Guest post by Ira Glickstein
The Atmospheric “greenhouse effect” has been analogized to a blanket that insulates the Sun-warmed Earth and slows the rate of heat transmission, thus increasing mean temperatures above what they would be absent “greenhouse gases” (GHGs). Perhaps a better analogy would be an electric blanket that, in addition to its insulating properties, also emits thermal radiation both down and up. A real greenhouse primarily restricts heat escape by preventing convection while the “greenhouse effect” heats the Earth because GHGs absorb outgoing radiative energy and re-emit some of it back towards Earth.
Many thanks to Dave Springer and Jim Folkerts who, in comments to my previous posting Atmospheric Windows, provided links to emission graphs and a textbook “A First Course in Atmospheric Radiation” by Grant Petty, Sundog Publishing Company.
Description of graphic (from bottom to top):
Earth Surface: Warmed by shortwave (~1/2μ) radiation from the Sun, the surface emits upward radiation in the ~7μ, ~10μ, and ~15μ regions of the longwave band. This radiation approximates a smooth “blackbody” curve that peaks at the wavelength corresponding to the surface temperature.
Bottom of the Atmosphere: On its way out to Space, the radiation encounters the Atmosphere, in particular the GHGs, which absorb and re-emit radiation in the ~7μ and ~15μ regions in all directions. Most of the ~10μ radiation is allowed to pass through.
The lower violet/purple curve (adapted from figure 8.1 in Petty and based on measurements from the Tropical Pacific looking UP) indicates how the bottom of the Atmosphere re-emits selected portions back down towards the surface of the Earth. The dashed line represents a “blackbody” curve characteristic of 300ºK (equivalent to 27ºC or 80ºF). Note how the ~7μ and ~15μ regions approximate that curve, while much of the ~10μ region is not re-emitted downward.
“Greenhouse Gases”: The reason for the shape of the downwelling radiation curve is clear when we look at the absorption spectra for the most important GHGs: H2O, H2O, H2O, … H2O, and CO2. (I’ve included multiple H2O’s because water vapor, particularly in the tropical latitudes, is many times more prevalent than carbon dioxide.)
Note that H2O absorbs at up to 100% in the ~7μ region. H2O also absorbs strongly in the ~15μ region, particularly above 20μ, where it reaches 100%. CO2 absorbs at up to 100% in the ~15μ region.
Neither H2O nor CO2 absorb strongly in the ~10μ region.
Since gases tend to re-emit most strongly at the same wavelength region where they absorb, the ~7μ and ~15μ are well-represented, while the ~10μ region is weaker.
Top of the Atmosphere: The upper violet/purple curve (adapted from figure 6.6 in Petty and based on satellite measurements from the Tropical Pacific looking DOWN) indicates how the top of the Atmosphere passes certain portions of radiation from the surface of the Earth out to Space and re-emits selected portions up towards Space. The dashed line represents a “blackbody” curve characteristic of 300ºK. Note that much of the ~10μ region approximates a 295ºK curve while the ~7μ region approximates a cooler 260ºK curve. The ~15μ region is more complicated. Part of it, from about 17μ and up approximates a 260ºK or 270ºK curve, but the region from about 14μ to 17μ has had quite a big bite taken out of it. Note how this bite corresponds roughly with the CO2 absorption spectrum.
What Does This All Mean in Plain Language?
Well, if a piece of blueberry pie has gone missing, and little Johnny has blueberry juice dripping from his mouth and chin, and that is pretty good circumstantial evidence of who took it.
Clearly, the GHGs in the Atmosphere are responsible. H2O has taken its toll in the ~7μ and ~15μ regions, while CO2 has taken its bite in its special part of the ~15μ region. Radiation in the ~10μ region has taken a pretty-much free pass through the Atmosphere.
The top of the Atmosphere curve is mostly due to the lapse rate, where higher levels of the Atmosphere tend to be cooler. The ~10μ region is warmer because it is a view of the surface radiation of the Earth through an almost transparent window. The ~7μ and 15μ regions are cooler because they are radiated from closer to the top of the Atmosphere. The CO2 bite portion of the curve is still cooler because CO2 tends to be better represented at higher altitudes than H2O which is more prevalent towards the bottom.
That is a good explanation, as far as it goes. However, it seems there is something else going on. The ~7μ and ~15μ radiation emitted from the bottom of the Atmosphere is absorbed by the Earth, further warming it, and the Earth, approximating a “blackbody”, re-emits them at a variety of wavelengths, including ~10μ. This additional ~10μ radiation gets a nearly free pass through the Atmosphere and heads out towards Space, which explains why it is better represented in the top of the Atmosphere curve. In addition, some of the radiation due to collisions of energized H2O and CO2 molecules with each other and the N2 (nitrogen), O2 (oxygen) and trace gases, may produce radiation in the ~10μ region which similarly makes its way out to Space without being re-absorbed.
There is less ~15μ radiation emitted from the top of the Atmosphere than entered it from the bottom because some of the ~15μ radiation is transformed into ~10μ radiation during the process of absorption and re-emission by GHGs in the atmosphere and longwave radiation absorbed and re-emitted by the surface of the Earth.
Source Material
My graphic is adapted from two curves from Petty. For clearer presentation, I smoothed them and flipped them horizontally, so wavelength would increase from left to right, as in the diagrams in my previous topics in this series. (Physical Analogy and Atmospheric Windows.)
Here they are in their original form, where the inverse of wavelength (called “wavenumber”) increases from left to right.
Source for the upper section of my graphic.
Top of the Atmosphere from Satellite Over Tropical Pacific.
[Caption from Petty: Fig. 6.6: Example of an actual infrared emission spectrum observed by the Nimbus 4 satellite over a point in the tropical Pacific Ocean. Dashed curves represent blackbody radiances at the indicated temperatures in Kelvin. (IRIS data courtesy of the Goddard EOS Distributed Active Archive Center (DAAC) and instrument team leader Dr. Rudolf A. Hanel.)]
Source for the lower section of my graphic.
Bottom of the Atmosphere from Surface of Tropical Pacific (and, lower curve, from Alaska).
[Caption from Petty: Fig. 8.1 Two examples of measured atmospheric emission spectra as seen from ground level looking up. Planck function curves corresponding to the approximate surface temperature in each case are superimposed (dashed lines). (Data courtesy of Robert Knutson, Space Science and Engineering Center, University of Wisconsin-Madison.)]
The figures originally cited by Dave Springer and Tim Folkerts are based on measurements taken in the Arctic, where there is far less water vapor in the Atmosphere.
[Fig. 8.2 from Petty] (a) Top of the Atmosphere from 20km and (b) Bottom of the Atmosphere from surface in the Arctic. Note that this is similar to the Tropical Pacific, at temperatures that are about 30ºK to 40ºK cooler. The CO2 bite is more well-defined. Also, the bite in the 9.5μ to 10μ area is more apparent. That bite is due to O2 and O3 absorption spectra.
Concluding Comments
This and my previous two postings in this series Physical Analogy and Atmospheric Windows address ONLY the radiative exchange of energy. Other aspects that control the temperature range at the surface of the Earth are at least as important and they include convection (winds, storms, etc.) and precipitation (clouds, rain, snow, etc.) that transfer a great deal of energy from the surface to the higher levels of the Atmosphere.
For those who may have missed my previous posting, here is my Sunlight Energy In = Thermal Energy Out animated graphic that depicts the Atmospheric “greenhouse effect” process in a simlified form.
I plan to do a subsequent posting that looks into the violet and blue boxes in the above graphic and provides insight into the process the photons and molecules go through.
I am sure WUWT readers will find issues with my Emissions Spectra description and graphics. I encourage each of you to make comments, all of which I will read, and some to which I will respond, most likely learning a great deal from you in the process. However, please consider that the main point of this posting, like the previous ones in this series, is to give insight to those WUWT readers, who, like Einstein (and me :^) need a graphic visual before they understand and really accept any mathematical abstraction.
Tim Folkerts says on March 17, 2011 at 6:46 am: “At one level, the answer is simply “IR spectroscopy can measure the EM energy and the result is about 324 W/m^2″”
Yes, OK Tim so 324 W/m² can be measured. – However that does not answer my question which was: “where are these 324 W/m² coming from” I asked because if we assume thermal equilibrium, it cannot be from what is absorbed by the surface and atmosphere as together they receive only: (342 W/m² – 107 W/m² reflected) = 235 W/m² which is 89 W/m² less than 324 W/m², but the same as the 235 W/m² which are leaving at the top of the atmosphere (TOA).
You go on to say in ending your explanation – (thanks for answering, by the way) – : “When looked at from that perspective, losing a few hundred J each second via radiation back to the earth doesn’t seem so amazing.”
No Joules are lost each second via radiation back to the earth Tim. That is not the problem. The problem is that at least 89 W/m² or maybe even the full 324 W/m² must have been created to make up that figure of 324 W/m².
Remember the Kiehl & Trenberth (1997) Energy Flow Plan is the officially accepted explanation for AGW and as long as that is so, it is no good for you, me, Ira or anybody else to attempt to produce a more complicated albeit a much better one. So if you and everybody else accept Kiehl & Trenberth (1997) then ok fair enough. – I may agree with Ira how and why back radiation is done – but something is wrong, and I do not know what – not yet. I have just a few questions for you which I hope you can answer for me, a simple yes or no will do:
1)Can “EM radiation”(EMR) be described as “electromagnetic power transportation” a bit akin to electric conduction except EMR can be transferred through a vacuum and not solid conductors?
2)Is the kinetic energy of an object the energy which it possesses due to its motion?
3)Is Heat a product of work done, say like friction between two or more moving engine components? – Or even friction between moving atoms whether they make up a substance like a gas or even just a single molecule?
4)Can the temperature of an object be describes as a measure of it’s atoms or molecules’ kinetic energy?
Joel Shore says on March 17, 2011 at 1:26 pm : “Consider the geometric sum 1 + 1/2 + 1/4 + 1/8 + 1/16 + 1/32 + …, which, in the infinite limit, converges to the value 2.”
Seen it – considered it – binned it – infinitely!
@ur momisugly Phil & Ira
I apologize for my peremptory response to Ira.
I appreciate that you and Joel and George are a lot more knowledgeable than I am and I think a lot about what you say.
I was impatient with the point that resistance increases with temperature because it didn’t exclude a similar situation where the heat source was something other than an electrial current.
This was the same thing with the reflection, emission business.
In my thinking I had been exchanging absorbers and conductors for the reflector since I figured they should all do the same thing.
O H Dahlsveen says:
Your question reminds me of this riddle: http://answers.yahoo.com/question/index?qid=20061012174256AAnxwnP
The answer is that you are just not thinking about it correctly. There is in fact no more reason that the radiative exchanges between the surface and atmosphere have to be smaller than what is received from the sun than there is reason why what each salesman paid plus what the clerk pocketed has to add up to the original $30 price that he quoted. On Earth, this is somewhat less obvious than, say, on Venus because at least for the Earth the violation of the “law” that you seem to think should exist is not that large.
However, Venus ( http://nssdc.gsfc.nasa.gov/planetary/factsheet/venusfact.html ) has a blackbody temperature of 154 K, meaning that it (including its atmosphere) is absorbing only 65 W/m^2 from the sun (and I believe most of that gets absorbed before reaching the surface). This is lower than earth’s despite Venus’s closer distance to the sun because of its higher albedo. However, its surface temperature of 737 K means that it is radiating over 16000 W/m^2 from its surface! If you lived on Venus, the sort of numbers that you are trying to compare wouldn’t even be close enough to make you ever suppose that the incoming solar radiation somehow sets the limit on what radiative transfers could be within the Venetian system.
O H Dahlsveen,
“Seen it – considered it – binned it – infinitely!”
It is difficult to want to give a more detailed response when you seem consider basic math concepts as trash!
“where are these 324 W/m² coming from”
The air was getting energy several ways from other objects (the surface and the sun)
+ 24 W/m^2 from thermals
+ 78 W/m^2 from evapo-transpiration
+ 350 W/m^2 from IR from the earth
+ 67 W/m^2 from the sun
——————————
= 519 W/m^2
That leaves plenty of energy to supply the 324 W/m^2 of IR energy radiating toward the surface. (With 195 W/m^2 left over to radiate to space)
Its a lot like money exchange among 4 people. I could pay you $350 every month for watching my kids and you could pay me $324 every month for mowing your yard. I don’t need to have been paid $350 from someone else in order to do that. I just have to have some money in my back account to cover the expense temporarily. I would eventually run out of money, but I also get a little allowance from Father Sun of $168, so that keeps me afloat (and allows me to pay you $24 and $78 for other jobs, and to pay $40 to Mr Outer Space) .
You (the atmosphere) get an allowance of $67 from Father Sun. This (plus my $350 + $24 + $78) gives you enough money to pay Mr Outer Space $195 in addition to the $350 you pay me.
The point is that the $324 you pay me does not need to come directly from the “allowance” from the Sun paid us. It does not need to equal $168 at all!
I noticed a couple numbers were wrong above, but the point is correct.
(The 3rd line from the end should be “in addition to the $324 you pay me. )
(The last line should be “It does not need to equal $168 + $67 at all!” )
PS Joel, I was thinking about that same puzzle too!
Joel Shore
…….”That is why it is good to have a whole hierarchy of models…But it is meaningless to object that the simple model is too simple when the evidence from the more complicated models show that in fact the simple model is fine for showing the basic qualitative behavior. Sure, it’s simple…That’s the point.”……
Simple and wrong.
Joel its a big surprise that you are still punting the discredited radiating layer model.
I thought the smart IPCC advocates now favour the more “advanced” proposition;
1. Radiative effects at atmospheric temperatures in the troposphere are small enough to be almost ignored.
That is R W Wood was correct.
2. The dry adiabatic lapse rate is set by Gravitational Field modified by Latent Heat of Vapourisation of Water to determine the actual lapse rate.
3. The real “Greenhouse Effect” happens above the tropopause the so called TOA effect.
The balance of incoming Solar to outgoing Long Wavelength Radiation driving changes to Earth Surface Temperature.
This top to surface rather than surface to top process does seem more plausable.
I said
Kirchoff’s Law does not hold strictly for this situation as significant quantities of thermal energy are passed on to non emitters.
Phil. says
Kirchoff’s Law certainly does apply it’s just that you don’t know what it says!
Emissivity=absorptivity still holds true when collisional deactivation occurs.
My reply
This does not explain why the photon energy at 15um “goes missing” being transformed into translational energy of N2 and O2 which may be for instance returned to surface by conduction or turned into PE by upward convection.
Also much more likely H2O longer wavelengths are now favoured by 30 to 1 numerical ratio and also SB probability consideration.
I said
Some of this energy can come back to CO2 by collision but emission of 15um as we get to higher altitudes becomes increasingly unlikely due to temperature drop.
Phil. says
Wrong it becomes increasingly likely due to the lower collision rate.
My comment
See above and you need to explain yourself in more detail.
How does lower collision rate lead to more CO2 molecules getting enough collision energy to become “active” enough again to emit 15um photon?
I said
A more likely radiative outlet path would be H2O which has several wavelengths >15um available.
This accounts for the large “bite” missing around 15um as shown in the Ian’s satellite “looking down” graphs above.
Phil. says
No that is classic CO2 spectrum, go to MODTRAN and you can reproduce it exactly but not using H2O.
My comment
You go to your computer and you exclude H2O and your point is?
Bryan said:
In what way is it discredited? Is it a simplified model that neglects some things (like convection)? Sure. However, that doesn’t mean it is not still useful…again as part of a hierarchy of models.
It is not like acceptance of the greenhouse effect makes one an IPCC advocate. Roy Spencer, Willis Eschenbach, and Ira Glickstein are far from “IPCC advocates” but they all accept the basic tenets of the atmospheric greenhouse effect.
I haven’t read Wood personally but my impression is that his contribution was showing that a real greenhouse operates primarily by reducing convection rather than reducing outgoing radiation. That just addresses how good the analogy is between a greenhouse and the “greenhouse effect”, not the reality of the effect.
Actually, I would say that these set an upper bound on the lapse rate…I.e., if the lapse rate exceeds these then convection tends to develop and bring the lapse rate back down toward this limiting value. However, I don’t think there is any reason why you can’t have an atmosphere with a lower lapse rate (or even warming with increasing height as in the stratosphere). Why we tend not to have that situation in the troposphere is because it is primarily heated from below (both because solar energy mainly reaches the surface before being absorbed and because greenhouse gases tend to “trap” the terrestrial radiation).
I don’t think that you are correct that the actual action happens above the tropopause. Most of it happens in the mid- and upper-troposphere, e.g., most of the radiation that escapes to space is from that region. The reason for talking about the top-of-the-atmosphere is that looking at the radiative balance there is most fundamental in the sense that the only significant exchange of energy across that boundary is via radiation. Focusing too much, for example, on the radiative effects at the surface misses the fact that convection plays a large role in determining the surface temperature. In that sense, I suppose the radiative shells model can lead to some wrong ideas if taken too far, but that tends to be true of any very simple model. It doesn’t mean the model is not useful for capturing much of the basic physics involved.
Tim Folkerts says on March 17, 2011 at 9:00 pm:
“O H Dahlsveen,
“Seen it – considered it – binned it – infinitely!”
It is difficult to want to give a more detailed response when you seem consider basic math concepts as trash!
“where are these 324 W/m² coming from”
The air was getting energy several ways from other objects (the surface and the sun)
+ 24 W/m^2 from thermals
+ 78 W/m^2 from evapo-transpiration
+ 350 W/m^2 from IR from the earth
+ 67 W/m^2 from the sun
——————————
= 519 W/m^2 “
Look Tim, you think I am stupid just because I binned the old Joel Shore’s “drunken party question” on March 17, 2011 at 1:26 pm where he wrote: “Consider the geometric sum 1 + 1/2 + 1/4 + 1/8 + 1/16 + 1/32 + …, which, in the infinite limit, converges to the value 2.”
For one, yes it converges towards but will not ever get to 2. – That one is as old as the hills. – However the reason for the binning was that it has nothing, as far as I can see, to do with the extra energy created in The Energy Flow Plan. – Enough said?
Your calculation above however is counting energy twice in as much as the “+ 24 W/m^2 from thermals” and the “+ 78 W/m^2 from evapo-transpiration” are two out of three parts coming from the 168 W/m² which the surface absorbs and uses to create thermals and to evaporate water. What the surface has got left is 66 W/m² which it transfers by other means to the atmosphere. (What those ‘other means’ are, the plan does not disclose)
If you look at what leaves at the top of the Atmosphere you will find it is 235 W/m² which is exactly the same as the ‘Earth System’ (ES) absorbs from incoming solar irradiation. – 235 W/m² is all the energy which the ES has absorbed from the Sun. – Your 519 W/m² are not mentioned at all, anywhere on the ‘Energy Flow Plan’ – thank goodness.
Correction, I did not mean Joel Shore is old, his geometric sum question is.
Joel Shore says:
“I haven’t read Wood personally but my impression is that his contribution was showing that a real greenhouse operates primarily by reducing convection rather than reducing outgoing radiation. That just addresses how good the analogy is between a greenhouse and the “greenhouse effect”, not the reality of the effect.”
This is puzzling statement. The so-called ‘greenhouse effect’ assumes that radiation is trapped by IR absorbing gases thus warming the Earth. The very fact that Wood demonstrated that a greenhouse gets warm by trapping air, and that ‘trapping radiation’ had nothing to do with it, shows that the ‘greenhouse effect’ is a complete misnomer. So rather than demonstrating that ‘the analogy is a good one’ it demonstrates quite the opposite.
O H Dahlsveen,
I think we will have to agree to disagree. I have no problem with the surface gaining 492 W/m^2 from various objects and losing 492 W/m^2 to various objects, thereby maintaining a steady temperature. I have no problem with the atmosphere gaining 519 W/m^2 from various objects and losing 519 W/m^2 to various objects, thereby maintaining a steady temperature. There is no contradiction with either the 1st law or the 2nd law of thermodynamics.
Oh Tim, I did not overlook your economics lessen at the end of your last, or previous comment to me but I have needed some more time for that one as when I started to look at it more closely, I began to realize why you think as you do.
You see you are deluding yourself into thinking you have got a monthly income of $ 350 every month. – Your monthly income I am afraid is only the allowance you get from Father Sun. Of that allowance $ 107 are lost ‘in transaction fees’ to a man called Space. $ 67 goes straight into your Atmos IR (Inland Revenue tax) account where it stays until all tax is due. (Life for grown-ups is hard) However Father Sun also pays you $ 168 as ‘cash in hand’ in order to enable you to do various jobs like distilling (he himself makes moonshine too) and grow corn and sugar-beet and generally keep flapping around disturbing the air until next payday when incidentally taxes are also due. – Some friends of yours, The CO2 and H2O people are trying to delay the IR-man’s action by sending some of your allowance back to you but they cannot send it all and because of inflation the money that comes back is only worth half of what it was in the first place. And anyway the H2O people are quite unreliable as they keep flitting about and never stay together in the same place for very long. But having said that, the little bit they can do does help and you may feel a bit of a warm glow of happiness from them. However beware of “Indian-givers” because only when Father Sun is awake and keeps sending you your allowance can they see ”their way clear” to “Loop part of your allowance back to you”
During “Dark Times” when Father Sun is around the other side they say: sorry you are getting colder but we have no options but to take all the extra money back because it will easily be detected at times when no hard cash is being delivered.
So Tim, maybe you will, if you think about it, realizes that some kind of GH Effect (GHE) is possible even if a monthly income of $ 350 every month is not.
————————————————————————————————————————————————————————————————
PS. The moderators are getting kind of “slow and tired” on this post now so I may vanish too. BUT I VILL BE BACK! —— Somewhere else on WUWT – I do hope I have not offended any one as that would not have been the intention. If anyone think I am “B—dy” stupid, it could just be because I am, but don’t worry, it’s not contagious (it does not back–radiate. Beauty can, – but stupidity cannot radiate.)
I said
1. Radiative effects at atmospheric temperatures in the troposphere are small enough to be almost ignored.
That is R W Wood was correct.
Joel Shore commented
I haven’t read Wood personally but my impression is that his contribution was showing that a real greenhouse operates primarily by reducing convection rather than reducing outgoing radiation. That just addresses how good the analogy is between a greenhouse and the “greenhouse effect”, not the reality of the effect.
My reply
R W Wood proved as you say “a real greenhouse operates primarily by reducing convection”
But he also proved that Radiative effects at atmospheric temperatures in the troposphere are small enough to be almost ignored.
If you are in any doubt about this I can point you to further studies.
In a discussion with a well read greenhouse effect believer I asked how high would a glasshouse have to be to show a noticeable effect, he replied 10kilometres.
In effect he had joined the TOA explanation faction making any further discussion of R W Wood redundant.
Oh, how can I leave this place as long as Tim Folkerts and Joel Shore are still about? _
We may not agree upon things, But I do believe that the one who has won the final argument has lost the excitement of the ongoing journey.
Bryan says:
Wood proved no such thing. At best he conjectured. Here is what his 1909 paper ( http://www.tech-know.eu/uploads/Note_on_the_Theory_of_the_Greenhouse.pdf ) said about the subject (it turns out to be very short):
A proof, that is not, by a long shot. (It always amuses me when AGW skeptics will call something a proof if it supports what they want to believe…whereas the would certainly deride the same level of speculation in support of AGW as not even science, let alone a proof.) And, of course, the science of radiation transfer has advanced in the last century so that we can now calculate things and understand how Wood was wrong.
And, yes, the greenhouse effect does depend on the fact that the temperature decreases with height in the troposphere and thus that when the effective emitting layer increases with height as more greenhouse gases are added, this results in the emission occurring from layers that are colder and thus radiate less. (I would say that in a rough sense, the simple shell model does in fact include this, although that model neglects the convective transfers that contribute significantly to determining the vertical temperature structure of the atmosphere.)
>>
O H Dahlsveen says:
March 18, 2011 at 12:30 pm
Your 519 W/m² are not mentioned at all, anywhere on the ‘Energy Flow Plan’ – thank goodness.
<<
In mathematics, 1+1 is the same as 2. The sum of the inputs to the atmosphere is 519 W/m², and the sum of the outputs from the atmosphere is 519 W/m². If that isn’t mentioning 519 W/m², then I can see why you’re having trouble determining where the 324 W/m² is coming from. I ran my model where I started from zero atmosphere energy flux and stepped it through several cycles. I was planning on explaining the cycles, but I think we’re wasting our time.
Jim
Joel Shore
……”And, of course, the science of radiation transfer has advanced in the last century so that we can now calculate things and understand how Wood was wrong.”……..
Joel that is just an assertion give me some proof that as you say “Wood was wrong.”.
Bryan,
The “proof” (really, absolutely overwhelming evidence since I like to avoid the word “proof” outside of mathematics, since science is inductive not deductive) is most simply in the fact that the surface temperature of the earth is well above the “blackbody” temperature necessary for radiative balance between the sun, earth, and space. Additional evidence is provided by looking at the radiation and its spectral distribution both at the earth’s surface and from satellites.
And then there is the theoretical understanding, which ranges from simple models that give one a basic intuition of what is going on to detailed radiative-convective transfer calculations using the measured absorption lines for the various atmospheric components and can be compared to the measured data.
It is totally bizarre that you hang on to a few paragraphs of conjecture from a century-old paper and ignore a century of evidence to the contrary! That’s not science, it is ideological conviction.
Jim Masterson says March 18, 2011 at 9:24 pm:
“In mathematics, 1+1 is the same as 2. The sum of the inputs to the atmosphere is 519 W/m², and the sum of the outputs from the atmosphere is 519 W/m². If that isn’t mentioning 519 W/m², then I can see why you’re having trouble determining where the 324 W/m² is coming from. I ran my model where I started from zero atmosphere energy flux and stepped it through several cycles. I was planning on explaining the cycles, but I think we’re wasting our time.”
If you know that 1+1 is the same as 2 Jim, then why is it so difficult to understand that: 67 + 168 = 519 must be wrong?
The total energy input from the Sun is 342 W/m² of which 107 W/m² is reflected back to space. 342 – 107 = 235 W/m². – If any more than 235 W/m² is returned to space then that must be taken from what is stored in oceans and landmasses and we will have global cooling. That is not only elementary mathematics but elementary science too.
“I began to realize why you think as you do. You see you are deluding yourself into thinking you have got a monthly income of $ 350 every month.”
I begin to realize why you think the way you do — so perhaps we are making progress.
I am under absolutely no delusion that my income is $350. In fact, I am quite sure my net income is (almost) exactly $0. It is the net income that matters.
Returning from the analogy,
*if the surface layer started at some temperature (and hence some thermal energy stored within the surface layer), and the net energy flow is zero (492 W/m^2 in and 492 W/m^2 out) then the surface layer ends with the same thermal energy and hence the same temperature.
*if the atmosphere started at some temperature (and hence some thermal energy stored within the atmosphere), and the net energy flow is zero (519W/m^2 in and 519 W/m^2 out) then the atmosphere ends with the same thermal energy and hence the same temperature.
“The CO2 and H2O people are trying to delay the IR-man’s action by sending some of your allowance back”
This is a wrong interpretation. The atmosphere has its own energy (millions of Joules in each 1 m^2 column of air). It gives 324 W/m^2 of its own energy to the surface. It also gives 195 W/m^2 of its own energy to outer space. So it gives 324 W/m^2 + 195 W/m^2 = 519 W/m^2 net outward energy flow. It would cool off very quickly unless it also got 519 W/m^2 from elsewhere. Since this is the same amount as it receives (some from the sun; some from the surface), then it will not have a net change in energy.
(As a slight correction, the premise of global warming is that the net balance is NOT exactly 0 W/m^2, but rather there is a slight net flux into the atmosphere, leading to a slight increase in temperature over the course of years.)
“If you know that 1+1 is the same as 2 Jim, then why is it so difficult to understand that: 67 + 168 = 519 must be wrong?”
What is this equation?
67 (W/m^2 from the sun to the atmosphere)
+ 168 (W/m^2 from the sun to the surface)
—————————————
= 519 (W/m^2 from the atmosphere to the surface and to outer space)
You are comparing apples to oranges. Of COURSE it is wrong! We all know that.
Conservation of energy says that (as long as temperatures remain constant), then the total energy into some system (for example the atmosphere), must equal the energy out of that system.
You are looking at SOME of the energy into the atmosphere and comparing it to ALL of the energy leaving. (And then throwing in an irrelevant energy flow into some other system.)
Now, if you want to expand your “system” to be the “whole earth” then 67 W/m^2 + 168 W/m^2 =235 W/m^2 would be the power absorbed into that system. You should compare that to the power leaving that system (40 W/m^2 from the surface through the “atmospheric window” and 195 W/m^2 from the atmosphere). This does indeed balance exactly as it should.
Focus on one “system” at a time.
My reply to Tim Folkerts March 19, 2011 at 4:12 pm is:
Tim, I finally think I have worked out how your “defense of The Energy Flow Plan” goes. The order I am doing it in below may not be the same as yours but the principle must be similar.
Let’s start at the bottom or with the Earth’s surface which has got enough energy stored to maintain a steady temperature. It sends 24 W/m² of energy away via thermals, a further 78 W/m² as latent heat plus 390 W/m² as surface radiation. The surface receives 168 W/m² from the Sun and is in need of 324 W/m² to restore balance.
All this energy which adds up to 492 W/m² is directed towards the atmosphere as a whole but 350 W/m² are absorbed by GHGs and 40 W/m² are passed straight back to space through the atmospheric window, which means 452 W/m² mixes in with 67 W/m² which makes a grand total of 519 W/m². The atmosphere then radiates 195 W/m² back to space and 324 W/m² down to the surface via the GHGs. Now both the Surface and the Atmosphere are in equilibrium.
Fine Tim, if what I have written above agrees with you then the plan shows equilibrium and therefore no sign of the dreaded “AGW”. It does however not tell me how the figure of 324 W/m² was arrived at.
Nor does it tell me why GHGs only radiate in one direction (towards the surface and not back to space.) Incidentally the “Outgoing long-wave radiation” is also one-directional. But that’s another story.
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O H Dahlsveen says:
March 19, 2011 at 1:42 pm
If you know that 1+1 is the same as 2 Jim, then why is it so difficult to understand that: 67 + 168 = 519 must be wrong?
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I didn’t say that, so you’re deliberately trying to obfuscate this conversation. As I said previously, this is wasting our time.
I have an inverter that converts 12 VDC to 117 VAC at 60 Hz. I guess you’re going to tell me it doesn’t exist because 12 VDC doesn’t equal 117 VAC. You would be kinda right, because 12 VDC doesn’t equal 117 VAC. Yet I can still use plug-in house-hold items that run on 117 VAC in my 12 VDC based vehicle.
Jim