth’s Law prevails in an LTE and no emissions occur. The LTE is the main way in which energy is carried in the atmosphere; they move upwards by convection at a rate determined by the lapse rate. I’m not sure how an unexcited CO2 molecule or a CO2 molecule in an LTE can emit.
We have seen how the bulk of LWd is from a very low height, and that low level water vapor concentration has increased; given this and the LTE formation I can only conclude that any increase in LWd has been due to water vapor levels which is matched by a decline in high water vapor levels such that an increase in OLR matches any increase in LWd.
No Louis – lots of data at multiple sites. You’re simply hand waving and obfuscating.
Just somehow they’ve “fluked” a modelling process with hundreds of lines of code that reproduces the observations using a process that you say doesn’t exist. Uh huh !
And your comment about climate sensitivity in this context is utterly STUPID and irrelevant. We’re talking about radiation transfer codes – not GCMs. We’re not talking about “tuned” results. . You don’t even know what you’re on about. Which just goes to show your AGW objections are completely political and non-scientific.
Cohers, ya got me, I have no freakin’ idea what an LTE is. I even looked it up on google and couldn’t find anything.
An unexcited molecule or atom can’t emit a photon and even excited, or more precisely energetic molecules can only emit if their net energy is equal to or greater that the photon to be emitted.
Most of what I’ve talked about is WRT what CAN happen and is not necessarily an indication of what does happen.
“As you know the rate at which CO2 molecules are thermally excited [due to absorption of a photon] is much slower than the rate of collisional deexcitation; collision is in fact the by far dominant method by which energised or excited CO2 molecules divest energy and return to a stable state.”
This is exactly the point that prevents me from easily accepting the magnitude of LWd because the vast bulk of absorbed energy would seemingly be transferred to non IR radiative gasses that make up 99% of the atmosphere.
I must point out here that WRT radiative absorption/emission, it’s like a light switch, it’s either on or off. Kinetic energy transfer is however, not the same and you tend to get something of a bell curve of energy distribution whose peak moves with the increase or decrease in average heat of the system. Molecules can therefore engage in multiple collisions yet still retain enough energy for enough time for a radiative de-excitation. (Once again this is a ‘can happen” scenario)
Here’s a little thought experiment that just came to mind; suppose you had a beaker of water at 10 degrees and placed an electric radiator source just above it kept at a constant 30 degrees. As the water is warming, some of the molecules will have a very high energy and will escape by evaporation, leaving the beaker and colliding with the heat source. Would those high energy water molecules increase the energy of the heat source via collisions even just for a microsecond?
Derek, I did refer to a local thermodynamic equilibrium earlier but no doubt luke’s triumphalism has distracted us all; a couple of sources for LTE:
http://rabett.blogspot.com/2007/03/what-is-local-thermodynamic-equilibrium.html
http://geosci.uchicago.edu/~rtp1/papers/PhysTodayRT2011.pdf
In terms of our discussion about collisional deexcitation this discussion is helpful; see De Witt’s comments page 3, comment 252277:
http://ukweatherworld.co.uk/forum/forums/thread-view.asp?tid=16928&start=41
Jennifer wrote:
Larry, perhaps the spam filter is on your side? 😉
Sorry, my computer skills are not what they should be. After opening the email, I did the same for the spam folder, and only found the usual suspects. One of them is an acquaintance who spammed me about his brother-in-law’s auto repair business. Every few months, he breaks free from the virtual Siberian gulag, and I need to send him back.
I’m not sure why your message is not getting through, and his sometimes sometimes are. You may want to double-check the spelling. Did you substitute a “y” for an “e”?
Luke,
The paper you refer to states that they simulated 40 levels from surface to 100km, which suggests levels every 2.5 km (100/40), which is neither here nor there at first sight.
However according to Willis Eschenbach linked by Cohenite to a scienceof doom posted earlier,
“Mmmm … well, my copy of Geiger’s “The Climate Near The Ground” begs to disagree. It says that 72% of the DLR at the surface comes from the lowest 87 metres of atmosphere. Another 6.4% comes from the next 89 metres, 4% from the 93 metres above that, 3.7% from the next 99 metres, 2.3% from the next 102 metres, and 1.2% from the next 105 metres.
This means that some 90% of the DLR is coming from the first (lowest) 578 metres of atmosphere …”
which is a problem for you. (The data in Geiger are measurements, by the way).
Problem?If 90% of the measured DLR is within the first ~600 meters of atmosphere, then the simulation levels are missing most of the data, iff I have interpreted their statement of 40 levels over 100km correctly – that they are equally spaced levels 2.5km apart.
So what are they really simulating? They are assuming a constant gas concetration for the whole 100km, as they state, but while the chemical composition of the atmosphere is maintained as a constant, its absolute volume decreases upwards and thus must affect downwelling radiation since absolute levels of radiation depend on the physical amount of radiating gases. No mention of this is made in the paper. I note that their plots only show to 50 km as well.
And I note that they did not include the radiative effects of clouds or aerosols.
Quite amazing how much support Martin Hertzberg has.
In his work cited on Climate Etc he demonstrated that he had no understanding of Kirchhoff’s law. The stuff you find in the chapter on Radiation in an undergraduate textbook.
For example, in “Fundamentals of Heat and Mass Transfer” by Incropera & DeWitt (2007) it is on p30 of the chapter on Radiation.
In “Heat Transfer Textbook” by Lienhard & Lienhard (2008) it is on p8 of the chapter on Radiation.
If he believed that the standard theory was wrong, why not point that out? Citing a theory and then getting it wrong means that you probably didn’t even understand it.
Normally, that would be embarrassing.
However, Hertzberg believes that climate science is wrong, so getting basic theory wrong is.. not important.
In this article he is quoted as saying:
“Thus, the simple use of the Stefan-Boltzmann equation to characterize the emission from a source of radiation as though it depends only on the temperature of the source without considering the temperature of the surroundings that are receiving the radiation, is a misuse of the equation, and the notion that a colder source can transfer radiant energy to a warmer object involves not only a misuse of the Stefan-Boltzmann equation but also a violation of the 2nd Law.”
For people new to this subject, Hertzberg appears to claim that climate science “misuses” this standard equation.
So do all the heat transfer textbooks.
And all the courses on thermodynamics at universities.
In fact, Hertzberg, along with his co-writer, is claiming that 20th century radiative physics is WRONG.
His co-author, Claes Johnson, writes that Max Planck – Nobel prize winner in 1918 – was wrong.
Of course, that is possible.
However, it seems odd that so many people have embraced their claims. The last century of physics and heat transfer is wrong? The new faithful had been puzzling over Planck’s derivation for some time?
Intellectual prop, anyone?
And for his claim on the second law, see Amazing Things we Find in Textbooks – The Real Second Law of Thermodynamics.
So just imagine this Louis – a bunch of monkeys typing random code get a great match against obs. A million to one shot. Pffft !
El Gordo – here’s the full paper
http://www.kysq.org/docs/940.pdf
Many AGW believers who may know a little science appear to go on ego trips trying to empress followers by their knowledge when in fact they do not understand the complexity of engineering technology. SoD go and look in Perry’s Chemical Engineering Handbook which will be in the libraries of most of the better standard Universities (such as MIT and mabe even GIT). Particularly have a look at the section on the emissivity of combustion products (mixtures of H2O and CO2) and equation 5-145 if it is not beyond you. While you at at it try and discover something about convective heat transfer, evaporation, thermodynamics and fluid dynamics.
The concept of packets of energy being sent out from a surface to CO2 does not make sense and is not in accordence with the CO2 absorption spectrum.
I was trying to think of another analogy for the limited radiant heat absoption by CO2. I thought about a radio receiver picking up selected radio waves from a particular radio transmitter. Radio waves are part of the Planck black body energy flux spectrum which covers x-rays, ultraviolet, visible light, infrared, microwaves and radio waves. The power of the transmitter is not increased by another transmitter within receiving distance. In fact a second transmitter can cause interference. I am not an expert on this but the following makes an interesting assessment that the concept of photons is wrong http://www.worldsci.org/pdf/abstracts/abstracts_5711.pdf. As I have previously said for an engineer there is no need to agonise about the fine details of the theory as long as the results work. I repeat again that, from engineering calculations, the absorption by CO2 of radiant energy in the atmosphere is insignificant. To the best of my knowledge no one has shown in any way that CO2 has a significant influence in the lower atmosphere but there is evidence that CO2 has an insignificant role such as from icecores showing temperature leading CO2.
” I am not an expert on this”, ” for an engineer “, “I repeat again “, “To the best of my knowledge”, ” icecores showing temperature leading CO2″
cementafriend February 13th, 2011 at 10:40 pm:
Q1. Am I wrong that heat transfer textbooks state that emissivity = absorptivity for a given wavelength?
Q2. Does Hertzberg claim that absorptivity at solar wavelengths (centered on 0.5um) = emissivity at terrestrial wavelengths (centered on 10um) because of Kirchhoff’s law?
I look forward to your clear and unambiguous response to these 2 simple questions.
Perhaps I need a follow up to Amazing Things we Find in Textbooks – The Real Second Law of Thermodynamics.
SOD,
Could you explain again what is wrong with Poynting’s theorem please?
http://en.wikipedia.org/wiki/Poynting%27s_theorem
IR IS electromagnetic radiation isn’t it? The correct way to compute energy transfer between two bodies HAS TO take into account the energy from both bodies and the vectors involved doesn’t it??
Why don’t y’all believe in real physics?? It is the expression of Statistical Quantum theory!!
SOD,
please show us the math where the functions of the molecular bond simulate the functions of a black body. I mean there are so few bands in the molecular bond. There are also so few bands in the radiation of gas at whatever temperature. Slavishly applying theorems to situations that are not really applicable shows a poor attitude.
Maybe you should show the math that supports your contentions so real Scientists can decipher it? (not me obviously)
While I am complaining, please explain to us who read your Greenhouse Moon post exactly what you mean when you said that we could see the Greenhouse effect between the 390w/m2 alledgedly measure from the surface compared to the 240w/m2 measured at TOA??
First, these are based on two different areas. The surface area at TOA is larger. Second, if you computed that 390w/m2 based on emission to a vacuum then we are back to my question in the previous comment.
You and Steven have similar problems with your basic physics don’t you. Selective memory maybe?
SoD
Q1 I will quote Perry CEH P5-25
“According to Kirchhoff’s law, the emissivity and absorptivity of a surface in surroundings at its own temperature are the same for both monochromatic and total radiation.”
However, it is not that simple. I suggest that you look at Perry CEH equation 5-116.
The absorptivity of the receiver is the integral of the Planck function over all wavelengths at the temperature of the source. If the sun was a black body (which it is not), at a temperature of 5900+-200K, there would still be some radiation in the wavelengths (mainly around 15micron) where CO2 absorbs but the amount of energy absorbed relative to the total incoming radiation from the sun is practically zero. However, clouds and oxygen/ozone do absorb considerable amount of the radiant energy from the sun so amount arriving at the earth’s surface is substantially and variably reduced.
Q2 I can not find in Dr Martin Hertzberg’s statement anything like your interpretation. I can not imagine what is in your mind.
Did you read my link? There are many peer reviewed articles which doubt the existance of photons which have a specific quanta of energy. CO2 can only absorb and emit WAVES of electomagnetic energy in a very small wavelength range. Then there is only a trace amount present in the atmosphere. H2O in the form as vapour in the lower atmosphere and liquid/solid in clouds has a much greater absorptivity/emissivity and there is more present.
New at WUWT http://wattsupwiththat.com/2011/02/13/a-conversation-with-an-infrared-radiation-expert/#more-33954
and following comment is more or less in accordence with my estimation
Domenic says:
February 13, 2011 at 1:30 pm
I am an IR expert, 20+ years in the field.
CO2 is an IR absorber of only narrow wavelength bands of IR.
Water vapor is a much more stronger IR absorber because it absorbs very large wavelength bands of IR.
In addition, water vapor is approx 3.5% of the atmosphere or 35000 ppm. (That’s a global average. At the poles the air is drier. In the tropics, the air is much wetter.)
CO2 is only about 390 ppm.
So, water vapor from a ppm point of view is probably 100X greater in effect as a greenhouse gas from an atmospheric percentage only compared to CO2. (I rounded up slightly because the tropics have more effect than the polar regions, having more water vapor to absorb and store solar energy.)
In addition, a molecule of H2O is also quite a few multiples greater in absorption of IR compared to a molecule of CO2.
Take a look at absorption spectra for H2O: http://webbook.nist.gov/cgi/cbook.cgi?ID=C7732185&Units=SI&Type=IR-SPEC&Index=1#IR-SPEC
For CO2: http://webbook.nist.gov/cgi/cbook.cgi?ID=C124389&Units=SI&Type=IR-SPEC&Index=1#IR-SPEC
Just eyeballing these two NIST absorption spectra curves for H2O and CO2, it appears H2O may be at least 10X greater at absorption per molecule than CO2 is.
Thus, the comparative effects on ‘global’ warming, changes in H2O composition in the atmostphere are probably 1000X greater than CO2 changes in terms of contribution to ‘greenhouse effect’.
give or take a bit for some error =>>>>> approximately 1000 TIMES!!!!
CO2 is a non-issue compared to water in the atmosphere.
I have made comments elsewhere (eg http://tallbloke.wordpress.com/2011/02/12/sunspot-asymmetry-barycentre-to-solar-centre-link/) about the accuracy of measurement. I certainly agree with Mikael C in the WUWT article. Scientists just do not understand errors which are cumulative.
cementafriend from February 14th, 2011 at 10:35 am:
1. In answer to my question you cite another textbook that agrees with my point but claim “it’s not that simple”.
My question was, “Am I wrong that heat transfer textbooks state that emissivity = absorptivity for a given wavelength”?
I think your answer is “You are not wrong, you are correct”
2. This is the Hertzberg paper discussed on Climate Etc.
From p7 of his paper:
“As can be seen from the graph, for an average albedo of 0.367 (which equates with an absorptivity of 0.633) the only way one can obtain sub-zero temperatures as low as -20 to -25oC, is to have an almost perfectly emissive Earth (emissivity near unity). Such a unit emissivity assumption, however, directly contradicts the use of an albedo of 0.367. Since most of the albedo is caused by cloud cover, it is impossible for Earth to radiate out into Space with unit emissivity if 37% of that radiation is reflected back to Earth, or absorbed by the bottom of those same clouds. Even for those portions of Earth that are not covered with clouds, the assumption that the ocean surface, land surfaces, or ice and snow cover would all have blackbody emissivities of unity, is unreasonable. ”
Pretty simple that Hertzberg doesn’t understand Kirchhoff’s law. (Neither do the editors of E&E who published the paper).
This is why I should be surprised at his new following.
In fact, on Climate Etc, many people tried to claim that actually I didn’t understand Kirchhoff’s law. I cited from textbooks, offered to post up scans of other textbooks. All in vain.
Obviously if you write something which concludes “..and more CO2 therefore has no effect on the climate“, then everything that comes before is pretty much guaranteed correct.
It’s a novel approach to science.
Hi cementafriend; I appreciate your comments; I am having trouble seeing the much larger H2O absorption capacity from the 2 links in your reference to Domenic; some guidance would be appreciated. In fairness to SoD, ‘he’ has recognised the greater greenhouse capacity of H2O compared with CO2 and has posted this table from Ramanathan:
http://scienceofdoom.files.wordpress.com/2010/02/ramanathan-coakley-1978-role-of-co2.png
SoD comments in respect of Table 6: “What it says to me is that overlap must be significant because if we take out water vapor it is only a 25% effect. And if we take out CO2 it is a 9% effect. (I have emailed the great V. Ramanathan to ask this question, but have not had a response so far.)
Therefore, guessing at the overlap effect, or more accurately, assigning the overlap equally between the two, water vapor has about 2.5 times the effect of CO2.”
Still 2.5 times is a lot less than 10X or 1000X!
SoD also posts this graph depicting the backradiation from CO2 and H2O at the 15 mu wavelength:
http://scienceofdoom.files.wordpress.com/2010/07/spectra-h2o-co2-15um.png
CO2’s peak wavelength is around 15 mu so that is not surprising and this graph of course does not take into account water as cloud.
cohenite on February 14th, 2011 at 1:16 pm :
The most important aspect is not the surface (downward flux), it is the TOA flux.
I wrote the 3 articles about back radiation – radiation from the atmosphere – because so many people believed it didn’t exist, didn’t result from “greenhouse” gases, and/or couldn’t be absorbed by the surface.
Take a look at the simple models starting in Understanding Atmospheric Radiation and the “Greenhouse” Effect – Part Two and especially Part Four.
These help illustrate that the TOA flux is not a “mirror image” of the surface flux.
And once these points are understood you realize that you want to know the impact on TOA flux as a result of the various radiatively-active gases.
By the way, yes, I know it’s a model. It’s a model to help illuminate the subject.
To actually produce the answer you have to either:
a) solve the radiative transfer equations and show your answer OR
b) demonstrate why these equations are incorrect (and what the real equations should be)
You can’t solve the radiative transfer equations analytically, and you need to include the absorption/emission values of all the radiatively-active gases at all wavelengths. There are 2.7M lines in the HITRANS database. Not all fall into the terrestrial wavelengths, but there’s still a lot. Making it a difficult problem.
Not a problem you can do in your head.
SoD, I don’t think anyone was saying the TOA flux is a “mirror image” of the surface flux. I presume you are alluding to the recent Knox and Douglass paper:
http://www.pas.rochester.edu/~douglass/papers/KD_InPress_final.pdf
Knox and Douglass state “As many authors have noted, knowing FOHC is important
because of its close relationship to FTOA”; FOHC is defined as the rate of change of OHC divided by Earth’s area and FTOA is the radiative balance at TOA. If FTOA > FOHC, “missing energy” is being produced if no sink other than the ocean can be identified. K&D conclude that that neitheris there another sink and energy is not being stored in the ocean so therefore FTOA is not in positive imbalance.
The point about K&D’s rather nifty method of calculating whether there is a TOA imbalance is that there are ways around your 2 choices of producing the ‘answer’. Of course Miskolczi has chosen the hard way of a) based on his own data; I guess that is why noone is still touching him!
cohenite on February 14th, 2011 at 4:45 pm
“I don’t think anyone was saying the TOA flux is a “mirror image” of the surface flux..”
I wasn’t alluding to that paper at all. (Having a quick scan through it doesn’t seem that relevant, but I will take a closer look).
It’s just that I’ve come across this misconception a lot. So I thought I would point it out – the surface spectral measurements are not a useful guide to the more important TOA spectral measurements.
God this is painful Cohers. Most of us only have Pentium III processors onboard. Obviously you have a multi-core Sandbridge.
So tell me – what is your interpretation of what our good friend Rolf is measuring with his pyrgeometers.
So he’s measuring downward longwave ?
or is the instrument wrong?
or if the measurement is right you’re saying it does nothing?
Honest questions.
Luke:
” So just imagine this Louis – a bunch of monkeys typing random code get a great match against obs. A million to one shot. Pffft !”
Thanks, you just scored another own goal.
Has it not occurred to you that if 90% of measured DLR between the surface and approximately 600 metres elevation, that CO2 can’t be producing it? (or for that matter any of the greenhouse gases since they are of necessity well mixed). If it is attributed to CO2, then that means the earth’s atmosphere is enriched in CO2 in the first 600 metres.
If air can be considered physically an isotropic phase, then its emissivity should gradually decrease upwards as a function of density ( or pressure) everything else being equal. That it doesn’t, since it abruptly diminished by up to 90% in the first 600 metres, supports my case that the measured DLR is coming from something else.
Or perhaps it has occurred to you, hence your responce with a another strawman argument.
Hilarious – do you think before you write Louis. So the radiation modellers have got the right answer (matching the obs) by a totally incorrect model formulation. LOL ! Keep going Sinkers.
Perhaps the DLR is coming from the Big Cookie monster in the sky.
Luke
You are confusing EM radiation with heat.
DLR is IR EM radiation
SoD also is very confused in that area.
IR radiation only becomes heat if and when it is absorbed by the colder surface.
The flow of heat is the difference in the two radiations between hot and cold surfaces.
It always flows from hotter to colder never the reverse.
Heat is the free energy available after the radiative interaction that is available to do work.
Work can be converted into other energy forms or simply used to raise the temperature of the colder surface.
I think people are confusing NET radiative transfer with the possibility of individual events occurring. Neither SoD nor Luke or myself are saying that more IR is directed down than went up in the first place.
I know I’m being anal but I take issue with statements like “It always flows from hotter to colder never the reverse” which in this context implies that there is somehow something unaccounted for by the theory and actual experimental evidence that magically prevents IR from radiating in the downwards direction if the overall body in question is even slightly cooler.(pause for breath)
Forget the high brow equations for a sec, does that SOUND even reasonable?
Yep NET is the issue.
Yes net; and isn’t that what the guy is saying?
I (net) = s (Th4 – Tc4 )
And Bryan has hit the nail on the head; the pyrgeometers whatchmacallits are obviously measuring a lot of LWd; that amount of LWd should be doing more than it is doing even if we assume the official temperature indices are real [big assumption]; about that amount and pyrgeometers one Morris Minor at SoD says this:
“The case for ‘back radiation’ is weak. Nothing here gives evidence that ‘back-radiation’ has been detected or measured. The papers quoted do not show measurement of back-radiation. Instead they measure upward radiation and subtract this value from a hypothetical value relative to abs. zero. The difference is the so-called back-radiation. Surely a value of 300W/m2 would seem implausible to most, it is comparable in magnitude to radiance from the sun!
Here is how it is explained by the makers of a typical Pyrgeometer..
“In order to calculate the incoming LW irradiance at the detector, the temperature of the pyrgeometer body must be known. … The downward longwave radiation is then calculated using the following formula :-
LW = Uemf/S + ( 5.67*10-8 * Tb4 )
where Uemf is the output voltage from the thermopile, S is the calibration constant of the instrument, and Tb is the pyrgeometer body temperature, measured by the thermistor, in degrees Kelvin. Note that for an upward facing pyrgeometer, the thermopile output voltage will in most instances be negative. This is because the upwelling irradiance from the pyrgeometer is likely to be greater then the incoming irradiance from the sky. “
I therefore challenge anyone on this site to show me direct evidence of back-radiation. Better, show me a method to power a 40W light globe using back-radiation. It should be easy as there is 300 W/m2 available. If back-radiation is able to raise the temperature of the Earths surface then it will be possible to harness this energy to produce a small electrical generator. The first person with a solution wins a multi-million dollar share of the IP rights.”
There you go luke; I challenged good old gavin to go out the back and warm his saucer of water or milk or bonnox; the challenge for you is to go out the back at night, stick a lightbulb in your gob and see if it lights up.
Perhaps we could solve with nano-antennae
luke, old sport, your backradiation thinngy is a bit of swiss cheese; following on from my earlier comment, some smart chap observed this about the Pyrgeometers and other LWd measurement devices:
“Positive voltage = heat coming in, negative voltage = heat going out. In other words, the instrument usually guesses at how much the sky is radiating by observing its own losses!
THAT is why, for one thing, an IR satellite telescope has to be super-cooled: otherwise it will detect no external target at all and will merely make incoherent images of the detector’s own output. The same kind of voltage-flow logic is probably at work in IR-thermometers, too. In effect, an IR thermometer responds to colder objects by reporting the radiation that it DOESN’T see.”
You get that luke: a Pyrgeometer reports the radiation it DOESN’T see.
Cohers think he has invalidated the entire international approach to surface energy balance.
When do we expect your Nature paper. Surely it will be soon …
I suggest cohenite goes off now and consults the work of Sir Charles Wheatstone for clues on how not to look up one’s own Khyber in basic measurement terms
yeah, I’ll do that gav; and why don’t you consult your saucer of water, or chicken entrails like the other AGW scientists.
Here’s the non-existent LDR responding to water vapour
http://www.academiaraetica.ch/pdf/symposien/YSC_abstracts_pdf/32_YSC_Wacker.pdf
Here’s the non-existent LDR measured by aircraft
http://rsi.aip.org/resource/1/rsinak/v45/i1/p33_s1?isAuthorized=no
How’s that Nature paper coming Cohenite.
Luke
This instrument (Pyrgeometer) has had a troubled past and past readings are liable to include unacceptable uncertanties.
http://www.arm.gov/publications/proceedings/conf04/extended_abs/ellingson2_rg.pdf
The calibration of the instrument assumes a continuous blackbody spectrum calculated from Stephan Boltzmann equation.
Yet it is then used to measure a line spectrum emitting atmosphere!
So what reliance would you place on the readings?
Very common is the use of a fixed value of emissivity.
Look at the problems encountered using this instrument.
http://www.pyrometer.com/Tech/emissivity.html
The instrument gives more reliable readings at night with a cloudless sky.
Under such conditions there is more radiation leaving the instrument than arriving.
Subtraction calculation from SB equation is required give an indication of the input and so a certain amount of circular reasoning is built in.
For these reasons I am cautious about reaching conclusions based on this instrument.
I would be much more confident of spectroscopic instruments as they involve much less in the way of built in assumptions.
Yes we’re talking clear sky night readings. The existence of downwelling radiation itself. A spectroscopic papers actually above in this thread. Cohenite is not talking “reliability” – he’s talking ANY ! He denies all of the physics involved.
He is personally rewriting all the current day energy balance work including the calibration papers posted above. Against all the research done by the World Radiation Monitoring Center – and the Baseline Radiation Monitoring Network.
Beggars belief ! But hey we’re awaiting his Nature paper !
Bryan I assume you’re up with more modern calibration work on pyrgeometers
http://www.patarnott.com/atms749/pdf/LongWaveIrradianceMeas.pdf
http://www.opticsinfobase.org/abstract.cfm?uri=ao-46-30-7419
Bryan; as I said to cohenite, instrument engineers have long been aware of local environment problems and hence all those bridge arrangements over the decades.
Although I’m no expert on pyrometers v spectrometers re IR, confidence comes directly from practice. To put this in proper perspective you have to go back to a whole lot of considerations –
http://www.arm.gov/publications/proceedings/conf06
Don’t verbal me luke; I never said there was no LWd; what I say is:
1 The methods of measuring LWd have problems
2 The alleged effect of LWd is both exaggerated and not understood.
There’s my paper; get it published like a good chap.
No you didn’t.
What you said above is VERY clear.
“In effect, an IR thermometer responds to colder objects by reporting the radiation that it DOESN’T see.”
You get that luke: a Pyrgeometer reports the radiation it DOESN’T see.”
“I therefore challenge anyone on this site to show me direct evidence of back-radiation. ”
You have provide NIL analysis of the modern literature or knowledge on the subject of your 10:22am.
cohenite’s elitism clearly rivals his “chattering” Michael Thompson after having not done a single physics measurement in his life.
As I said, a little guy hey.
Luke
The history of the Pyrgeometer goes back almost 50 years.
There have been periods of confident claims for their accuracy only to dropped as contradictions emerged.
I would give the recent batch a little more time in actual field measurements before being confident in the results they obtain.
A warm surface emits more radiation of every wavelength than it absorbs.
Using the photon interaction picture to illustrate.
Lets say the warm surface area emits 100 photons of wavelength 15um and absorbs 60 15um.
The result of the radiative interaction is 40 photons of 15um going from hot to cold surface.
This is what we call HEAT.
The radiative effect of the colder surface is to produce a radiative insulation effect.
That’s why sceptics are astonished that the IPCC claim a heating effect of the warmer surface when all it does is to reduce somewhat the heat loss from the warmer surface.
An alternative approach is to use Maxwell’s equations for the situation.
A single Poynting vector with magnitude identical to above from hot to cold is the result.
Which method you use gives the same result summed up by the Clausius statement of the second law.
Heat cannot move from a cold surface to a warmer surface in a complete cycle unless forced by some mechanism using additional work.
No serious scientist is prepared to contradict Clausius.
“Using the photon interaction picture to illustrate.
Lets say the warm surface area emits 100 photons of wavelength 15um and absorbs 60 15um.
The result of the radiative interaction is 40 photons of 15um going from hot to cold surface.
This is what we call HEAT.’
yep agree
“Using the photon interaction picture to illustrate.
Lets say the warm surface area emits 100 photons of wavelength 15um and absorbs 60 15um.
The result of the radiative interaction is 40 photons of 15um going from hot to cold surface.
This is what we call HEAT.’
yep agree”
Good, then you will also agree that the 60 15um is not measured by the Pyrgeometer but deduced/estimated from deducting its own value for 15um radiation and the upward radiation from the total 15um it is ‘receiving’. Could you point to a description in the blizzard of papers and links you have provided which describes a standard value for the Pyrgeometer’s own 15um radiation output?
Now Cohenite – don’t be such a lazy little denialist – you can read the calibration papers above.
What a cop out; its to the knackery for you luke; and take that old grey mare, gav, with you.
O/T
Luke, just like to add that NH human induced CO2 has little impact on SWWA.
No cop out – on a date with a hot chick and need to keep focussed. Am getting ready to get even later.
El Gordo – are you mental?
Quite possibly undiagnosed, just thought you might be interested in looking for carbon sinks? Did you know only 4% of CO2 is produced by the burning of fossil fuels?
Luke,
in all those papers, all you have is an assumption of how the calibration is done correctly?? That is, you assume that you are using the correct value then use the pyrgeometer to validate your assmuption? It is a wonder y’all can walk straight with all the circular logic involved in Climate Science.
(snicker)
Luke,
Oh yeah, didn’t have to reread the lightbulb thingummy. Unlike you I understood the simple, straightforward design the first time through especially as how it was explained so nicely in their marketing literature. You really come up with some sorry stuff there Luke. The fact that you believers want to ascribe unphysical warming rather than decreased cooling to reflection and insulation still doesn’t make it as physics even at grade school level.
Dross KookyKat -don’t worry about the Osram – we’re told here that Eli’s tin foil covered bulb can’t work. Cooler can’t warm hotter scream sceptics on this thread.. It’s does – it’ called NET.
I look forward to your written rebuttal of the World Radiation Center’s work. Calibration paper tabled above.
Then you can explain how all the water balances calculated by energy balances are also wrong.
And why obs seem to match theory. Just one of those great flukes of science eh?.
Klown !
Luke
…….”And why obs seem to match theory. Just one of those great flukes of science eh?.”….
The pyrgeometer is calibrated with the SB equation not with real fixed points as for example a mercury thermometer.
It includes a little offset knob quite unlike a mercury thermometer.
Values are calculated for the night time DLR from line spectra gases to be about the same as continuous warmer spectra from the surface of Earth.
Note CALCULATED and Offset Knob and Circular Reasoning.
Then reconsider why a growing number of sceptics are demanding a systematic review of the conclusions underpinning the so called dangers of AGW.
NO ! The pyrgeometers are calibrated against an absolute sky-scanning radiometer which is calibrated against a reference blackbody source traced to absolute temperature standards.
Obs vs theory are multiple issues. That the pyrgeometer responds to clouds and water vapour. And that energy balances which predict water balances validate.
You guys !
Indeed night-time intercomparisons have shown average pyrgeometer long-wave radiance measurments, an Atmospheric Emitted Radiance Interferometer and model calculations agree to within 1-2 W / m2 with Absolute Sky-scanning Radiometer values.
Luke
…..” The longwave downward irradiance is determined from the thermopile voltage and the dome and body thermistors using the Philipona et al. equation”…….
http://www.pmodwrc.ch/pmod.php?topic=irc
Cohenite,
The LWD does exist, but the problem is from what, and Luke, as well as his cohort, believe it only comes from radiating gases. The problem is that if we assume air is well mixed in terms of Brownian motion, so there are no identifiable separate phases of immiscible gases, the we are dealing a gas called air that contains 0.038 ppmv CO2. This is basically a cube of gas which has a CO2 molecule at its centre surrounded by N2 and O2 molecules on all its sides. Since N2 and O2 don’t absorb LWr then they must reflect it, or disperse it laterally.
Such a molecular cube with one molecule of CO2 at its centre, (I recall calculating the numbers years ago and posted it on the web in some blog sometime), and roughly 1200 molecules of N2 and O2 representing the sides of this imaginary cube, means that for all intents and purposes the CO2 molecule is “invisible” to an observer – its radiation being dispersed by a molecular layer some 600 molecules thick, as it were, between an observer and the object itself.
If you can’t see the CO2 molecule, then any radiation from it is also blocked and unobservable. As N2 and O2 can only have their thermal state increased by collision from an excited radiative molecule, rather than radiation, then CO2 cannot warm N2 and O2 by radiation but by collision via the Brownian motion mechanism. However the CAGW hypothesis asserts that downwelling radiation from a CO2 molecule warms the adjacent O2 and N2 molecules.
It’s the unfamiliarity of working with physical quantities and objects that allows the armchair scientists, those who immerse themselves in thought experiments not derived from physical reality, that results in such bizarre hypotheses like CAGW.
Reading through Luke’s comments here (a tautology if there ever was one), shows that he seems glued to his office chair in front of his computer.
Basically Luke and the CAGW crowd have no physical experience of the physics they reckon they know.
And good to see you are not engaging Luke too much; often arguing with idiots becomes counter-productive since one can’t work out who the idiot is.
Gavin:
“cohenite’s elitism clearly rivals his “chattering” Michael Thompson after having not done a single physics measurement in his life.
As I said, a little guy hey.”
Not bad for an intellectual dwarf.
Clueless drivel.
Sinkers waffle really means “I’m so far out of my depth and being confronted with empirical evidence I think I’ll bulldust a bit”.
Bryan – You’re a mile off. Read some more of his papers.
http://jennifermarohasy.com/blog/2011/02/a-profitable-discharge-of-the-second-law-of-thermodynamics-2/
Luke,
Thanks for the verification that you only know how to quote the climate litany, not understand it. Oh and I threw that post to elicit a reaction from you, and you haven’t disappointed.
Luke,
” It’s does – it’ called NET.”
It is does??
Net warming Luke??
Net decrease in cooling more like!! But thanks for agreeing that the result is NET, that the surface in the example used previously is COOLING by 60 photons quanta even though there are 40 quanta going in from the CO2 which is a level of math I can actually do. 100 out – 40 in = 60 out net!!
As far as your lightbulbs, when I can pump electricity back to the power company by turning on one of those lights I might actually pay attention to something you claim!!
HAHAHAHAHAHAHAHAHAHAHAHHAAH
Luke,
“Indeed night-time intercomparisons have shown average pyrgeometer long-wave radiance measurments, an Atmospheric Emitted Radiance Interferometer and model calculations agree to within 1-2 W / m2 with Absolute Sky-scanning Radiometer values.”
And the net effect of all this downwelling radiation is that water will freeze overnight in 40f ambient lows. NET ain’t squat Luke.
Perhaps, a recall of the basic physics will aid in understanding what occurs in the space between the “two flat, parallel surfaces … facing each other “ maintained at different temperature of which Dr Hertzberg tell us in his leader.
Each surface emits EM waves and at any point of the said space the electric and magnetic fields exist together and fluctuate in the same place; the superposition principle get us the amplitude of each monochromatic vector field E = E1 + E2 and H = H1 + H2. There is also a flow of electrical power (the active component of EM power) and its specific value (W/m2) is obtained by means of vector product of the electrical and magnetic field vectors: dP/dA = E x H (the Poynting vector) that is in practice the spectral radiance I(T,v).
For the plane waves all the vectors are in the same plane and, referring to the simplest case where E1 and E2 have same direction and sense (E1 is greater than E2) whereas H1 and H2 are opposite, we have the amplitudes of field vectors E = E1 + E2, H = H1 – H2 = E1 – E2 (missing the constants), dP/dA = E1^2-E2^2 = I1 – I2. In other words the relationship between the vectors field and the power is not linear but, for the counter-propagating plane waves, is still valid the superposition principle.
We can generalize rotating the couple of vectors E2&H2 with respect to E1&H1, obtaining the same result (that’s a simple exercise of trigonometry).
Then, integrating over the frequencies, we get the ALONE EXISTING FLUX of thermal power I = sigma(T1^4 – T2^4).
Dr Hertzberg, I think your “net flux” could be misleading because it could suggest that the radiative transfer of heat can be treated with the MENTALITY OF ACCOUNTANTS rather than with the RIGOROUS LOGIC OF PHYSICS.
Michele
Dr. Hertzberg handily refutes his own assertion with the equations he quotes. He says
“Thus, the simple use of the Stefan-Boltzmann equation to characterize the emission from a source of radiation as though it depends only on the temperature of the source without considering the temperature of the surroundings that are receiving the radiation, is a misuse of the equation”
…. but then goes on to quote the general expression of the Stefan-Boltzmann equation which does just that. Also handily, he changes the form of the equation so it’s not immediately obvious what he’s done. He says correctly that the flux from the hotter body is sTh^4, and the colder sTc^4, and the net flux I (net) = s (Th^4 – Tc^4 ) which if expressed as I (net) = sTh”4 – sTc^4, is simply the difference between the two fluxes. So there are TWO fluxes not one, the greater from the hotter body, and the lesser from the cooler.
In the case of the earth/atmosphere system, the lesser flux is of course the back radiation which he claims doesn’t exist, yet which has been measured in several careful experiments which refute his unscientific and unsupported claim that “‘Nowhere in the radiation field between the two surfaces is the flux of radiant energy equal to what either of the surfaces would emit if they were facing a complete void at 0K”.
No climate scientist has claimed that greenhouse gasses HEAT the earth, simply that they slow its rate of cooling. The quoted SB equations show that this is the case. The cooler atmosphere reduces the net flux from the surface. If the outgoing energy flow is reduced, while the incoming is maintained, the body (in this case the earth) warms up until radiative flows balance at a higher temperature.
To Mostly Harmless:
The cooler atmosphere radiates energy to the much colder free space, so the one step process becomes a two step process. The net result is essentially the same. So tell me, by how much is the rate of cooling slowed? Is it delayed by a microsecond, a millisecond, one second, an hour, a day, a week, or a month?
I have to insist in my reasoning, underlining that a physical phenomenon must have studied “in itinere” i.e.in its running and not “a posteriori”.
In the space between the two plain plates exists a EM field perturbed and therefore in every point of said space acts a plain EM wave defined in the space-time as
δ²f/ δx² = (1/c²) δ²f/ δt²
whit a general solution
f(x,t) = Asin(kx – ωt) + Bsin(kx + ωt)
a linear combination of two waves (according to superposition principle because the linearity of the problem) that are propagating in opposite directions both perpendicular to the two plates (x axes). That’s, the total effect is found instant by instant in the same place taking into account the boundary effects.
1) If there is the left plate alone, is f(x,t) = Asin(kx – ωt) i.e. a wave propagating rightward.
2) If there is the right plate alone, is f(x,t) = Bsin(kx + ωt) i.e. a wave propagating leftward.
3) If there are both the left and the right plate, and B = A (in the our case the two plates have the same temperature) is f(x,t) = Asin(kx – ωt) + Asin(kx + ωt) = 2Asin(kx)cos(ωt) that is no longer a travelling wave because the position and time dependence have been separated. Therefore, the sum of two counter – propagating waves (of equal amplitude A and frequency) creates a standing wave whit amplitude 2A and there isn’t propagation of energy at any point. It’s wrong to say that the two plates emit and absorb the same flux of heat. Neither A and B emit because between them doesn’t exist any wave that carries energy, all the waves are in “surplace”, the whole space is filled of standing energy.
4) If A < B, then f(x,t) = Asin(kx – ωt) + Asin(kx + ωt)+ (B – A)sin(kx + ωt) = 2Asin(kx)cos(ωt) + (B – A)sin(kx + ωt) i.e. there are created a standing wave of amplitude 2A and a traveling leftward wave (B – A)sin(kx + ωt). Also in this case it’s wrong to say that the two plates emit and absorb. A doesn’t emit and B emit only what the traveling wave carries from B to A.
That’s, the traveling effect of counter wave Asin(kx-ωt) (for us, the back radiation) vanishes on the way and there’s a reduced traveling effect of stronger wave B. Of course, the energy that doesn’t travel isn’t destroyed but simply stored into the space as potential energy of the stationary wave.
Michele
Fuzzy Fuzzy Thinking.
Consider a remnant photon from the big bang. Received and “seen” by a room temperature antenna. The photon has a “temperature” of 3.2K. Energy from cold to hot. Ponder this before opening your mouths. Thank you.
I appreciate Luke’s sanity amid this nonsense. Pyrgeometer measurements validated theoretical calculations of downwelling IR in 1954 (Stern & Schwartzmann, J. Met.), and multiple measurements since have done nothing to change the picture. Arguments that DIR “can’t” exist are pretty bootless in the face of compelling evidence that it does.
Let’s consider this from the point of view of Dr. Hertzberg’s words, quoted near the top of this post:
“The situation is analogous to a simple problem in mechanics. A 1 Kg mass is sitting on a frictionless table and is subjected to a force of 10 Newtons from left to right and simultaneously subjected to a force of 7 Newtons from right to left. Now you are free to calculate what the motion would be if only the 10 Newton force acted on the mass, or if you prefer, you can calculate what the motion would be if only the 7 Newton mass operated on it. But, of course, neither of those calculations describes the real motion, which is that of a 3 Newton force acting from left to right. There is no motion to the left from the weaker force.”
Agreed. But the argument is misapplied to the climate problem. The DIR is analagous to the 7 Newton R-L force. In the analogy it is a real force, just as DIR is a real (and well-measured) phenomenon.
The real motion–the result “of a 3 Newton force acting from left to right”–is analogous not to the DIR, but to the rate of cooling. If you take away the 7 Newton force being applied to the weight in the analogy, the “real motion” will accelerate from that due to a 3 Newton force to that corresponding to a 10 Newton force.
And if you could wipe out the DIR, you would correspondingly increase the rate of cooling. In fact, you would have wiped out the greenhouse effect.
Unfortunately, that only works in imagination, not reality.
The improper quote use of the pyrgeometer and/or room temperature antenna unquestionably shows the total and absolute misunderstanding of the metrology that involves accordingly the coarse misinformation that is done on the thermal radiation.
The aforesaid tools are simple dynamic calorimeter, i.e. devices that measure instantaneously the output electric property induced by the difference between the sensor temperature and the room temperature and hence the heat flux that the sensor and its surroundings exchange with the region optically sighted and framed. Until now, all that is correct for the physics and the metrology.
But here starts the fairy. The heat flux is assumed as NET FLUX due to the balance between the incoming and outgoing long wave radiation flux and so we can compute the incoming flux.
This is neither a physic measure nor a proof. I think it is only a banal trick for to take the low into one’s own hand!
Michele
Comment from: Martin Hertzberg March 1st, 2011 at 1:10 pm
To Mostly Harmless:
The cooler atmosphere radiates energy to the much colder free space, so the one step process becomes a two step process. The net result is essentially the same. So tell me, by how much is the rate of cooling slowed? Is it delayed by a microsecond, a millisecond, one second, an hour, a day, a week, or a month?
I’ve never more read a more nonsensical question posed by someone who claims to be a scientist. A rate is a quantity per unit of time. The question has no meaning.
You appear to think that only “hotter” bodies radiate. If you can show that cooler bodies somehow “impede” radiation from hotter bodies, you’re on your way to a Nobel Prize.