Guest post by Ira Glickstein
A real greenhouse has windows. So does the Atmospheric “greenhouse effect”. They are similar in that they allow Sunlight in and restrict the outward flow of thermal energy. However, they differ in the mechanism. A real greenhouse primarily restricts heat escape by preventing convection while the “greenhouse effect” heats the Earth because “greenhouse gases” (GHG) absorb outgoing radiative energy and re-emit some of it back towards Earth.
The base graphic is from Wikipedia, with my annotations. There are two main “windows” in the Atmospheric “greenhouse effect”. The first, the Visible Light Window, on the left side of the graphic, allows visible and near-visible light from the Sun to pass through with small losses, and the second, the Longwave Window, on the right, allows the central portion of the longwave radiation band from the Earth to pass through with small losses, while absorbing and re-emitting the left and right portions.
The Visible Light Window
To understand how these Atmospheric windows work, we need to review some basics of so-called “blackbody” radiation. As indicated by the red curve in the graphic, the surface of the Sun is, in effect, at a temperature of 5525ºK (about 9500ºF), and therefore emits radiation with a wavelenth centered around 1/2μ (half a micron which is half a millionth of a meter). Solar light ranges from about 0.1μ to 3μ, covering the ultraviolet (UV), the visible, and the near-infrared (near-IR) bands. Most Sunlight is in the visible band from 0.38μ (which we see as violet) to 0.76μ (which we see as red), which is why our eyes evolved to be sensitive in that range. Sunlight is called “shortwave” radiation because it ranges from fractional microns to a few microns.
As the graphic indicates with the solid red area, about 70 to 75% of the downgoing Solar radiation gets through the Atmosphere, because much of the UV, and some of the visible and near-IR are blocked. (The graphic does not account for the portion of Sunlight that gets through the Atmosphere, and is then reflected back to Space by clouds and other high-albedo surfaces such as ice and white roofs. I will discuss and account for that later in this posting.)
My annotations represent the light that passes through the Visible Light Window as an orange ball with the designation 1/2μ, but please interpret that to include all the visible and near-visible light in the shortwave band.
The Longwave Window
As indicated by the pink, blue, and black curves in the graphic, the Earth is, in effect, at a temperature that ranges between a high of about 310ºK (about 98ºF) and a low of about 210ºK (about -82ºF). The reason for the range is that the temperature varies by season, by day or night, and by latitude. The portion of the Earth at about 310ºK radiates energy towards the Atmosphere at slightly shorter wavelengths than that at about 210ºK, but nearly all Earth-emitted radiation is between 5μ to 30μ, and is centered at about 10μ.
As the graphic indicates with the solid blue area, only 15% to 30% of the upgoing thermal radiation is transmitted through the Atmosphere, because nearly all the radiation in the left portion of the longwave band (from about 5μ to 8μ) and the right portion (from about 13μ to 30μ) is totally absorbed and scattered by GHG, primarily H2O (water vapor) and CO2 (carbon dioxide). Only the radiation near the center (from about 8μ to 13μ) gets a nearly free pass through the Atmosphere.
My annotations represent the thermal radiation from the Earth as a pink pentagon with the designation 7μ for the left-hand portion, a blue diamond 10μ for the center portion, and a dark blue hexagon 15μ for the right-hand portion, but please interpret these symbols to include all the radiation in their respective portions of the longwave band.
Sunlight Energy In = Thermal Energy Out
The graphic is an animated depiction of the Atmospheric “greenhouse effect” process.
On the left side:
(1) Sunlight streams through the Atmosphere towards the surface of the Earth.
(2) A portion of the Sunlight is reflected by clouds and other high-albedo surfaces and heads back through the Atmosphere towards Space. The remainder is absorbed by the Surface of the Earth, warming it.
(3) The reflected portion is lost to Space.
On the right side:
(1) The warmed Earth emits longwave radiation towards the Atmosphere. According to the first graphic, above, this consists of thermal energy in all bands ~7μ, ~10μ, and ~15μ.
(2) The ~10μ portion passes through the Atmosphere with litttle loss. The ~7μ portion gets absorbed, primarily by H2O, and the 15μ portion gets absorbed, primarily by CO2 and H2O. The absorbed radiation heats the H2O and CO2 molecules and, at their higher energy states, they collide with the other molecules that make up the air, mostly nitrogen (N2), oxygen (O2), ozone (O3), and argon (A) and heat them by something like conduction. The molecules in the heated air emit radiation in random directions at all bands (~7μ, ~10μ, and ~15μ). The ~10μ photons pass, nearly unimpeded, in whatever direction they happen to be emitted, some going towards Space and some towards Earth. The ~7μ and ~15μ photons go off in all directions until they run into an H2O or CO2 molecule, and repeat the absorption and re-emittance process, or until they emerge from the Atmosphere or hit the surface of the Earth.
(3) The ~10μ photons that got a free-pass from the Earth through the Atmosphere emerge and their energy is lost to Space. The ~10μ photons generated by the heating of the air emerge from the top of the Atmosphere and their energy is lost to Space, or they impact the surface of the Earth and are re-absorbed. The ~7μ and ~15μ generated by the heating of the air also emerge from the top or bottom of the Atmosphere, but there are fewer of them because they keep getting absorbed and re-emitted, each time with some transfered to the central ~10μ portion of the longwave band.
The symbols 1/2μ, 7μ, 10μ, and 15μ represent quanties of photon energy, averaged over the day and night and the seasons. Of course, Sunlight is available for only half the day and less of it falls on each square meter of surface near the poles than near the equator. Thermal radiation emitted by the Earth also varies by day and night, season, local cloud cover that blocks Sunlight, local albedo, and other factors. The graphic is designed to provide some insight into the Atmospheric “greenhouse effect”.
Conclusions
Even though estimates of climate sensitivity to doubling of CO2 are most likely way over-estimated by the official climate Team, it is a scientific truth that GHGs, mainly H2O but also CO2 and others, play an important role in warming the Earth via the Atmospheric “greenhouse effect”.
This and my previous posting in this series 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 that transfer a great deal of energy from the surface to the higher levels of the Atmosphere.
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 Atmospheric Windows 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 one 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.
Ira,
I see something completely different in those two graphs than you do, and frankly what I see makes of alot more sense. At least to me it does.
First things first. The description of these graphs say these are spectra of the atmosphere on a clear DAY in the arctic – get that? – DAY. Why the arctic? To minimize the effects that pesky water contributes to these spectra over most of the rest of the planet. So here is what is see. Not illustrated, but easy to visualize is the black body curve of what is creating both of these spectra – THE SUN – you just have to imagine another spectrum of the illumination source exactly following the top dashed line.
Now what is the back drop for both of the spectra? Well for the ‘look down’ spectrum it is probably a snowy landscape right at 273K. What would you expect to see if there were no atmosphere? The spectrum of a BB radiator at 273K. For most of the graph where the sun isn’t exciting atmospheric gas molecules that is what you see. For the ‘look up’ scene the back drop is the the cold black of space. Were it not for the excited atmospheric molecules sitting between the detector and this back drop we would just see pretty much a flat line.
So now throw in the sun, which is most likely illuminating whatever atmospheric gases are present from the side, (it is after all the Arctic), and you get the two spectra. From 20 Km we don’t see a large water signature radiating back out to space – which tells me there’s very little water vapor in the atmosphere in this scenario to be excited . And low and behold the lack of much water creates a window in which a large portion of the what would normally be the dominant absorber and radiator – water – is missing. In the visible spectrum you see a whole lot of electronic excitation states from all of the gases, and you clearly see one of CO2’s signature excitation bands – the 7μ mode being excited by THE SUN. You also see the unique line spectrum of ozone right in the middle of that 10 μ band.
Starting right about 12 μ both graphs deteriorate into what looks like a much colder thermalization induced BB radiator for the whole of the atmospheric gas milieux. I’m sorry, but I do NOT see CO2’s signature absorption or emission peak at it’s most dominant, highest extinction coefficient band – 15 μ. Both graphs in this region show the same broad spectrum illumination characteristic of a weak BB radiator where every gas is in thermal equilibrium with the milieux, and none are particularly absorbing or emiting any characteristic spectra, even though one of them is a strong absorber.
So what would convince me that CO2 actually plays the dominant role you claim? It is quite simple. I need to see a third and fourth graph of this same scenario WITHOUT solar illumination. It should be entirely possible to create a wide area BB radiator that ONLY radiates a black body spectrum at 273 K in the Arctic (ie no convection heating of the atmosphere over this cold light source). If the upward looking graph for this scenario shows 7μ, and 15 μ peaks radiating down to the surface, from this upward illuminating cold light source, and if the downward looking graph shows missing bands in those same regions when viewing the same light source then yes I will have to conclude that CO2 is contributing a significant ‘greenhouse’ effect. Why aren’t these most crucial graphs illustrated for this same scenario? I wouldn’t be surprised if they were taken, but since they showed NO CO2 signatures, they were sent to the circular file. They told the wrong story.
Again, I believe that CO2 does play a minor role to keep our atmosphere warm, but I will reiterate, WATER DOMINATES when it comes to maintaining our atmosphere at a stable temperature. Water isn’t just a passive radiative player either. It is an active phase changing player storing and redistributing both heat energy and cooling all over the globe in very short time scales. Whereas CO2 is necessary in the photosynthesis cycle and therefore an increase can only help feed the world.
Not going to spend much time making these word pretty, probably too late for anyone to read it.
I feel like I was partly to blame to start this very lengthy discussion on N2 & O2’s possibility to absorb and emit photons in out atmosphere but I do like the truth to be told if it is real no matter how tiny it’s effect. The fact that it is tiny can then be added as a caveat in any discussion.
But let’s for a minute assume that they do. I’ll pick O2 at it’s 5.5-7.4 µm (1345-1820 cm-1) that HITRAN documentation claims. What is it’s effect on this whole discussion? I say very little and not just because that span of frequencies radiance is a small portion of the BB radiation from the ground at 288K, but instead that those photons within that range would not go but a few centimeters (swag) before being absorbed. There are just so many O2 molecules at this pressure of one atmosphere.
And what if an O2 molecule a meter off of the ground did radiate? That photon once again would not travel far to find another O2 (matching absorption/emission frequencies) to absorb it and when absorbed it would have a high probability just to be thermalized as any of the other types of molecules in our atmosphere.
If it was N2 this process would be even worse. N2 would not travel even one centimeter (swag) before recapture. So would this be “back radiation” from these photons if they have no chance to reach the ground unless they are emitted below your ankles? Not to me!
Well what of H2O? Out of every 2500 molecules in the atmosphere there are 60 water molecules (per Wikipedia @ur momisugly 2.5%). Nitrogen has 1950 of these 2500 and oxygen has 525 of them so water molecule emitted photons would travel even further before capture by another H2O molecule. Of every 2500 molecules there is one CO2 and I have read that CO2 emitted photons travel no more that 10 meters before capture near the ground so water might travel something like 50 centimeters to just be mainly thermalized. CO2 traveling the furthest.
If all of the above is realistic then I don’t know if anyone else gets very curious feeling, but I do. Where is all of this tremendous “back radiation”? Really, from where? If all radiation at 100 meters of altitude high has no chance of hitting the ground, WUWT? The only place this process falls apart is near the TOA and above as even LTE fails and the photons have little chance of ever being captured.
Well, now I have to be honest and admit that this has always been the way I have viewed the atmosphere, right… no back radiation of any meaningful amount. But these small jumps in radiation help to one, equalize, and two, to speed the movement of heat upward for the deck is stacked (probability) in that direction as all molecules get further and further apart so the capture distances get longer and longer.
I have brought it up every few month’s here just to have no one ever acknowledge that they at least understood this view of the process whether they believed it was correct or not. Since everyone has been so intent on this very subject here, I just had to try one last time.
Looking just a bit deeper you would find this whole thought process parallel’s that of
Dr. Tom Vonk’s description of thermalization in this post: http://wattsupwiththat.com/2010/08/05/co2-heats-the-atmosphere-a-counter-view/
(I feel like the fellow in the movie “I’m Legend”)… Anyone out there? Anyone? ☺
to Al Tekhasski, and Wayne and any others
My purpose with Phil and some of the others was simply to point out that when certain phenomena are measured in isolation, such as using his FTIR to measure absorption, the results can easily mislead the unwary when they try to apply the results to the ‘whole’, the real world.
And it is the ‘whole’ that concerns us, not the bits and pieces.
Personally, I don’t need any ‘model’ to see a very good picture of the ‘whole’.
To me, the simple actual surface temperature records from Amundsen-Scott, Vostok, and other interior Antarctic stations provide the best possible data out there, even better than satellite data. And I don’t mean any ice core data, either. That’s just a load of speculation.
I am talking about the real thermometer readings from 1957 to present. No speculation.
The first reason the interior Antarctic data is important is because CO2 has also been measured there. And CO2 there has risen from 1957 onwards tracking the rise noted at Mauna Loa and other stations.
The second reason the interior Antarctic data is important is because radiational heat transfer through the atmosphere is more dominant there than any other place on earth. Period.
The third reason the interior Antarctic data is important is because there is NOTHING on earth that can drive those surface air temperatures down, except a decrease in the energy content of the atmosphere, OR direct radiational heat transfer from the surface to outer space. You can take your pick there, it doesn’t matter. It is the SUMMATION that is important. And that summation is exactly what the thermometer readings handily give us.
There are lots of local effects, winds, moisture, UHI, etc that can drive the temperature up temporarily, but NONE of them can drive it DOWN.
The fourth reason the interior Antarctic data is important is because you need only to look at the yearly low temperatures recorded. Each of those low temperature data points are the clearest signals (least amount of local noise) of any physical measurement that is possible on earth, or from a satellite in space. Period.
AND THERE HAS BEEN NO HEATING trend whatsoever due to the increase in CO2 in the atmosphere above central Antarctica from 1957 to date. In fact, it appears to be cooling slightly.
It’s that simple.
Domenic, my admiration for your intellect grows and grows. Thank you.
The concept of “back radiation” nonsense. It confuses cause and effect in a very fundamental way. Radiation is caused by delta-T, not the other way around. A passive material does not “back radiate”. Conduction, convection and radiation always work in the same direction (unless outside work is used)–they are mechanisms for transferring heat energy from hot to cold objects. Just because a formula can be used to describe a process does not mean mother nature will allow you to reverse the equation and use the effect to create the cause.
Domenic says:
March 5, 2011 at 5:24 am
to Al Tekhasski, and Wayne and any others
My purpose with Phil and some of the others was simply to point out that when certain phenomena are measured in isolation, such as using his FTIR to measure absorption, the results can easily mislead the unwary when they try to apply the results to the ‘whole’, the real world.
And you achieve that purpose by making untrue statements about those properties? Seems a weird way to to it, I guess you’re admitting now that what you said about the absorption/emission of N2 and O2 in the IR was wrong?
Nice way to change the subject though.
Don V says:
March 5, 2011 at 2:18 am
In the visible spectrum you see a whole lot of electronic excitation states from all of the gases, and you clearly see one of CO2′s signature excitation bands – the 7μ mode being excited by THE SUN. You also see the unique line spectrum of ozone right in the middle of that 10 μ band.
The 7μm band would have to be excited by IR not by the sun.
Starting right about 12 μ both graphs deteriorate into what looks like a much colder thermalization induced BB radiator for the whole of the atmospheric gas milieux. I’m sorry, but I do NOT see CO2′s signature absorption or emission peak at it’s most dominant, highest extinction coefficient band – 15 μ. Both graphs in this region show the same broad spectrum illumination characteristic of a weak BB radiator where every gas is in thermal equilibrium with the milieux, and none are particularly absorbing or emiting any characteristic spectra, even though one of them is a strong absorber.
What you’re looking at is the low resolution spectrum of CO2, see below for a calculated spectrum for the subarctic atmosphere with a surface temperature of 267K
http://i302.photobucket.com/albums/nn107/Sprintstar400/rad05093716.gif
Ken Coffman says: March 5, 2011 at 6:44 am
The concept of “back radiation” nonsense. It confuses cause and effect in a very fundamental way. Radiation is caused by delta-T, not the other way around.
I at least partially agree — the term “back”radiation can indeed a bit confusing and makes it seem “special” when there is nothing fundamentally special about it. The term “radiation” would suffice perfectly well.
However, radiation is caused by Temperature, not by Delta-T.
P= A (epsilon) (sigma) T^4.
There is no need to mention other objects in the area or what caused the object to be warm.
* The sun at ~ 5700 K radiates the same whether or not the earth was here to receive it. The temperature of the earth does not affect the black body radiation of the the sun.
* a patch of ground radiates the way it radiates based on its temperature and emissivity. If the patch of ground is at 300 K, it will radiate as a 300 K black body (modified slightly by its emissivity which is slightly less than 1 for applicable). It doesn’t matter if the land was heated to 300 K by the sun or the atmosphere or an electric heater.
* the atmosphere radiates the way it radiates based on its temperature and emissivity. The emissivity of N2 & O2 is practically zero across the applicable IR spectrum. The emissivity of CO2 and H2O and other GHGs is NOT always close to zero, but instead there are broad bands where the emissivity is not close to 1 (ie where these molecules can and do absorb and emit IR effectively given sufficient path length thru the molecules).
The GHGs radiate in all directions. Some radiation heads up; some heads down; some heads east, some heads west ….
“Back radiation” from the atmosphere is simply that part of the radiation that happens to be heading back toward the earth. It is still just regular old radiation as described by the S-B Law – the same as the radiation heading any other direction. The only special thing is the direction, not the fundamental nature of the radiation.
Don V says:
March 5, 2011 at 2:18 am
So what would convince me that CO2 actually plays the dominant role you claim? It is quite simple. I need to see a third and fourth graph of this same scenario WITHOUT solar illumination. It should be entirely possible to create a wide area BB radiator that ONLY radiates a black body spectrum at 273 K in the Arctic (ie no convection heating of the atmosphere over this cold light source). If the upward looking graph for this scenario shows 7μ, and 15 μ peaks radiating down to the surface, from this upward illuminating cold light source, and if the downward looking graph shows missing bands in those same regions when viewing the same light source then yes I will have to conclude that CO2 is contributing a significant ‘greenhouse’ effect. Why aren’t these most crucial graphs illustrated for this same scenario? I wouldn’t be surprised if they were taken, but since they showed NO CO2 signatures, they were sent to the circular file. They told the wrong story.
Well they would only have importance to you because you have a flawed view of how these gases are excited into the higher energy levels in order to emit. They are not excited by short wave solar radiation and trickle down the energy levels until they emit in the IR (your model). Since no one actually thinks that then the significance of the night-time data doesn’t occur. Your snide suggestion that because you haven’t seen them that the evil scientist trashed them is beneath contempt. Since seeing such a graph would convince you of the error of your ways I suggest you look at fig 8 below.
http://www.osti.gov/bridge/purl.cover.jsp;jsessionid=6CB3171E19F77B57AEA27EB269BFEAC4?purl=/957049-3J26t7/
Hi Ken,
Thank you. That was very kind of you.
Whatever intellect I have, and its not that great, I would gladly trade some of it for more intuitive abilities.
It’s the intuitive abilities that let us go beyond ourselves and catch glimpses of the ‘whole’. The intellect just seems to tag along for the ride, telling the great stories.
But I suspect you already know that. It’s probably what pushed you into becoming a publisher!
Cheers,
Domenic
to Phil
Nope.
Ken Coffman says:
March 5, 2011 at 6:44 am
The concept of “back radiation” [is] nonsense. It confuses cause and effect in a very fundamental way. Radiation is caused by delta-T, not the other way around. A passive material does not “back radiate”. Conduction, convection and radiation always work in the same direction (unless outside work is used)–they are mechanisms for transferring heat energy from hot to cold objects. Just because a formula can be used to describe a process does not mean mother nature will allow you to reverse the equation and use the effect to create the cause.
You make an interesting point. I agree that man’s theories (mathematical characterization) of how nature works have no effect on how mother nature actually works. As someone once said: “It’s just a matter of time before any theory is disproved.” However, this does not mean that man should abandon the use of theories. Man has benefited from many “tools” he developed using incorrect theories.
In this light, I take exception to your statement: The concept of “back radiation” [is] nonsense. Maybe the word “back” is misleading, but Planck’s blackbody radiation law has proven useful to man’s understanding of the universe. Planck’s blackbody radiation law characterizes the properties (spectral distribution, directionality, magnitude) of electromagnetic radiation emitted from a planar differential area on the surface of a blackbody at a known temperature. The spectral distribution is characterized by specifying as a function of frequency the amount of radiated energy per unit frequency. The directionality is characterized by expressing the amount of radiation emitted into a differential solid angle and includes the factor of the COSINE of the angle between the normal to the plane of the differential area …and… the direction of the differential solid angle. The magnitude is characterized by some constants and the fourth power of the temperature. This formula seems to work experimentally, and as I understand it, can be derived from quantum mechanics principles. In fact, I read somewhere that one of the great accomplishments of quantum mechanics was to provide the theoretical basis for the radiation law, which up to then had been verified experimentally, but which seemed to contradict prevailing theory.
Planck’s law does not differentiate between the surfaces of “active” and “passive” (I prefer the term “inert”) objects–it quantifies the properties of electromagnetic radiation emitted from a surface. As such, it can be applied to both an isolated object and multiple disjoint objects. For example, I believe the temperature of a passive blackbody object placed in the vicinity of an active blackbody object will affect the temperature of the active object. Specifically, consider an isolated, active (constant source of thermal energy), spherical, blackbody object whose surface temperature is everywhere the same. Once the rate that energy leaves the object via radiation equals the rate at which thermal internal energy is being generated, the temperature of the surface of the object will cease to change and settle at a fixed value. If a passive blackbody sphere is placed in the vicinity of the active sphere, the presence of the passive sphere will cause the steady-state temperature of the active sphere to change. I hope you agree; but I await your response. For the moment, however, let’s assume the temperature of the active sphere does change; and we want to compute the “new” temperature of the active sphere surface. If we assume a uniform surface temperature distribution for both spheres, Planck’s law can be used to relatively easily compute both the “new” temperature of the active sphere surface and the temperature of the passive sphere surface. I strongly believe that the surface temperature of the passive sphere will be less than the surface temperature of the active sphere; and energy will flow via radiation from the active to the passive sphere. Using Planck’s “model”, the rate of energy leaving the active sphere is the same IN ALL DIRECTIONS because the surface area of the active sphere is assumed to be uniform. Similarly, the rate of energy leaving the passive sphere is the same IN ALL DIRECTIONS. As I understand your thinking, you would argue that the rate energy leaves an object in the direction of another object is a function of the temperature difference between the objects, and as such the rate energy leaves the active sphere in the direction of cold space differs from the rate energy leaves the active sphere in the direction of the passive sphere. I have difficulty adopting this line of reasoning. Here’s why. Suppose you have a star, like our sun, whose internal energy source is for all practical purposes constant; and although other matter exists in the universe, that star is the only star. At some time, matter many light years from our star coalesces into a second star. Does the existence of the newly formed star affect the amount of radiation from the original star in the direction of the newly formed star? And if so, when? That is, is the amount of radiation affected at the time the star is created? Or is it affected only when the light from the newly formed star reaches the original star? Furthermore, if the newly formed star is at a higher temperature than the original star, does this mean that the original star ceases radiating in the direction of the newly formed star? This may in fact be the way nature works; but if so the process of analyzing the temperatures of a multi-object system becomes infinitely more complex than a model that quantifies the radiations from the individual objects and defines the “heat” between any two objects to be difference between the two radiation rates.
One final point. You said A passive material does not “back radiate”. OK. Suppose in the passive object I place a small source of thermal energy–small in the sense that it produces a small increase in the temperature of the passive object. Has the passive object now become an active object? Surely the temperature increase of the “passive” object will have an effect on the temperatures of both the passive object and the originally active object. How do we quantify the rate, if any, that the energy from this small source of energy is radiated to the original active object? Is this effect (a) radiation, (b) backradiation, or (c) something else?
Bottom line, I think we’re on the same side in that the statement that “backradiation warms the surface of the active object” is incorrect. ALL warming comes from the active object’s internal thermal energy source. However, I think the concept of individual object radiation, whether it’s backradiation, forward radiation, or just plain radiation, is a useful way to characterize radiative energy transfer.
Vince Causey says:
March 3, 2011 at 11:33 am
Re Myrrh says: “So, radiation is included, not just conduction, which means that it is impossible for a cooler molecule to transfer heat to a hotter one because that violate the 2nd Law.”
You based this on the following definition of the 2nd law: “”When two isolated systems in separate but nearby regions of space, each in thermodynamic equilibrium in itslef, but not in equilibrium with each other t first, are at some time allowed to interact, breaking the isolation that separates the two systems, and they exchange matter or energy, they will eventually reach a mutual thermodynamic equilibrium.”
Myrhh, you have read the 2nd law and have drawn the wrong conclusion. The 2nd law considers “two isolated systems in separate but nearby space, not in equilibrium with each other,” as you have pointed out. It then says that when they are allowed to interact they “exchange matter or energy..” This is the crucial point THEY ie both bodies – hotter and cooler – exchange energy. But the crucial conclusion from the 2nd law, is that as a result they “will eventually reach a mutual equilibrium.” This is because the hotter body is transmitting at a far greater flux density than the cooler body.
The GHG hypothesis describes a cooler atmosphere radiating to a warmer surface, which some, including you, say is impossible because it violates the 2nd law. But we have seen that the 2nd law says both bodies will exchange energy, and they will eventually equilibriate – if they are isolated systems. If the Earth was not continually recharged with energy from the sun, it would cool down to the temperature of the atmosphere, and both of them would continue to cool as they equilibriate with space.
First of all, apologies for not getting back to you earlier.
You say I’m misunderstanding the 2nd Law because of not fully appreciating the phrase “THEY exchange matter or energy”. This is the crux of the matter, and why I say this is where AGW is confused, to the point where as above shortwave radiation is believed to ‘be thermal energy heating the Earth’, because this is how the ‘statistical’ has justified ‘its method ‘, by looking at energy exchange out of context of heat. It then has the temerity to say the 2nd Law doesn’t apply to it… Because of this it is assumed that the energy exchange from the cooler can happen from the hotter and in the exchange a ‘net’ result then conforms to the LAW, BUT, the Law says it can’t.
There are two important things here. The Law as it stands CANNOT be broken. If a hypothesis, such as the cooler radiates to the hotter thereby heating it because etc. and so claiming the Law doesn’t apply in its particular instance, then THIS IS INCREDIBLY IMPORTANT TO SCIENTIFIC UNDERSTANDING – BECAUSE IF PROVEN IT FALSIFIES THE LAW!!
Go collect your Nobel prizes for Science!
I can’t see any recognition of the importance of this from those arguing such a thing can happen.. because there’s zilch understanding of what they’re saying by those saying it.
AS THE LAW STANDS – this applies to all energy and matter states, on every level. It specifies energy and it is energy we are discussing, Electromagnetic.
Now my understanding. I have not read anywhere, and it is nowhere stated in Real Science, that heat can flow from the cooler to the hotter. Investigating this, such claims as Ira has made here, that shortwave Solar is thermal and heats the Earth and is what we feel as heat, and elsewhere, that UV penetrates deeper than Visible that penetrates deeper than Thermal IR, etc., I have found where the error has occurred. How well I can explain this, well, obviously not very well since there’s a difficulty following my explanation, or you’re all just so sure of yourselves that you think you can dismiss what I say because I don’t come from a science background, whatever.
But thank you for engaging with me, Ira still continues refusing to answer me even after I have shown him a NASA page showing his premise is utter nonsense, so I will have one more go at this.
That LAW is not broken, it stands. It must apply to all energy states if it applies to any. That’s why it is a LAW, it applies in all cases.
So, what is happening at the meeting place of the two previously isolated systems? Whatever it is it CANNOT be that AT ANY TIME in the exchange until equilibrium is reached that the Cooler is Heating the Warmer. Otherwise the 2nd Law is broken.
I say that whatever energy is exchanged the energy of the cooler cannot be heating the warmer, and as this is Solar and Thermal radiation we’re talking about, whatever radiation is being transferred from the cooler to the hotter it cannot have the effect of adding heat to it.
I have shown that not all IR is Thermal. Solar, Visible and the two shortwave either side, UV and Near IR, are not felt but if intense enough they can burn the cooler matter, but they cannot add heat to warmer matter. If, there is any exchange of energy from the cooler to the warmer, it will not energy capable of adding heat.
If the cooler is hot then its ability to transfer any of that heat to a hotter is non-existant. Heat ALWAYS flows from Hotter to Colder. It may well be transferring cool Near IR as photons, but these will be INCAPABLE of adding heat to the hotter.
That is the only way to read this LAW. If you have a hypothesis that doesn’t fit it exactly then the hypothesis is junk.
As I tried to explain above, that the ‘statistical approach’ to science has come up with something that they think explains this imaginary ‘net transfer’, doesn’t mean that is has any actual basis in reality. Average ISN’T real, Ideal, as in gas, ISN’T real, these are mathematical constructs useful in some calculations, but, to use them and think of them as REAL is absurd.
This idea of the statistical net exchange is what has confused AGW supporters here, they think it is real. They have no concept of the difference in Science between the terms REAL and IMAGINARY, as useful as imaginary can be in context for some calculations if one doesn’t understand that it isn’t referring to real world then all kinds of imaginary conclusions can be claimed, that have no basis in reality. And they can’t tell the difference and so can’t see what utter codswollop they’re saying.
If there’s an average of 400 ppm of Carbon Dioxide in the atmosphere, does it mean that everywhere in every discrete portion of the atmosphere at every time? Of course AGW says, it is well mixed… If the rainfall in your home county is 10″ average a year, does it mean that it is 10″ every day and in every place? Average is imaginary. So, Ideal is imaginary in describing gases, there is no such thing as an Ideal gas in real life, all gases are Real. Look up the difference, see how AGW has used ideas from Ideal gas laws and applied them out of context to Real CO2 in the atmosphere.
If AGW supporters understood that not all radiation is thermal and understood the difference between reflective and absorptive, or understood that the 2nd Law cannot be broken in any of its parts, or that ideal gas laws do not describe how CO2 behaves in the atmosphere, they would also see that the methodology behind this ‘net transfer obeys 2ndLaw’ is nonsense. Work out a better methodology sticking to the 2nd Law and sticking to actual Real properties of radiation and gases or continue living in AGW created cloud cuckoo land where Solar energies are thermal and CO2 acts like an Ideal gas with no volume and no weight and no etc.
In other words, the explanation for ‘net transfer’ is a load of bull.
And so many here think themselves scientists..
Domenic wrote:
“My purpose with Phil and some of the others was simply to point out that when certain phenomena are measured in isolation, such as using his FTIR to measure absorption, the results can easily mislead the unwary when they try to apply the results to the ‘whole’, the real world.”
I thoroughly agree. It’s frustrating that more research on the atmosphere as a whole cannot easily be located. I was searching for a word late last night to describe the radiation interaction in the lower troposphere and it finally came to me, “resonance”. That is the term that should replace “back radiation” in that sense at low altitudes. At high altitude it is next impossible for any radiation emitted from any molecule to go lower but moving upward is nearly unimpeded.
Al Tekhasski:
I really appreciate that paper on O2-O2, N2-O2 interactions, etc. You just intuitively feel that is real and must be occurring and it’s great to get some real empirical backup on that thought. It’s going to take a long time for this whole puzzle to be solved. Phil likes to marginalize such small effects because they are not large like H2O’s and CO2’s emissivities by also there is hugely more O2 and N2 there, so the overall effect on the total energy flows is not what it seems when looking at CO2 in a cylinder in a lab. We all seem to get that.
Both:
Wish someone would read my last comment and tell me where I might be wrong; I’m not very intuitively versed on the scales of radiation ‘path lengths’ and ‘optical path depths’. I feel I might have some scales incorrect and of course the emissivities must also always play into those interactions and lengths. See: March 5, 2011 at 3:10 am. It was quickly written and I missed a whole lot of needed commas.
Hello Reed. The way I see it, the radiation between a hot and a cold object already includes the net radiation intensity described by the delta-T. So, if we add in back radiation as the cold object warms, then this is “double accounting”. Regardless, the only thing the cold (passive or inert) object can do is modulate the cooling of the warm (heated) object. If there is perfect coupling between the objects, the most that can happen is both objects arrive at the same temperature…but never will the heated object be warmer than it was. Once they are the same temperature, then the net radiotion is zero and no energy is exchanged. This is the key contradiction of the global warming theory…given this analysis, how can we get higher and higher peak temperatures and/or higher and higher average temperatures? I thnketh not.
Myrrh says:
March 5, 2011 at 1:03 pm
Vince Causey says:
March 3, 2011 at 11:33 am
In other words, the explanation for ‘net transfer’ is a load of bull.
Myrrh, I think your characterization is a bit strong. For example, consider two stars (A and B) on opposite sides of a galaxy that are formed simultaneously (simultaneous in someone’s reference frame). Before the light (radiation) from star A has time to propagate to star B (and vice versa), isn’t it reasonable to say that star A is radiating a quantifiable amount of energy per unit time in the direction of star B, and vice versa? Does the arrival of the light at star A from star B alter/nullify this statement? I would say no. I believe “heat” is the exchange of thermal energy between objects. By this definition, for the time interval between the birth of the stars and arrival of the energy from the distant star, no heat is being exchanged. Energy still leaves each star; it just hasn’t become “heat” in the sense that “heat” is the exchange of thermal energy between objects. After the arrival of the energy from the distant star, “heat” exists. I believe the amount of heat is the difference between the energy rates in the directions of the opposing stars. The term “net” applies to the combined total (sum and difference) of all components. In this sense, “net radiation” is equal to heat; and the heat (net radiation) will be in the direction of the star at the higher temperature to the star at the lower temperature.
When discussing radiative thermal energy exchange between two objects, it may very well be more appropriate to talk about the heat between objects and not mention the rate thermal energy leaves each object in the direction of the other object. However, such an approach precludes the use of Planck’s blackbody radiation law, which from a “rate” perspective describes only the rate that energy leaves a surface in a specified direction. In the absence of conduction and convection, I believe the heat exchanged between two blackbody objects can be determined by computing the difference (net) between (1) the rate radiative energy leaves object A in the direction of object B and (2) the rate radiative energy leaves object B in the direction of object A. If true, then a discussion of the “net rate of energy transfer” isn’t “bull”; it is just one way of determining the heat between objects; and hence can be used in part to determine the surface temperatures of objects in a multi-object system.
Myrrh,
I have one very simple request of you. Define precisely what you mean by “heat”. Until everyone agrees on the definition of this critical yet subtle idea, all the discussion in the world (any any side of the issues being discussed here) will be pointless.
Myrrh says:
March 5, 2011 at 1:03 pm
You say I’m misunderstanding the 2nd Law because of not fully appreciating the phrase “THEY exchange matter or energy”. This is the crux of the matter, and why I say this is where AGW is confused,
It’s nothing to do with AGW, it’s the fundamental basis of radiational heat transfer, read any book on the subject.
Reed – not all radiative energy is the same, different wavelengths have different properties, qualities, just as Real gases have different properties even though they are all gases. The ideal gas law CANNOT describe a real gas because the ideal gas is imaginary, it doesn’t exist, it’s a construct constrained by a description specific to itself alone; it describes no actual known gas. What one can imagine has to be from what is possible re real properties and what is actual environment.
Someone said above, sorry not time to check who, that our atmosphere is a closed system – ? Why say that? It’s obvious to anyone giving it even a modicum of thought that this isn’t true, but people say it because the laws AGW use are from a mishmash of out of context concepts such as ideal gases in a closed system, so what has Planck got to do with it? If it isn’t relevant to actual real life conditions it can’t be used, because it doesn’t work.
Somewhere up there I linked to the story why NASA junked Stefan-Boltzmann forty years ago for its real world calculations, because it wasn’t relevant to three dimensional reality; because it gave the wrong answers and they needed to be spot on. It seems deeply ironic that those anti this AGWScience are the ones called ‘flat earthers’…
Re what you think heat is, and Tim, it doesn’t matter. Whichever way you think of it, it cannot disobey the Law. If you come up with a clever sounding explanation which breaks it and then you fudge it so that you obtain an imaginary ‘net’ effect which does obey the Law, then you have still broken the Law. As I said. I really don’t think those arguing for this have fully taken on board the extraordinary thing they are claiming here.
Maybe it’s because of the overuse of ‘law’? Perhaps you (generic) think all laws can be played with at will. But somehow in this, laws specific to certain conditions only, from the ideal gas laws which are specific to imaginary gases only, to Planck and Bolzmann and the rest, are treated as if they are absolute laws applicable to all at every time and place while Absolute Laws, such as the 2nd, are dismissed as capable of being falsified, and moreover claimed falsified without any proof.
Elementary physics has been thrown out here. If you (generic) can’t see how ludicrous it is to think that a real gas which has weight and volume behaves in the atmosphere as if an ideal gas which has neither, and think that because the ideal imaginary gas spreads to fill the container according to its given properties means that a real gas CO2 behaves this way in the atmosphere, you’ll be easily convinced that CO2 can diffuse and spreads as this imaginary gas and take it as perfectly logical then that because it is well mixed by this imaginary diffusion it stays that way and can stay in the atmosphere for hundreds and even thousands of years accumulating. And then, you’re shocked to be told it is heavier than air and sinks to the ground displacing air unless work is done to make it otherwise. Or hearing this you come up with the equally absurd solution, so sure there is someway to prove this view from AGWScience, that when you’re told the answer is that the wind is constantly mixing it so it stays mixed you don’t even stop to consider what that would mean in the real world… And even then, most of the time you imagine wind to be a wooden paddle stirring molecules in empty space..
So, whatever your stars are doing or how they’re doing it, the colder is not heating the warmer at any time on any level of matter or energy.
So, either prove that the 2nd Law is broken by your (generic) radiation methodology, or keep imaginated scenarios where it is broken out of the argument. These are irrelevant. It is truly insulting to Real Science to keep presenting these as if they’re not. We can all imagine several impossible things before breakfast..
Context.
Solar energy is not heating the Earth and is not what we feel as Thermal Energy. Start there.
The rest should fall into place.
wayne says:
March 5, 2011 at 1:51 pm
I really appreciate that paper on O2-O2, N2-O2 interactions, etc. You just intuitively feel that is real and must be occurring and it’s great to get some real empirical backup on that thought. It’s going to take a long time for this whole puzzle to be solved. Phil likes to marginalize such small effects because they are not large like H2O’s and CO2’s emissivities by also there is hugely more O2 and N2 there, so the overall effect on the total energy flows is not what it seems when looking at CO2 in a cylinder in a lab. We all seem to get that.
Apparently you don’t, compared with the minuscule effect of the N2 and O2 there is not ‘hugely’ more of it. I do not ‘marginalize’ such small effects I tell it like it is and back it up with data. You on the other hand want to brag up N2 and O2 because you ‘intuitively feel’ that it must be significant to support your beliefs. Well science isn’t like that, your intuitive feeling doesn’t count, the facts are that N2 and O2 have negligible interaction with IR. Cut the handwaving and intuition show the data.
Myrrh says:
March 5, 2011 at 4:27 pm
Solar energy is not heating the Earth and is not what we feel as Thermal Energy. Start there.
OK, that’s nonsense.
The rest should fall into place
Yep, that’s nonsense too.
And Domenic – if you really think that you can get ‘background well-mixed CO2 levels’ sold as a ‘pristine site uncontaminated by local CO2 production’ from one of the most volcanic CO2 production regions on Earth then you’ve not thought it through..
Do you know how they work out this mythical “background well-mixed CO2” at Mauna Loa? Continuing in the tradition established by Keeling after less than 2 years of measurements on the world’s largest active volcano when he claimed he could measure man-made CO2 in all that , they decide what the numbers will be.
Seriously, that’s exactly what they do. Look up the discussions on WUWT and read through the method. They decide what is “volcanic” and what is “man-made background” cut-off point. Keeling neither proved that he was measuring ‘background CO2’ or that there even was such a thing, nor that he was able to differentiate ‘man-made’ from volcanic.
The AGW tradition was continued from him via his son and co-ordinated to include all stations kept in line to this base-line, and since has become even better organised.
Keeling didn’t believe in real world measurements, he had an agenda and created his ‘science facts’ to prove it.
And one last question to Ira re Near Infrared which is included in his Solar and which he says heats the Earth – why do you think it “is safe” in the following description?
http://www.licor.com/translational/NIR-optical-imaging-overview.jsp
Seriously, keep reading the NASA page I posted until this real world fact is thoroughly assimilated, Near IR is cool.
This is Real Science.
I am so fed up of this AGW junk science being taught to our children, they are incapable of understanding and will become incapable of creating real science knowledge as in this example.
AGW doesn’t have to burn books and destroy the educated to produce an ignorant generation it can mold to its masters’ will, they have (whoever they are) already succeeded in creating such an ignorant generation by producing AGWScience to do its work.
And knowingly or unknowingly, you are spreading it.
Phil, I have no “belief” but at least I now have the sites and papers given by others above that verifies nitrogen and oxygen’s role, however small for the emissivities at both sides of the IR spectrum are still hidden, to me at least. Thanks for not supplying them. And yes, there is massively more nitrogen and oxygen in our atmosphere. I noticed your objection to even that.
Pull that “out of context” again as you did to both Myrrh and myself and I will plead with Anthony to apply his rules of conduct.
@ur momisugly Myrrh
“Re what you think heat is, and Tim, it doesn’t matter. Whichever way you think of it, it cannot disobey the Law.”
Do you realize how this sounds? You can’t or won’t define “heat”. The classical statements of the second law are all about heat, yet “it doesn’t matter” what heat is?
If I think of heat as “temperature” then it must obey the 2nd law?
If I think of heat as “net flow of energy between two objects” then it must obey the 2nd law?
If I think of heat as “total thermal energy within an object” then it must obey the 2nd law?
PS Are you familiar with the modern, statistical mechanics definition of the 2nd law? It doesn’t even use the concept of “heat”, going instead straight to probabilities and entropy. So we could go that way and then the definition of heat wouldn’t matter — but then you better be prepared to discuss canonical ensembles and microstates.
Myrrh says:
March 5, 2011 at 4:27 pm
So, either prove that the 2nd Law is broken by your (generic) radiation methodology, or keep imaginated scenarios where it is broken out of the argument. These are irrelevant. It is truly insulting to Real Science to keep presenting these as if they’re not. We can all imagine several impossible things before breakfast.
First, I disagree that it is “insulting to Real Science” to present and discuss “imagined/imaginary” situations. Such “thought experiments” (e.g., what would the universe look like if you traveled on the crest of a light wave?) are one of the traits that made Einstein one of the leading 20th century scientists. His thought experiments may not have solved any “real-world” problems, but they provided a framework in which real-world problems could be and were solved.
Second, I don’t think I ever said the 2nd law is broken. In fact, I agree that it is not. What I did say was: In this sense, “net radiation” is equal to heat; and the (net radiation) will be in the direction of the star at the higher temperature to the star at the lower temperature.
I also agree that applying ideal laws, formulas, rules or whatever you want to call them to real-world scenarios is fraught with risk. In fact, I think this is one of the weaknesses of the proponents of AGW. The earth and its atmosphere is oversimplified in that their treatment of conduction/convection is weak if not nonexistent. However, ideal laws, formulas, and rules are a starting point. Since almost any real-world scenario is too complex to be represented by a set of formulas, your objection to “applying ideal laws to real-world situations” can be made to the formation/application of any manmade set of rules to any real-world situation. In determining/predicting the temperature of real-world objects in real-world situations, where do you suggest we start? If we (generic) followed your line of reasoning, isn’t it useless to even start? Any model/formulation/theory won’t exactly represent any real-world situation unless it includes the interactions of all matter/energy in the universe, which is impossible.
Just to make sure I don’t misrepresent you, I’d like to ask you three questions. Place a moon-like solid object (no or infinitesimal amounts of liquids and gases) with a small internal radioactive-decay source of thermal energy in space isolated from all other matter. First question: Will the temperature of the surface of this moon-like object be nonzero? Now place a second moon-like object lacking any form of internal energy generation in the vicinity of but not touching the original moon-like object. Second question: Will the original object’s surface temperature in the two-object case be the same or different than the original object’s surface temperature when in isolation? Third question: If different, will the temperature be higher or lower?
Finally, I agree with Tim Folkerts when he wrote:
March 5, 2011 at 3:01 pm
Myrrh,
I have one very simple request of you. Define precisely what you mean by “heat”. Until everyone agrees on the definition of this critical yet subtle idea, all the discussion in the world (any any side of the issues being discussed here) will be pointless.
However, even though I agree with Tim, (a) I won’t step up to his challenge to you and provide my definition of heat, and therefore (b) I am guilty of continuing a discussion that may in fact be “pointless.”