A guest post by Ken Coffman and Mikael Cronholm
In clicking around on the Internet, I found an outstanding paper called Thermodynamics of Furnace Tubes – Killing Popular Myths about Furnace Tube Temperature Measurement written by Mikael Cronholm. The paper was clever and wise…and made a lot of sense. Clearly Mikael knows a lot about infrared radiation and I’m a guy with questions. A match made in heaven?
We exchanged e-mails. I want to be clear about this…Mikael corrected some of my wrong ideas about IR. I’ll repeat that for the slow-witted. Some of my ideas about infrared radiation were wrong. I am considered a hard-headed, stubborn old guy and that’s completely true. However, I want to learn and I can be taught, but not by knuckleheads spewing nonsense and not by authoritarians who sit on thrones and toss out insults and edicts.
Ken Coffman (KLC) is the publisher of Stairway Press (www.stairwaypress.com) and the author of novels that include Hartz String Theory and Endangered Species.
Mikael Cronholm (MC) is an industry expert on infrared radiation, a licensed, level III Infrared Training Center Instructor and holds two Bachelor of Science degrees (Economics and Business Administration).
The following is a summary of our conversation.
KLC: Hello Mikael. I found your paper called Thermodynamics of Furnace Tubes and I found it very informative, practical and interesting. I hope you’ll bear with me while I ask a couple of dumb questions. I am an electrical engineer, so I have some knowledge about thermodynamics of conduction and convection, but not so much about IR radiation. In return for your time, I would be happy to make a donation to the charity of your choice.
If I take an inexpensive IR thermometer outside, point it at the sky and get a temperature reading of minus 25°C, what am I actually measuring? Is there anything valid about doing this?
MC: Just as a matter of curiosity, how did you find my paper? I checked your website and I guess this has to do with the Dragon, no? If you want to make a donation I would be happy to receive that book. If you can, my postal address is at the bottom. I don’t follow the debate more than casually, but I am a bit skeptical to all the research that is done on climate change…it seems that the models are continuously adjusted to fit the inputs, so that you get the wanted output…and they argue “so many scientists agree with this and that”…well, science is not a democracy…anyway…
About radiation, then. There is more to this than meets the eye. Literally!
Looking at the sky with an infrared radiometer you would read what is termed “apparent temperature” (if the instrument is set to emissivity 1 and the distance setting is zero, provided the instrument has any compensation). Your instrument is then receiving the same radiation as a blackbody would do if it had a temperature of -25°C, if that is what you measure. It is a quasi-temperature of sorts, because you don’t really measure on a particular object in any particular place, but a combination of radiation, where that from outer space is the lowest, close to absolute zero, and the immediate atmosphere closest to you is the warmest. (I have once measured -96°C on the sky at 0°C ground temperature.) What we have to realize though, is that temperature can never be directly measured. We measure the height of a liquid in a common thermometer, a voltage in a thermocouple, etc, and then it is calibrated using the zeroth law of thermodynamics and assuming equilibrium with the device and the reference.
KLC: Global warming (greenhouse gas) theory depends on atmospheric CO2 molecules absorbing IR radiation and “back radiating” this energy back toward the earth. If you look at the notorious Ternberth/Keihl energy balance schematic (as shown in Figure 1 of this paper: http://www.cgd.ucar.edu/cas/Trenberth/trenberth.papers/TFK_bams09.pdf ), you see the back radiation is determined to be very significant…more than 300W/m2. From your point of view as an IR expert, does this aspect of the global warming theory make any sense?
MC: The paper you sent me mentions Stefan-Boltzman’s law, but it does not talk about Planck’s law, which is necessary to understand what is happening spectrally. I suggest you read up on Planck and Stefan-Boltzman at Wikipedia or something. Wien’s law would be beneficial as well—they are all connected.
Planck’s law describes the distribution of radiated power from a blackbody over wavelength. You end up with a curve for each blackbody temperature. The sun is almost a blackbody, so it follows Planck quite well, and it has a peak at about 480nm, right in the middle of visual (Wien’s law determines that). The solar spectrum is slightly modified as it passes through the atmosphere, but still pretty close to Planckian. When the radiation hits the ground, the absorbed part heats it. The re-radiated power is going to have a different spectral distribution, with a peak around 10um (micrometer). Assuming blackbody radiation it would also follow Planck’s law.
S-B’s law is in principle the integral of Planck from zero to infinity wavelength. Instruments do not have equal response from zero to infinity, but they are calibrated against blackbodies, and whatever signal they output is considered to mean the temperature of the blackbody. And so on for a number of blackbodies until you have a calibration curve that can be fitted for conversion in the instrument.
That means that the instrument can only measure correctly on targets that are either blackbodies, or greybodies with a spectral distribution looking like a Planck curve, but at a known offset. That offset is emissivity, the epsilon in your S-B equation in that paper. It is defined as the ratio of the radiation from the greybody to that of the blackbody, both at the same temperature (and wave length, and angle…). Some targets will not be Planckian, but have a spectral distribution that is different. If you want to measure temperature of those, you need to measure the emissivity with the same instrument and at a temperature reasonably close to the one you will measure on the target later.
So, of course, the whole principle behind the greenhouse effect is that shorter wavelengths from the sun penetrates the atmosphere easily, whereas the re-radiated power—being at a longer wavelength—is reflected back at a higher degree. I have no dispute about that fact. It is reasonable. So I think the Figure 1 you refer to is correct in principle. My immediate question is raised regarding the numbers in there though. The remaining 0.9 W/m2 seems awfully close to what I would assume to be the inaccuracies in the numbers input to calculate it. You are balancing on a very thin knifes edge with such big numbers as inputs for reaching such a small one. An error of +/- 0.5% on each measurement would potentially throw it off quite a bit, in the worst case. But I don’t know what they use to measure this, only that all the instruments I use have much less accuracy than that. But with long integration times…well, maybe…but there may be an issue there.
KLC: I am interested in some rather expensive thermopile-based radiation detectors called pyrgeometers (an example is the KippZonen CGR 3 instrument http://www.kippzonen.com/?product/16132/CGR+3.aspx).
If a piece of equipment like this is pointed into the nighttime sky and reads something like 300W/m2 of downwelling IR radiation, what is it actually measuring? If I built a test rig from IR-emitting lightbulbs calibrated to emit 300W/m2 and placed this over the pyrgeometers, would I get the same reading?
MC: “What is it actually measuring?” Well, probably a voltage from those thermopiles…and that signal has to be calibrated to a bunch of blackbody reference sources to covert it either to temperature or blackbody equivalent radiation.
Your experiment will fail, though! If you want to do something like that, you have to look at a target emitting a blackbody equivalent spectrum, which is what the instrument should be calibrated to. IR light bulbs emitting 300W/m2 is simply impossible, because 300W/m2 corresponds to a very low temperature! Use S-B’s law and try it yourself. Like this: room temp, 20°C = 293K. The radiated power from that is 293K raised to the power of 4. Then multiply with sigma, the constant in S-B’s law, which is 5.67*10-8, and you get 419 W/m2 or something like that, it varies with how many decimals you use for absolute zero when you convert to Kelvin. For 300 W/m2 radiation I get -23.4°C at 300 W/m2 when I calculate it (yes, minus!). Pretty cool light bulb.
I don’t know what your point is with that experiment, but if it is to check their calibration you need a lot more sophisticated blackbody reference sources if you want to do it at that temperature. But you could do a test at room temperature though. Just build a spherical object with the inside painted with flat black paint, make a small hole in it, just big enough for your sensor, and measure the temperature inside that sphere with a thermocouple, on the surface. Keep it in a stable room temperature at a steady state as well as you can and convert the temperature to radiation using S-B’s law. You should get the same as the instrument. Any difference will be attributable to inaccuracy in the thermocouple you use and/or the tested instrument. Remember that raising to the power of 4 exaggerates errors in the input a lot!
I hope I have been able to clarify things a little bit, or at least caused some creative confusion. When I teach thermography I find that the more you learn the more confused you get, but on a higher level. Every question answered raises a few more, which grows the confusion exponentially. It makes the subject interesting, though.
Let me know if you need any more help with your project!
KLC: I found your paper because one of the FLIR divisions is local and I was searching their site for reference information about IR radiation. I know what a 100W IR lamp feels like because I have one in my bathroom. If someone tells me there is 300W/m2 of IR power coming from space, and I hold out my hand…I expect to feel it. What am I missing?
MC: Yeah, you put your hand in front of a 100W bulb, but how big is your hand…not a square meter, I’m sure. It is per area unit, that is one thing you are missing. The 100W of the bulb is the electrical power consumption, not the emitted power of the visual light from it. That’s why florescent energy-saving lamps as opposed to incandescent bulbs give much more visual light per electrical Watt, because they limit the radiation to the visual part of the spectrum and lose less in the IR, which we cannot see anyway. The body absorbs both IR and visual, but a little less visual.
And, here is the other clue. Your light bulb radiation in your bathroom is added to that of the room itself, which is 419 W/m2, if the room is 20°C. Your 300 W/m2 from space is only that. You will feel those 300 W/m2, sure. It will feel like -25°C radiating towards your hand. But you don’t feel that cold because your hand is in warmer air, receiving heat (or losing less) from there too.
Actually, we cannot really feel temperature—that is a misconception. Our bodies feel heat flow rate and adjust the temperature accordingly. It is only the hypothalamus inside the brain that really has constant temperature. If you are standing nude in your bathroom, your body will radiate approximately 648 W/m2 and the room 419 W/m2, so you lose 229 W/m2. That is what you feel as being cooled by the room, from radiation only. Conduction and convection should be added of course. The earth works the same way—lose some, gain some. It is that balance that is being argued in the whole global warming debate.
KLC: I still feel like I’m missing something. IR heat lamps are pretty efficient, maybe 90%? Let’s pick a distance of 1 meter and I want to create a one-square meter flooded with an additional 300W/m2. It must be additional irradiation, doesn’t it? That’s going to take a good bunch of lamps and I would feel this heat. However, I go outside and hold out my hand. It’s cold. There’s no equivalent of 300W/m2 heater in addition to whatever has heated the ambient air.
Perhaps I’m puzzled by something that is more like a flux…something that just is as a side-effect of a temperature difference and not really something that is capable of doing any work or as a vehicle for transporting heat energy.
It’s a canard of climate science that increasing atmospheric CO2 from 390PPM to 780PPM will raise the earth’s surface temperature by about 1°C (expanded to 3°C by positive feedbacks). From my way of thinking, the only thing CO2 can do is increase coupling to space…it certainly can’t store or trap energy or increase the earth’s peak or 24-hour average temperature.
Any comments are welcome.
MC: Efficiency of a lamp depends on what you want, if heat is what want then they are 100% efficient, because all electrical energy will be converted to heat, the visible light as well, when it is absorbed by the surrounding room. If visible light is required, a light bulb loses a lot of heat compared to an energy saving lamp. Energy cannot be created or destroyed—first law of thermodynamics.
When you say W/m2 you ARE in fact talking about a flux (heat flow is what will be in W). If you have two objects radiating towards each other, the heat flow direction will be from the hotter one, radiating (emitting) more and absorbing less, to the cooler one, which radiates less and absorbs more (second law of thermodynamics). The amount of radiation emitted from each of them depends on two things ONLY, the temperature of the object and its emissivity. So radiation is not a side effect to temperature, it is THE EFFECT. Anything with a temperature will radiate according to it, and emissivity. (If something is hotter than 500°C we get incandescence, emission of visible light.) Assuming an emissivity of unity, which is what everyone seems to do in this debate, the radiation (flux. integrated from zero to infinity) will be equal to what can be calculated by Stefan-Boltzmann’s law, which is temperature in Kelvin, raised to the fourth power, multiplied by that constant sigma. It’s that simple!
With regard to your thought experiment, it is always easier to calculate what an object emits than what it absorbs, because emission will be spreading diffusely from an object, so exactly where it ends up is difficult to predict. I am not sure where you are aiming with that idea, but it does not seem to be an easy experiment to do in real life, at least not with limited resources.
CO2 is a pretty powerful absorber of radiated energy, that fact is well known. Water vapor is an even stronger absorber. In the climate debate it is also considered a reflector, which probably also true, because that is universal. Everything absorbs and reflects to a degree. So I guess that the feedback you mention has to do with the fact that increasing temperature increases the amount of water vapor, which increases absorption, and so on. But my knowledge is pretty much limited to what happens down here on earth, because that is what matters when we measure temperature using infrared radiation. However, it is important to remember, again, that we talk about different spectral bands, the influx is concentrated around a peak in the visual band and the outgoing flux is around 10 micrometer in the infrared band, and the absorption may not be the same.
With so many scientists arguing about the effects of CO2 I am not the one to think I have the answers. I really don’t know what the truth is. And the problem that all these scientists have is that they will never be able to test if their theories are correct, because the time spans are too long. For a theory to be scientifically proven, it has to be stipulated and tested, and the test must be repeatable and give the same results in successive tests for the theory to be proven.
If not, it is not science, it is guessing.
More like a horoscope…
@ur momisugly Jim. Thanks! I have previously only had a casual interest in the issue of global warming (or not?) and I still don’t know what the final answer may be, but I have gained some very valuable insights from many of the comments made here.
On the definition of heat, we probably don’t even need to agree to disagree, since we are both victims of the semantic confusion that exists. I no longer make the mistake of arguing one way or the other, and the choice of principle I have made for teaching is for purely didactic reasons. The physics remain the same anyway!
Hi Mikael
It’s been very enjoyable to join you in these discussions. I really hadn’t engaged much in the AGW debate until lately. There really hadn’t been any good venue to be able to do so until Anthony got WUWT up and running.
It’s been about seven years since I’ve even engaged in any ‘infrared’ discussions in any meaningful way with interested parties. So, it has been a good exercise to share in that. And doing so, has triggered some insights that I hadn’t seen before.
I don’t mind the ‘Will’s of the world. The science of infrared, and the thinking involved, is quite arcane and alien to most people. By its nature, it forces one to look at ‘wholes’ rather than ‘pieces’ as is common in the thinking of most people.
I have noted your email, thank you. I don’t think I will be getting to Thailand for at least a few years, but I do appreciate it.
@ur momisugly Mikael,
It looks like the sign-off prayer here, so I’ll just say thanks, too, and commend the whole AGW thing to you as a fascinating topic from physics through economics to social and individual psychology.
It’s fun to argue.
http://www.coe.ou.edu/sserg/web/Results/Spectrum/o2.pdf and http://www.coe.ou.edu/sserg/web/Results/Spectrum/n2.pdf show the IR spectra of O2 and N2, respectively. Unfortunately, there are no spectra for H2O and CO2 for comparison. The following table compares the peak absorption coefficients per molecule for several molecules.
CO2 1 E-19
H2O 1 E-18
O2 1 E-28
N2 1 E-28
The bigger the value, the more energy is absorbed. Granted, these numbers must be multiplied by the total number of molecules in the column to get the actual absorption. However, the relative concentrations can be used to make simple comparisons. Since water vapor is about 1% of the lower atmosphere (10,000 ppm) on a dry day and because it absorbs at many more frequencies than any of the other 3, you can see why it is the main greenhouse gas in the troposphere. Basically, after adjusting for the relative concentrations, it is 8 orders of magnitude stronger than O2 or N2. At the bottom of the tropopause, water vapor is still about 70 ppm and it is still the strongest greenhouse gas.
At any rate, these numbers explain why so many people agree that O2 and N2 are IR transparent.
In addition, for a given molecule, radiation is absorbed and emitted at exactly the same frequencies (same spectrum). It is not correct to assume that O2 absorbs with one spectrum and emits with a blackbody spectrum. The only exceptions I know to this are fluorescence and phosphorescence.
For George E. Smith:
The radiation spectra for a gas at a given temperature is the blackbody spectra for that temperature times the spectra coefficients from the HITRAN database (adjusted for temperature and pressure) times the number of molecules in the path. Thus the emission spectra is always less than or equal to the blackbody spectra.
Also, you seem to think that desert air contains no water. Actually, it contains a lot (perhaps 1,000 ppm or so), just not enough condense and form dew and/or fog in the mornings.
Mikael Cronholm says: at 5:55 pm on Feb 17th
“Will is obviously in the business of peddling misinformation. Look at the silly stuff with water bottles that he has on his website. Click his name. How many scientific errors can you find in that experiment? But to a layman it might seem like it would be true, although it does not prove anything that it claims to prove.”
Mikael, thank you for pointing out the experiment shown by Will is full of scientific errors.
As a stupid ignorant layman I could not see so many.
Perhaps he was using the wrong kind of CO2; we all know the manmade stuff is much more dangerous…
Perhaps you could show us the version of the experiment that YOU run without the errors.
What are the errors in Will’s experiment?
NoIdea
Mikael,
“@ur momisugly Will. And no further answers to you! I find it a bit insulting that you ask me to explain things to you that you already claim to know. But still don’t seem to understand at all…”
I understand very well.
I understand that on the one hand you have claimed that glass is opaque to IR, as in that it acts as a barrier to IR. Then on the other hand you have claimed that is a near perfect black-body absorber and emitter at 0.97 above 8 µm.
I understand that these two claims could not possibly be more contradictory and unscientific.
I understand that anyone who ignores such contradiction has no interested in the truth.
I also understand the definition of slander, so in the interests of fair play, I think you should know that I archive all threads on which I post for future use.
Finally, I want to thank you Mikael, you have been very helpful.
H/T NoIdea
@ur momisugly NoIdea. The first and most important one has to with the transmissivity of the bottles. They will spectrally modify the radiation that shines on them, which has the wrong spectrum to start with. Exactly how they do that requires a spectral curve of the material, for the thickness they have. I have a feeling, from looking at such bottles with IR cameras, that they will be opaque or just slightly transparent in the 2-14um band. In any case, they will change the radiation enough to make the test invalid. I have been trying to explain those things in vain for a while, so there is plenty above to read about it.
Someone made a comment somewhere in this thread asking me if I was going to launch a rocket from my garage soon. I have worked with missiles and a Mach 2.5 windtunnel (free blowing, of course), to look at aerodynamics of stabilizer fins and such, but I have no such plans for myself. The people who made that experiment seem to be up for anything though! That which well equipped scientists have a hard time with in labs, they can do at home! What will come next? 🙂
@ur momisugly Robert Clemenzi. As a matter of fact, even desert air will condense, but not on the ground, which is perhaps what you mean. The ground has too high heat capacity to cool down enough by radiating heat to the sky. But on objects with less heatcapacity, water will condense from the air. That is how a cactus can survive. Water condenses on the needles, or barbs, or what you call them, because they are dry in themselves and away from the cactus that remains warm due to the heat it has accumulated. The condensed water on the needles will run down to the roots and be absorbed there. Cactii have short roots and with very sporadic rainfall they will have no other way to reach water except that the cactus makes the water itself.
In military special forces they use old desert techniques to create water from the air by placing a piece of cloth or something on sticks with a small rock in the middle to make an upside down tentlike device which will cool down towards the sky, enough to go below the dewpoint and get condensation.
It can be REALLY cold in the desert at night too. Because of the relative lack of greenhouse effect, due to low levels of water vapor. Which kind of ties this together with the topic 🙂
Robert Clemenzi says:
February 18, 2011 at 1:17 am
http://www.coe.ou.edu/sserg/web/Results/Spectrum/o2.pdf and http://www.coe.ou.edu/sserg/web/Results/Spectrum/n2.pdf show the IR spectra of O2 and N2, respectively. Unfortunately, there are no spectra for H2O and CO2 for comparison. The following table compares the peak absorption coefficients per molecule for several molecules.
CO2 1 E-19
H2O 1 E-18
O2 1 E-28
N2 1 E-28
————————–
Again, this is based on the assumption that N2 and O2 are Zero (on the scale of 0 to 1 for blackbodies).
We know N2 and O2 warm up to reflect the air temperature at whatever location or height they are in the atmosphere. So no emission or absorption other than these two very weak specific spectra?
——————————-
From Raymond Pierrehumbert’s recent article on planetary atmospheres and the greenhouse effect (Pierrehumbert is the newest star expert on atmospheric physics on the pro-AGW side having also written a long textbook on the matter which will likely become a key source at universities etc.)
” An IR photon absorbed by a molecule knocks the molecule into a higher-energy quantum state. Those states have very long lifetimes, characterized by the spectroscopically measurable Einstein A coefficient. For example, for the CO2 transitions that are most significant in the thermal IR, the lifetimes tend to range from a few milliseconds to a few tenths of a second. In contrast, the typical time between collisions for, say, a nitrogen-dominated atmosphere at a pressure of 104 Pa and temperature of 250 K is well under 10−7 s. Therefore, the energy of the photon will almost always be assimilated by collisions into the general energy pool of the matter and establish a new Maxwell–Boltzmann distribution at a slightly higher temperature. That is how radiation heats matter in the LTE limit.”
He then goes on to explain the formulae etc. and then writes …
“We can determine that temperatures of the atmosphere and ground range at least from 220K to 285K. But absent additional information, we cannot tell that the high end of that range actually comes from the ground.”
—————-
The 220 K is where the CO2 spectral band dominates and 285 K is the atmospheric windows where N2 and O2 blackbody radiation dominate. But they cannot tell what the origination point is for the 285K blackbody radiation from N2 and O2. It might be directly from the ground or it could be 20 kms high where the density of air falls to a level which starts to allow a 50:50 chance of a photon being emitted directly to space.
I choose to believe the “lapse rate” tells us exactly what is happening to the energy levels in the atmosphere and where the radiation is going and which molecules are excited etc.
It is different than the way Pierrehumbert explains it and it does not completely ignore blackbody radiation which seems to be how the global warming theory got started – by focussing on the specific absorption bands only and ignoring collision rates and blackbody radiation in the atmosphere.
barn E. rubble says:
February 17, 2011 at 8:55 am
I am. And you’d be one of them. Having found most what’s been posted here to be tuff skate; it has been most informative.
I’m pleased it was of use to you, but teacher I’m not. I’d be wary of any setting themselves up as ‘teachers’ of ‘climate change’, for one thing the subject takes in sooo many fields of knowledge that it would be genius who could put all that together, even if any had the time, valiant attempts have been made. From what I’ve gathered from individual stories here, it’s an aspect of it already of interest that draws people in to explore AGW further, often started by something it claims which jars with one’s own knowledge, with something one has learned and still seems logical. I was drawn in when I found that people were arguing about it, curiosity. Someone in that discussion gave me some basics and knowing something about graphs the first thing I questioned was the claim that the the temperature rise since the Industrial Revolution was anything unusual. It was obvious to me knowing we had gone through a cold period around that time, though not knowing it was called the Little Ice Age, that using this cold period as a starting point on a graph was bound to show warming. The AGW’s then pointed me to info on the Hockey Stick, and I found it was well on its way to being debunked for deliberately eliminating the LIA and Medieval Warm Period (MWP), though still trying to get a lot of the data which was being withheld and which in science claims should be freely available for checking by others. That really jarred, but worse, was the well educated scientist who was arguing for the Hockey Stick version of events didn’t see anything wrong in this. And it continued to deteriorate, until every counter argument I found which I thought would be a launch pad for discussion, I was still trying to get my head around some of the arguments and wanted clarification, he returned with curt dismissal, refusing even to read them. It was quite some time before I found that some discussions about AGW on other sites had the same attitude problem and posts that were too uncomforable for AGW supporters would be censored, or just deleted, and people banned from posting. All that to say I think most ‘skeptics’ are just people who’ve come to a point were they can no longer take AGW seriously, and from there it’s just further exploration into the absurdities of it; so what you’ll find is not teachers, but fellow travellers discussing it, arguing with all comers and telling tales of their experiences around camp fires.
Do I understand correctly (from what I read from Myrrh) that CO2 levels, however increased, does not in fact mix or average out at increased levels globally but would accumulate locally, i.e: where it is being produced and cycle about unless moved by other forces and dissipate sooner rather than later?
That’s how I understand it. There isn’t one huge wind mixing up our atmosphere as if it’s a wooden spoon stirring porridge, and it’s not ’empty space’ in which Ideal gases travel at great speed with no constraints apart from bouncing off each other. Weather is local and the properties of CO2 relative to air will be in the air it’s relating to locally. This concept from AGW of “background well-mixed” isn’t feasible.
Mauna Loa measurements a bad joke, firstly because they claim it is a “pristine site” for measurement, one in which their measurements of this supposedly background level is uncontaminated by local output. It’s on the world’s biggest active volcano, in an area of immense volcanic activity in a warm sea with its own pattern of winds stirring all this up – it is impossible for them to measure ‘background’ CO2 in all this even if such as thing existed. And if you look at their method of measuring you’ll find they simply decide what it should be and adjust their findings accordingly, in AGW speak which is garble sounding ‘scientific’. Keeling, who began measurements there, had an agenda. He couldn’t wait to promote it, in less than two years of measurements he declared he had found conclusively that CO2 background level was rising from man-made sources. He had an awful lot of CO2 to play with.. His famous Keeling Curve showing steady increase of CO2 over the decades since bears no relationship to any temp changes in those decades, which is why AGWScience continually re-adjusts past temperatures to better hide the decades of cooling.
Further, the GH effect of CO2 as per warming the surface temp by re-emitting IR/heat energy towards the surface is negligible?
Some here have looked into this in great detail in the many facets this is presented by AGW, and so conclude.
Is there no peer reviewed papers (for what that’s arguably worth) on the natural separation of in our atmosphere that Myrrh mentions?)
I put it together for myself because puzzled that AGWScience made these claims for CO2, and I couldn’t find any concentrated discussion about it at the time. There’s a lot of scattered information, and that aspect is becoming more discussed, and there’s now a new discussion on the front page here about CO2 which I haven’t had time to read yet. My info came mostly from old fashioned science about CO2, and gases generally re weight and so on, because well known in all sorts of practical common areas. Mining is a good example (and how I first learned of it in school, around age 10) and I was interested in discovering how AGW could make such claims for CO2 that its properties weren’t capable of effecting. That’s when I found they were using laws out of context, and this is a pattern repeated in other aspects of the claims. They often miss stuff out – the classic is not accounting for water in cooling the atmosphere, by taking heat away in water vapour, so they have it only as ‘a greenhouse warming gas’, and then not in its own right, because they say this is too complicated to model and doesn’t stay in the atmosphere long enough to be a problem (remember they’re claiming absurd accumulation times for CO2 for their blanket), but only by some idea that CO2 amplifies warming effect of water, whatever it is. Again, others have explored this in more depth.
Back to IR:
A small aside here from examples used earlier on. There is not such thing as an IR sauna. Full stop. Perhaps just a misnomer but the literal translation of ‘sauna’ is steam bath. You can no more have a ‘dry’ sauna than you can have a ‘dry’ shower or bubble bath. Call it a warm room or seat closet but a sauna it is not (pronounced: sow-na) it irritates your Fin friends, believe me.
I’m sorry but they’re stuck with it. Like Cheddar cheese, all kinds of cheeses masquerading as the real thing.. But, in a sauna one can choose whether or not to dump water onto the rocks, making it a dry sauna. Do the Fins never do this? If they do, do they still call it a sauna?
Always sweating the small stuff
That creates steam whatever the method of heating the hot room..
I would like to publicly thank Mikael and Domenic and George and Oliver and Robert and Barn E., and yes, even Will, and all the other contributors for a stimulating and interesting conversation. In any public arena, there will be a few folks who contribute more to ‘noise’ than ‘signal’, but it’s been mostly tolerable in this thread. Also, I would like to thank Anthony for giving us this forum and hosting a great conversation.
Can I add one more dumb question? Let’s take an N2 molecule as an example. I think we all agree…if it has a temperature, it will radiate and for N2 the wavelength is real short. Nonetheless, isn’t this emitted energy highly-significant from an energy balance POV? It’s a short wavelength, but isn’t there a lot of it? I feel like there is a missing piece in my thinking.
Thanks!
To Robert Clemenzi
Unfortunately, those curves you link to cannot be trusted. They are only partial data.
Notice the preponderence of peaks up to 6 microns or so, then the lack of any peaks for wavelengths longer than that. In the O2 graph, for example, they skip all the way to nearly 1000 microns. They do that in the graphs because real data has never been taken in the 6 to 1000 micron range. They can only put in what they have tested or guessed (calculated).
That is the problem.
If you have followed my posts here, I have explained why. It is because those physical measurements are difficult to make. But in order to understand the true effects of O2 and N2 in the atmosphere and their contribution to the greenhouse effect, those physical absorption measurements must be made. Real data must be taken in those long wavelengths, not guessed at or calculated.
To Ken Coffman, and others still here
Because of this topic, I’ve started to look very closely at theAntarctic Vostock and Amendsun-Scott data. It’s the most pristine data out there.
You want to know what is really strange…that the data I’ve seen so far, from a radiational physics point of view, is showing that the ‘greenhouse effect’ of all the gases in the atmosphere is actually DECREASING! That surprised me.
Despite all the stuff we supposedly are putting into the atmosphere. Now that is indeed a shocker!
But then “Nature” has always been much different than many ‘think’ it is, always confounding man….
I am going to look into it more thoroughly.
Forgot to add…
In addition, it is water vapor, H2O, that has been saving our butts.
Ken and Mikael,
I have repeatedly given Mikael the opportunity clear up the ambiguity concerning the statement that glass is opaque to IR, by repeatedly adding the following caveat “as in that it acts as a barrier to IR.”
Yet he has consistently failed to clarify that this is a misconception of the word opaque.
The use of the word opaque and the phase “opaque to IR” in this context, is the source of a very serious misrepresentation of what occurs inside a greenhouse. It implies, as is perfectly obvious, that glass somehow blocks the passage of IR. Yet as has been demonstrated by Mikael’s link, glass certainly does not block IR because above 4 µm it is almost a pure black-body absorber and emitter. This means that IR is absorbed and emitted by the glass at light speed. As the interior of the greenhouse is always going to be warmer than the exterior, it naturally follows that the IR energy will pass through the glass to the exterior with the same ease as if it were “transmitted” and in that case the use of the phrase “opaque to IR” is pure semantics with the intention to deceive. Sometimes referred to as sophistry.
Not only has Mikael allowed this misconception of the use of the term “opaque to IR” to imply that glass presents a barrier to the passage of IR (the foundation of the “greenhouse effect hypothesis”) but in the example I have given regarding the IR sensor on my outdoor security light, which is empirical proof that glass does not block IR, he has failed acknowledge that this is the case and has allowed Domenic’s false claim that this test is invalid, to stand unchallenged.
This is a deliberate fraud, directly and by proxy.
As you Ken are the thread initiator and Mikael being the stated IR expert that you have called in to discuss the topic of IR, this makes you both equally responsible for public deception.
I notice that whoever is moderating this thread has blocked my last post and so I expect this post to disappear into the same memory hole. No matter, as I intend to circulate it widely as an open email to bring to as many peoples attention as possible, the deception to which you are both engaged.
You can however avoid such action by apologising for the misconception and acknowledging your mistake in explicitly implying that glass can block the passage of IR.
Regards
Will
Mikael – You sent me off to look at Boltzmann and Planck. Boltzmann I noted in an earlier post (February 16, 2011 at 2:09 pm), has been falsified by Feet2theFire. See his post above, (February 14, 2011 @ur momisugly 2:12 am).
In my post I linked to a site on measuring IR which had these two and two more laws under the heading: Theoretical Basis For IR Temperature Measurement, and asked if anyone could falsify the others.
I think I have for Planck’s Law: http://csep10.phys.utk.edu/astr162/lect/light/radiation.html
“The Planck Law gives a distribution that peaks at a certain wavelength, the peak shifts to shorter wavelengths for higher temperatures, and the area under the curve grows rapidly with increasing temperature.”
If I’ve understood that correctly, if it’s saying that the higher the temperature the more Visible light then it’s been falsified already, see here:
http://m.plantengineering.com/index.php?id=2831&tx_ttnews%5Btt_news%5D=33209&cHash=db4db9479b
Which says: “A sufficiently hot object will emit light or visible radiation, a phenomenon called incandescence. A light bulb filament, smoldering ember, and a billet of red-hot steel are examples of this phenomenon. The hotter the object, the brighter and whiter its color. It is possible to estimate the temperature of an object this way. Experienced steelworkers do this regularly.
Not as widely recognized is the fact that incandescent objects emit a tremendous amount of invisible infrared radiation. For example, the radiance of a steel billet at 1500F is 100,000 times greater in the infrared spectrum than in the visible spectrum.”
So, Planck’s Law is broken. A hot object gives out more long wavelengths than short, he got his peak wrong.
Both falsified.
So, what is it you want me to understand by these Laws?
Two more to go. (They might already have been shown falsified in this discussion, but I’ve failed to appreciate it.)
P.S. Which was what I was saying. All that it showed was that higher temperatures create the brighter colours of the shorter wavelengths, not that the shorter wavelength colours are hotter than the longer wave.
This has been quite enlightening and entertaining. Thank you, to all those who have offered their expertise, knowledge and opinion. I appreciate the patience shown to those of us PhD challenged. I’m hoping all those contributing on this thread haven’t signed off yet because I was looking for a brief summary re: IR and the AGW theory, that I can take away from all of this.
Two points from the thread (and unfortunately I didn’t copy contributor names).
1) CO2 negligible to global warming because:
“That leaves at MOST, 10-15% of the entire earth LWIR Radiant energy emissions subject to CO2 absorption.”
IE: CO2 only absorbs (and re-emits in 3D, Earth, atmosphere and space) a fraction of IR/heat energy that is being referred to as ‘back radiation’, the main issue driving AGW.
2) CO2 significant in global warming because:
“The simplest and quite accurate way to conceptualize this is that CO2 is an insulator . . .”
IE: CO2 absorbs (and re-emits back to Earth) a significant amount of IR/heat energy that is being referred to as ‘back radiation’, the main issue driving AGW
Have I got the main issues here?
Thank you for your time and trouble.
-barn
RE: IR with respect to O isotopes
Perhaps someone here can shed some light or even a thot on the following. Somewhere on this thread referred to some charts with Oxygen isotopes and corresponding IR wavelengths. I have been reading with some interest of the work coming out of the Univ. of Saskatchewan Isotope Lab where they’ve been using O isotopes for temp reconstructions. The colder the temp the more heavier O (18?) was found.
The question is: How does the IR/heat energy cause more (or less) of one isotope than another. IE: Does temperature change the isotopes?
Thank you for any insights.
-Barn
@William Hickman:
Oops: Climategate U-turn as scientist at centre of row admits: There has been no global warming since 1995
http://www.dailymail.co.uk/news/article-1250872/Climategate-U-turn-Astonishment-scientist-centre-global-warming-email-row-admits-data-organised.html#ixzz1EKbIpSQb
Why has this non-issue not simply dried up and died? Why isn’t this article known to every English-speaking man, woman, and child on the planet?
Still disgusted…
Myrrh says:
February 18, 2011 at 7:46 am
Not as widely recognized is the fact that incandescent objects emit a tremendous amount of invisible infrared radiation. For example, the radiance of a steel billet at 1500F is 100,000 times greater in the infrared spectrum than in the visible spectrum.”
So, Planck’s Law is broken. A hot object gives out more long wavelengths than short, he got his peak wrong.
Both falsified.
So, what is it you want me to understand by these Laws?
Some understanding would help, your claim of falsification is nonsense.
According to Planck a blackbody at 1500ºF (~1100K) has a peak emission at ~2.7μm significantly in the NIR, whereas at 3000K it’s 1μm so much more visible light, at 6000K it’s 0.5μm in the visible spectrum. Hint, 1100K isn’t ‘hot’.
@ur momisugly Myrrh. My goodness! You are just too much! It is actually quite amusing to see you fooling yourself by turning things inside out. I am just waiting for you to see an airplane flying past and come running in here saying that Newton got it all wrong, gravity is falsified!
According to those laws you just “falsified”, your 1500F (815C in real units) steel slab will radiate its peak emission at about 2.7 um (simplifying it as a blackbody, it’s close enough). So there is no contradiction at all. Sure, 2.7 um is in the infrared, not visual, just like your source says, and just like Planck and Wien will tell you. The people at Plant Engineering who came up with those numbers will have used the same laws (Stefan-Boltzman, which is the zero-to-infinity integral of Planck) to calculate the numbers that you claim are falsified by the very same numbers. Really funny my friend!
It is the sun that peaks in visual, at 480 nm or thereabouts. Hotter than the sun – even shoreter peak emission.
And this;
““The Planck Law gives a distribution that peaks at a certain wavelength, the peak shifts to shorter wavelengths for higher temperatures, and the area under the curve grows rapidly with increasing temperature.”
If I’ve understood that correctly, if it’s saying that the higher the temperature the more Visible light then it’s been falsified already, see here:”
Weeeellll Myrrh, the higher the temperture, the more of ALL wavelenghts will be emitted. It is just the peak that shifts to shorter wavelengths.
What will you amuse me with next? 🙂
To Mikael Cronholm
It is my understanding that the plastic in the desert condenses water on the bottom of the plastic, not the top. From Collect Water in a Solar Still
“Moisture from the soil then evaporates, rises and condenses on the underside of the plastic barrier above.”
Notice, this device increases the amount of water vapor under the plastic and does not collect water from the atmosphere.
I agree with you that a small amount of condensation occurs in the desert. However, in more moist climates, it is the morning dew and fog that release latent heat and keeps the surface warm .. which explains why the dry deserts are colder. At any rate, my main point was that even “dry” air still has a lot of water vapor and George E. Smith was suggesting that “dry” means “none”.
For Ken Coffman
For the emission at a given temperature, the gas spectra has to be multiplied by the blackbody spectra for each frequency. If the gas has a strong emission line at a short wavelength, but a blackbody would not emit at that wavelength, then neither will the gas. This is part of the reason why O2 and N2 don’t play a part in spectral absorption and emission at 15C, it simply is not hot enough. In fact, both O2 and N2 have absorption frequencies in the IR band, but their coefficients of emission are more than 8 powers of ten lower than the “active” gases. Those gaps in the spectra are not because no one has tried to measure the absorption there. Instead, it is because the absorption is so weak that our instruments can not detect anything to measure. In addition, “normal” diatomic molecules do not have any peaks in the range we are discussing. The peaks that are there are because the two atoms in the molecule are different isotopes of the same element. For example, O16-O18 will have a spectra in that region, but O16-O16 will not. This spectra in the plots is low because the coefficients were adjusted to account for the natural abundance of O18, which is very small.
@ur momisugly Will. You are also amusing me more and more, so I give you this:
You: “The use of the word opaque and the phase “opaque to IR” in this context, is the source of a very serious misrepresentation of what occurs inside a greenhouse. It implies, as is perfectly obvious, that glass somehow blocks the passage of IR. Yet as has been demonstrated by Mikael’s link, glass certainly does not block IR because above 4 µm it is almost a pure black-body absorber and emitter.”
I think you have a problem understanding what a blackbody is, that is where the confusion is. It absorbs 100% of all incoming radiation at all wavelengths. Then it emits 100% according to S-B’s law (gives the flux), and Planck (gives the wavelength distribution), at whatever temperature it has. Yes, an almost pure blackbody absorber and emitter will ABSORB, and hence cannot transmit any infrared radiation over 4um, approx. (It will reflect the rest. You did say you knew Kirchhoff, no?) For heat to pass to the other side of the glass, it has to do so by conduction. Then it will radiate on the other side again, according to its temperature and following those pesky laws… but by radiation the energy WILL NOT pass through. End of story.
And I will not apologise for knowing and understanding elementary radiation physics 🙂