Guest post by Bob Fernley-Jones by Bob Fernley-Jones AKA Bob_FJ
CAUTION: This is written in Anglo-Oz English.
Here is the diagram as extracted from their 2009 paper, it being an update of that in the IPCC report of 2007 (& also 2001):
The unusual aspect of this diagram is that instead of directly showing radiative Heat Transfer from the surface, it gives their depiction of the greenhouse effect in terms of radiation flux or Electro-Magnetic Radiation, (AKA; EMR and a number of other descriptions of conflict between applied scientists and physicists). EMR is a form of energy that is sometimes confused with HEAT. It will be explained later, that the 396 W/m^2 surface radiation depicted above has very different behaviour to HEAT. Furthermore, temperature change in matter can only take place when there is a HEAT transfer, regardless of how much EMR is whizzing around in the atmosphere.
A more popular schematic from various divisions around NASA and Wikipedia etc, is next, and it avoids the issue above:
- Figure 2 NASA
Returning to the Trenberth et al paper, (link is in line 1 above), they give that the 396 W/m2 of EMR emitted from the surface in Fig.1 is calculated primarily by using the Stefan–Boltzmann law, and global year average conditions. Putting aside a few lesser but rather significant issues therein, it is useful to know that:
1) The Stefan-Boltzmann law (S-B) describes the total emission from a flat surface that is equally radiated in all directions, (is isotropic/hemispherical). Stefan found this via experimental measurement, and later his student Boltzmann derived it mathematically.
2) The validity of equally distributed hemispherical EMR is demonstrated quite well by observing the Sun. (with eye protection). It appears to be a flat disc of uniform brightness, but of course it is a sphere, and at its outer edge, the radiation towards Earth is tangential from its apparent surface, not vertical. It is not a perfect demonstration because of a phenomenon called limb darkening, due to the Sun not having a definable surface, but actually plasma with opacity effects. However, it is generally not apparent to the eye and the normally observed (shielded) eyeball observation is arguably adequate for purpose here.
3) Whilst reportedly the original Stefan lab test was for a small flat body radiating into a hemisphere, its conclusions can be extended to larger areas by simple addition of many small flat bodies of collectively flat configuration, because of the ability of EMR waves to pass through each other. This can be demonstrated by car driving at night, when approaching headlights do not change in brightness as a consequence of your own headlights opposing them. (not to be confused with any dazzling effects and fringe illumination)
4) My sketch below demonstrates how radiation is at its greatest concentration in the lateral directions. It applies to both the initial S-B hemispherical surface radiation and to subsequent spherical radiation from the atmosphere itself.
5) Expanding on the text in Figure 3: Air temperature decreases with altitude, (with lapse rate), but if we take any thin layer of air over a small region, and time interval, and with little turbulence, the temperature in the layer can be treated as constant. Yet, the most concentrated radiation within the layer is horizontal in all directions, but with a net heat transfer of zero. Where the radiation is not perfectly horizontal, adjacent layers will provide interception of it.
A more concise way of looking at it is with vectors, which put simply is a mathematical method for analysing parameters that 
possess directional information. Figure 4, takes a random ray of EMR (C) at a modestly shallow angle, and analyses its vertical and horizontal vector components. The length of each vector is proportional to the power of the ray, in that direction, such that A + B = C. Of course this figure is only in 2D, and there are countless multi-directional rays in 3D, with the majority approaching the horizontal, through 360 planar degrees, where the vertical components also approach zero.
6) Trenberth’s figure 1 gives that 65% of the HEAT loss from the surface is via thermals and evapo-transpiration. What is not elaborated is that as a consequence of this upward HEAT transfer, additional infrared radiation takes place in the air column by virtue of it being warmed. This initially starts as spherical emission and absorption, but as the air progressively thins upwards, absorption slows, and that radiation ultimately escapes directly to space. Thus, the infrared radiation observable from space has complex sources from various altitudes, but has no labels to say where it came from, making some of the attributions “difficult”.
DISCUSSION; So what to make of this?
The initial isotropic S-B surface emission, (Trenberth’s global 396 W/m2), would largely be absorbed by the greenhouse gases instantaneously near the surface. (ignoring some escaping directly to space through the so-called “atmospheric window”). However, a large proportion of the initial S-B 396 surface emission would be continuously lateral, at the Trenberth imposed constant conditions, without any heat transfer, and its horizontal vectors CANNOT be part of the alleged 396 vertical flux, because they are outside of the vertical field of view.
After the initial atmospheric absorptions, the S-B law, which applied initially to the surface, no longer applies to the air above. (although some clouds are sometimes considered to be not far-off from a black body). Most of the air’s initial absorption/emission is close to the surface, but the vertical distribution range is large, because of considerable variation in the photon free path lengths. These vary with many factors, a big one being the regional and more powerful GHG water vapour level range which varies globally between around ~0 to ~4%. (compared with CO2 at a somewhat constant ~0.04%). The total complexities in attempting to model/calculate what may be happening are huge and beyond the scope of this here, but the point is that every layer of air at ascending altitudes continuously possesses a great deal of lateral radiation that is partly driven by the S-B hemispherical 396, but cannot therefore be part of the vertical 396 claimed in Figure 1.
CONCLUSIONS:
The vertical radiative flux portrayed by Trenberth et al of 396 W/m^2 ascending from the surface to a high cloud level is not supported by first principle considerations. The S-B 396 W/m^2 is by definition isotropic as also is its ascending progeny, with always prevailing horizontal vector components that are not in the field of view of the vertical. The remaining vertical components of EMR from that source are thus less than 396 W/m^2.
It is apparent that HEAT loss from the surface via convective/evaporative processes must add to the real vertical EMR loss from the surface, and as observed from space. It may be that there is a resultant of similar order to 396 W/m^2, but that is NOT the S-B radiative process described by Trenberth.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
ADDENDUM FOR AFICIONADOS
I Seek your advice
In figure 5 below, note that the NIMBUS 4 satellite data on the left must be for ALL sources of radiation as seen from space, in this case, at some point over the tropical Pacific. The total emissions, amount to the integrated area under the curve, which unfortunately is not given. However, for comparison purposes, a MODTRAN calculator, looking down from 100 Km gives some interesting information for the figure, which is further elaborated in the tables below. Unfortunately the calculator does not give global data or average cloud/sky conditions, so we have apples and pears to compare, not only with Nimbus, but also with Trenberth. However, they all seem to be of somewhat similar order, and see the additional tabulations.
| Compare MODTRAN & “Trenberth”, looking down from 2 altitudes, plus Surface Temperature | ||||
| Location | Kelvin | 10 metres | 100 Km. | (Centigrade) |
| Tropical Atmosphere | 300K | 419 W/m^2 | 288 W/m^2 | (27C) |
| Mid-latitude Summer | 294K | 391 W/m^2 | 280 W/m^2 | (21C) |
| Mid-latitude Winter | 272K | 291 W/m^2 | 228 W/m^2 | (-1C) |
| Sub-Arctic Winter | 257K | 235 W/m^2 | 196 W/m^2 | (-16C) |
| Trenberth Global | 288K ? | 396 W/m^2 | 239 W/m^2 | (15C ?) |
| Compare MODTRAN & “Trenberth”, looking UP from 4 altitudes: W/m^2 | ||||
| Location | From 10 m | From 2 Km | From 4Km | From 6Km |
| Tropical Atmosphere | 348 | 252 | 181 | 125 |
| Mid-latitude Summer | 310 | 232 | 168 | 118 |
| Mid-latitude Winter | 206 | 161 | 115 | 75 |
| Sub-Arctic Winter | 162 | 132 | 94 | 58 |
| Trenberth Global | 333 Shown as coming from high cloud area (= BS according to MODTRAN) | |||
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Bob Fernley-Jones says:
November 7, 2011 at 5:36 pm
G. Karst @ur momisugly November 7, at 9:18 am and Wayne
I had a quick look at Nasif’s article, “Recycling of Heat in the atmosphere”, which included in part:
This kind of analyses shows a strange “multiplication” of the heat transferred from the surface to the atmosphere and from the atmosphere to the surface which is unexplainable from a scientific viewpoint. The authors of those diagrams adduce that such increase of energy in the atmosphere obeys to a “recycling” of the heat coming from the surface by the atmosphere …
As an old fart engineer myself, I found his reference to HEAT a bit inapproriate. Trenberth shows up-and-down EMR, which is a different form of energy to HEAT, in the classical sense, with quite different behaviour. Certain physicists and climatologists seem to have defined a new meaning for heat in recent times; that it is ONLY thermal energy IN TRANSIT. Not so in engineering, and even the IPCC, NOAA and others don’t seem to have caught-up with it. For example, see these links discussing heat content:
Also, they now define heat as the net exchange of photons, i.e., they have given every photon thermal properties so that heat also flows from colder to hotter. This they say still obeys the 2nd law, that it is the net exchange of these which gives the flow always hotter to colder. They have no explanation of the mechanism in place which results in this obeying the 2nd Law. Having no such mechanism, there is nothing to stop the heat flow from colder to hotter overwhelming in the exchange and thus breaking the 2nd Law.
This “net” is their justification for ‘atmospheric background upwelling from Earth back-radiating and heating up the Earth further.’ Some no longer defend that, saying instead that it is the ‘blanket qualities of CO2 trapping heat slowing the heat loss from that upwelling from Earth, the more CO2 the thicker the blanket the more heat gets trapped in the atmosphere’.
In other words, to them all EMR is the same, claiming all photon energies create heat on being absorbed. They have jettisoned the classic differences between Light and Heat which is how they get to claim Light, Solar (UV/Visible/Nr Infrared) the actual electromagnetic energies which physically converts to heat land and oceans. They claim that Thermal Infrared direct from the Sun doesn’t even reach the Earth’s surface and so plays no part in physically heating land and oceans, the only thermal infrared in their models is that which is upwelling from Earth after being heated up by Light, and this back-radiating/being trapped.
They have no idea what they are talking about.
Paradoxes have some logic, there is no logic in their claims because they swap properties around and take laws out of context.
You’re arguing against these physically impossible basic premises as if they are real and then wonder why their arguments don’t make sense..
Bob,
“Well yes, sort of, but the real point was that Trenberth shows the vertical flux as 396, but it can’t be when a significant part of the 396 is horizontal and therefore not vertical. (the horizontal stuff is constant under Trenberth’s uniform conditions)”,
Forgive me, but I’m still not quite I understand what you mean here. The radiative flux emitted by the surface is an upward flux in the direction of space (i.e the TOA), is it not? Now, I do realize that some of the surface is not perfectly perpendicular to space, so not all the radiative flux from the surface is emitted perfectly straight up, but this would be negligible relative to the total upward flux, especially given over 2/3rds of the surface is water.
Or am I still misunderstanding you?
In other words, they have actually excluded the real heat from the Sun from the direct downwelling from Sun to Earth and they have given the property of this heat, the Sun’s real thermal energy, to the Shortwave Solar energies (UV/Visible/Near Infrared) direct from the Sun to Earth, the mnemonic meme: Shortwave in Longwave out. They have not only missed out the real heat from the Sun, whatever amount of energy that actually is, but by giving this property to Shortwave which it doesn’t have, they are short of the real thermal energies direct to Earth from the Sun, THIS is the only missing heat worth looking for..
If, the energy budget is ‘energy from the Sun to Earth which should equal the energy from Earth to Sun’, then their energy budget is junk because they’re missing the actual heat from the Sun from their calculations, and so are your calculations all who are arguing as if their energy budget figures from the Sun are real physics.
What we really have – there is energy from the Sun direct to Earth which is Heat, that is, the actual thermal energy of the Sun radiating to Earth and heating up directly, land, oceans, and us critters and cabbages which is thermal infrared, longwave, and, there is Solar energies from the Sun, Light, shortwave, which is taken in by the land and oceans and us critters and cabbages which does not directly heat these, but, which in being utilised within the processes of life on Earth can also produce heat. For example in photosynthesis, the Light energies are chemical not heat creation, the creation of sugars, but once the sugars are burned by the plant for energy in growth this produces heat, which the plant transpires in the process. When the confusion creation by their science fiction is sorted, when Light is given back its own properties which does not include Heat, these energies can also be seen to produce more non-thermal lights in their electronic transition absorptions, in reflecting/scattering in the atmosphere for example. So:
There are two main distinct processes at work in any real energy budget. Downwelling direct from the Sun to Earth must include all energies and the direct upwelling from the Earth must then balance with the all downwelling direct from the Sun, is the premise being worked to. How this direct upwelling of Heat from the Earth is apportioned to the real Light and Heat energies direct from the Sun to Earth is what the real question is. Since not all photons are thermal, Light is not Heat, not all the upwelling direct from the Earth is Heat, some of it is Light, that reflected from the surface or from light produced on Earth, fires, cities aglow at night with electric light… And being Light and not Heat, it will not heat the atmosphere in upwelling from Earth, any more than it heats the atmosphere on the way down from the Sun; the Visible Light energies absorbed by the electrons of the molecules of oxygen and nitrogen in the atmosphere are reflected/scattered which does not create heat, because visible is not hot, it is not heat, it is not thermal, it is not capable of moving molecules to vibrational states which creates heat, but, it is still in the budget of the energies from the Sun upwelling if a straight energy balance is established.
Their more than wobbly definition of Heat arose to better promoted their agenda, which was to provide a scientific sounding base to push the AGW agenda. No internal consistency is required, the object is to confuse not enlighten.
Myrrh,
“Also, they now define heat as the net exchange of photons, i.e., they have given every photon thermal properties so that heat also flows from colder to hotter. This they say still obeys the 2nd law, that it is the net exchange of these which gives the flow always hotter to colder. They have no explanation of the mechanism in place which results in this obeying the 2nd Law. Having no such mechanism, there is nothing to stop the heat flow from colder to hotter overwhelming in the exchange and thus breaking the 2nd Law.”
There’s no violation of the 2nd law with the greenhouse effect or additional CO2 induced warming because its not about energy going from cold to hot through a conduction process. Do you actually think that a re-emitted photon cannot travel from the colder atmosphere toward the warmer surface? If yes, how do the photons from the Sun travel through the colder space and then through the colder atmosphere to the surface of the Earth? EM radiation emitted in the atmosphere does not have a temperature or thermal energy. It’s only when EM is absorbed by matter that the energy gets transferred into heat or thermal energy (i.e. absorbed by a GHG molecule and transferred to the other more abundant gas molecules in the atmosphere via collisions, which heats the atmosphere).
Don’t forget that the Sun is constantly adding energy to the system. The colder atmosphere is not heating the surface – it’s reducing the rate the incoming energy from the Sun, which is mostly transparent through the atmosphere, can leave the system.
The GHE in principle is not much different than the interior of a car heating up inside on cold day from sitting out in the Sun. The Sun’s energy is mostly transparent through the windows. It’s then absorbed and re-radiated by the interior car components. The rate at which the energy is entering the interior is faster than the rate the re-radiated energy can leave the interior; therefore, the interior has to heat up. The colder exterior components of the car are not heating the interior – they are slowing heat loss.
“This “net” is their justification for ‘atmospheric background upwelling from Earth back-radiating and heating up the Earth further.’ Some no longer defend that, saying instead that it is the ‘blanket qualities of CO2 trapping heat slowing the heat loss from that upwelling from Earth, the more CO2 the thicker the blanket the more heat gets trapped in the atmosphere’.
In other words, to them all EMR is the same, claiming all photon energies create heat on being absorbed. They have jettisoned the classic differences between Light and Heat which is how they get to claim Light, Solar (UV/Visible/Nr Infrared) the actual electromagnetic energies which physically converts to heat land and oceans. They claim that Thermal Infrared direct from the Sun doesn’t even reach the Earth’s surface and so plays no part in physically heating land and oceans, the only thermal infrared in their models is that which is upwelling from Earth after being heated up by Light, and this back-radiating/being trapped.”
The use of the word ‘trapped’ is an all too common misnomer. No energy is ‘trapped’ – its exit from the system is just delayed (and not delayed very long). In effect, the re-emitted downward half of the isotropic radiative emission in the atmosphere keeps the surface warmer by re-directing some of it back in the direction of the surface, slowing the rate at which the incoming energy from the Sun can leave the system.
For example, having reduced everything used in their climate base premises to gobbledegook they can make claims such as the following:
No it doesn’t, because they have excluded the thermal infrared direct from the Sun to Earth which really heats the Earth and this is what is, logically, actually being measured, at least majority. The only sensible measurements of ‘background radiating back to Earth from the atmosphere’ have to be minus the direct from the Sun thermal infrared they’ve excluded. They could try night time..
My conclusion is, that y’all arguing against their energy budget figures are going to continue to go around in circles until you get to grips with how they have mangled the basic physics premises in their energy budget.
They are giving the properties of Heat to Light, this is AGWScience Fiction. Saying that: Light, sunlight, shortwave, is now thermal. That this Light passes through the atmosphere unabsorbed. That this Light heats oceans. That this Light directly heats the Earth. That Heat, thermal infrared, direct from the Sun does not heat the Earth.
In the real world of physics: Light is not Heat. Light is not thermal. Light does not pass through the atmosphere unabsorbed. Light does pass through water unabsorbed. Light does not directly heat the Earth. The Sun’s Heat, thermal infrared which is the thermal energy of the Sun on the move to Earth, does directly heat the Earth.
Without directly dealing with their fictional base premises, arguing about what the ‘backradiating’ infrared is doing and what they haven’t included and so on, is a complete and utter waste of your time.
RW says:
November 8, 2011 at 6:50 pm
Myrrh,
“Also, they now define heat as the net exchange of photons, i.e., they have given every photon thermal properties so that heat also flows from colder to hotter. This they say still obeys the 2nd law, that it is the net exchange of these which gives the flow always hotter to colder. They have no explanation of the mechanism in place which results in this obeying the 2nd Law. Having no such mechanism, there is nothing to stop the heat flow from colder to hotter overwhelming in the exchange and thus breaking the 2nd Law.”
There’s no violation of the 2nd law with the greenhouse effect or additional CO2 induced warming because its not about energy going from cold to hot through a conduction process. Do you actually think that a re-emitted photon cannot travel from the colder atmosphere toward the warmer surface? If yes, how do the photons from the Sun travel through the colder space and then through the colder atmosphere to the surface of the Earth? EM radiation emitted in the atmosphere does not have a temperature or thermal energy. It’s only when EM is absorbed by matter that the energy gets transferred into heat or thermal energy (i.e. absorbed by a GHG molecule and transferred to the other more abundant gas molecules in the atmosphere via collisions, which heats the atmosphere).
Heat is transferred by radiation, you have excluded that just as you have excluded the thermal energy from the Sun directly heating Earth. You don’t understand the difference between Heat and Light because you are repeating science fiction memes, not real physics.
There are three ways heat is transferred, by conduction, convection and by radiation. It is actual thermal energy travelling to us from the Sun, not indistinguished ‘photons of electromagnetism’ which then somehow create heat when absorbed.
The Visible light from the Sun is absorbed by the atmosphere. It is absorbed by the electrons of the molecules of oxygen and nitrogen, this is what reflection/scattering is, this is why the sky is blue (blue light being smaller and even more nervy than red visible, gets scattered and bounced around the sky more easily), this is categorised as electronic transitions. Electronic transitions work on the smaller electron level of molecules, they are not powerful enough to move the whole atom or molecule into vibrational states which is how matter is heated
But, since you claim that visible photons absorbed create heat, how much heat does this create in the molecules of oxygen and nitrogen in our atmosphere? Where is this in your energy budget?
You are repeating science fiction memes, that’s why there is no logical consistency in your physics. Your memes do not describe the real physical world around us.
The thermal energy of the Sun is Heat. That thermal energy of the Sun is transferred direct to the Earth by radiation, one of the three methods of Heat transfer. That thermal energy from the Sun in radiation is thermal infrared. It is the actual heat from the Sun on the move to us. It is invisible. We can feel this heat radiating out from hot pavements, stoves and so on, which do not have any visible light. It is a powerful energy. It is greatly absorbed by water. Heat, thermal infrared radiation, penetrates your body and heats the molecules of water in your body, our bodies are mostly water (and around 20% carbon). Heat warms us up from the inside.
Light, does not do this.
“The GHE in principle is not much different than the interior of a car heating up inside on cold day from sitting out in the Sun. The Sun’s energy is mostly transparent through the windows. It’s then absorbed and re-radiated by the interior car components. The rate at which the energy is entering the interior is faster than the rate the re-radiated energy can leave the interior; therefore, the interior has to heat up. The colder exterior components of the car are not heating the interior – they are slowing heat loss. ”
This NOT what causes the heating inside a car. The heat generated inside the car is induced by the original insolation upon the surfaces inside the car. The windows serve to trap the hot air which is then generated by conduction with the surfaces. This is how a real greenhouse works, and it is NOT “in principle” the same way the atmospheric greenhouse is claimed to work. The rate at which energy leaves the interior will eventually equilibrate with the rate of energy coming into the interior – at this point there is radiative thermal equilibrium. This is just like the radiative thermal equilibrium with the Sun which keeps the Earth at -18C on average. The car will NOT become hotter inside than the insolation inducing the temperature upon the surfaces, just like the Earth is NOT hotter than -18C on average. The radiative temperature of the Earth IS -18C as measured by satellites in outer space. The surface temperature specifically – a very small component of the entire ensemble – is supposed to be warmer than the average due to the natural sorting of the temperature of a gas in a gravitational field.
So you see here in the quotation above the prototypical example of illogic and paradox in the GHE paradigm. Note the wording: “The ghe is [IN PRINCIPLE NOT MUCH DIFFERENT]…” Alright, “in principle”. But in reality, a real greenhouse does NOT work by trapping radiation, but by trapping hot air and preventing its convection. A real greenhouse is warmed by the direct and original insolation into it. So then the argument becomes a description of something that ISN’T. We describe a greenhouse to work a way that it DOESN’T, in order to say this establishes the desired GHE in the atmosphere. We argue like this nowhere else in physics.
The goal here, obviously then, is to invent some radiative scheme by which CO2 can be blamed. That’s the entire purpose of this paradigm. CO2 does not prevent convection. If it could prevent convection, THAT would be away in which it behaved similar to a greenhouse. But CO2 is a negligible component of the atmosphere…it does not prevent convection.
The vast majority of heat in the atmosphere is gained by direct conduction with the heated ground surface; the second majority is achieved by direct heating from insolation due to the extinction of sunlight. And CO2 has one more degree of freedom that the entire rest of the 9(% of the atmosphere doesn’t have: it can shed heat by radiating it away via a molecular vibration. All the other gases in the atmosphere just get heated and then hang on to it, unable to shed it away by radiation. CO2, as a radiating gas, has a much easier time shedding the energy it collects. So neither does CO2 prevent convection, it also doesn’t prevent radiation! It’s able to radiate (cool) when the rest of the atmosphere CAN’T.
Illogic and paradox IS the paradigm of climate science and the GHE. One best example is the question as to lag of CO2 to temperature in the ice-core records – the answer being, from Gavin Schmidt: just because CO2 didn’t cause the start of the warming, doesn’t mean it didn’t cause the rest of it.
It was that statement that turned me into a skeptic – read, proper scientist – and I have never found a solid line of logic or reasoning to welcome me back to the AGW cause.
RW November 8, at 6:01 pm
Forgive me, but I’m still not quite I understand what you mean here. The radiative flux emitted by the surface is an upward flux in the direction of space (i.e the TOA), is it not? Now, I do realize that some of the surface is not perfectly perpendicular to space, so not all the radiative flux from the surface is emitted perfectly straight up, but this would be negligible relative to the total upward flux, especially given over 2/3rds of the surface is water.
Or am I still misunderstanding you?
Well; Trenberth’s 396 is primarily based on an S-B calculation of a daft assumed global-year average surface temperature and stuff. By S-B definition, this is not a vertical flux, but isotropic. If the atmosphere were transparent then it would all radiate directly to space, in which case by integration it could effectively be described as a vertical flux. However, much of the radiation tends towards the horizontal or tangential to the surface, but is annihilated by absorptive gasses and stuff. Thus the horizontal vector components do not make it to space, but are still part of the 396, but not in the field of view of the vertical. (normal view). Thus these horizontal vector components should be vectorially deducted from the hypotenuse of the standard vector diagram to give the vertical component.
See item 5) in the article, and also next, a quote from a comment I made to Tim Folkerts on 3/Nov:
All this ignores whatever radiation that may be escaping directly to space, including that from “convective” stuff.
Bob,
“Well; Trenberth’s 396 is primarily based on an S-B calculation of a daft assumed global-year average surface temperature and stuff. By S-B definition, this is not a vertical flux, but isotropic.”
This is what I still don’t understand. Yes, the body of the Earth as a whole emits radiation from its surface in all directions out to space because it’s a sphere, but the emission from the localized surface itself is not isotropic but more or less straight up to space.
Now, it’s true that the spherical curvature of the Earth would have a slight effect on the isotropic emission from the atmosphere, as tiny fraction (1% or less) of the more sideways downward half would go over the horizon, but again the amount is negligible. I don’t think this is what you’re referring to though, is it?
Bob,
“See item 5) in the article, and also next, a quote from a comment I made to Tim Folkerts on 3/Nov:
Concerning your belief that a photon stream cannot be analysed with component vectors, please see this brief summary of Lambert’s cosine law. It is written from the perspective of optics, and you may not like the semantics. However, if you look at the far right of figure 1, see how when the incoming light is at a shallow angle it is “reflected” less but still isotropically. This is because the vertical component is small, whereas the horizontal, which cannot be absorbed or reflected, is a large proportion of the light stream.
http://escience.anu.edu.au/lecture/cg/Illumination/lambertCosineLaw.en.html
All this ignores whatever radiation that may be escaping directly to space, including that from “convective” stuff.”
I’m not following this. The radiation entering Earth’s surface, either from the SW directly from the Sun or from the LW from the atmosphere, is all absorbed and re-radiated — not reflected. Are you trying to say that radiation from one side of a flat surface is multi-directional over a 180 degree plane?
Bob!! I’m jumping up and down with glee! Someone finally sees that aspect clearly, for your words are now as I would speak them myself. I feel like taking a break and passing the baton to you, you seem to explain it better than I to others, no one has undestood me in nine months.
After reading what you just said to RW, there is one point you might be sure to include in your description… that near horizontal radiation from the surface, that would have to pass through some 50 km of atmosphere to make it to space, of course, will be absorbed at some point, being IR and passing through such a great amount of mass. This cools the spot where the radiation was released and warms where it is absorbed, BUT, the opposite is always occurring from that far point back to the point of initial radiation but a tiny residual exists for 89 degrees from vertical is not exactly horizontal, but close. Since all atmospheres have a lapse rate that far point will be some amount ABOVE the surface where it is cooler and that far point will never pass the same amount back to the initial point by symmetry. That tiny difference when integrated across all directions in the hemisphere (degrees from vertical) will end up being the 63 Wm-2 (actually exactly 1/6) you began this post with (396-333).
And, we are not just speaking of 89 degrees from vertical, that was just an exaggerated example, but the same occurs for any degree you pick but the parameters will flex of course. If at 60 degrees it would have to pass through twice the mass to escape. The rest is geometric adjustments.
What I’m saying is don’t forget the symmetrical passing back and forth at all points and in all directions or someone will pick on that very point to create a meaninglessly argument. It is this back and forth, cooling when emitted, warming when absorbed that causes the cancellation of the energy transfer by symmetry, not of the energy itself of course!
I always like to equate that to what is happening in any room you happen to be siting in, the back and forth between the walls at the same temperature. Some see gazzilion photons flying back and forth from all points at all times in all directions even if temperatures are identical, so let them, for that view does not really change anything we have been discussing, just a different way to look at the same thing. (Actually I personally don’t even “believe” that of photons, if real at all, for it is more of a standing wave between any two points if at identical temperatures, there is no physical reason, even at the microstate level, for the spontaneous emission to even occur at all (again, see Hans physics link on that subject, and I thank him for that, and at such a perfect time)). But discussion on that get to deep for here.
RW @ur momisugly November 8, at 8:23 pm AND 8:36 pm.
It was experimentally determined by Stefan that a small flat surface radiates isotropically, (hemispherically), and Boltzmann later derived the formula mathematically. (via integration of Planck distribution and solid angles). As far as I’m aware, this is well accepted by the scientific community, although it should probably only apply on a small scale when in an absorbent atmosphere including the Earth’s surface; a single body situation. When there is an interaction between two bodies it becomes complicated by relative geometry and field-of-view considerations. When there is interaction between a body or bodies and an absorptive gas, it appears to be a bit of a mystery in the literature. (and certainly to me). In general engineering, the field of view between two or more bodies is sensibly all that is considered in the earthbound scale of things.
See also items 1), 2), & 3) in the article
One thing that should be noted from the diagram at the top of this article is that 396 W/m² is leaving the Earth’s surface in the form of LWIR and there is 333 W/m² coming right back from the atmosphere. As indicated by the author, this says that only 63 W/m² is actually escaping from the surface by LWIR and the 333 W/m² represents a trapped local energy flowing up and down. The 40 W/m² figure would seem to be bogus or unexplained.
Assume that the 333 W/m² number represented the energy flowing downward as observed one micrometer above the surface. In that case, there is no consideration of energy flowing sideways. 63 W/m² must be leaving the surface. Once that energy gets into the atmosphere, it can go anywhere it wants as long as it does not change the observed energy readings flowing up or down.
The figure also says that 239 W/m² is actually escaping from the Earth. This would suggest that the additional 176 W/m² must be radiated by the atmosphere. The atmosphere cannot be creating this flow except as it is warmed by the Sun and the Earth. The diagram also says that thermals and evaporation result in a energy flow of 97 W/m² from the surface into the atmosphere. Thus, solar heating must be adding 79 W/m² to the energy in the atmosphere. The diagram says this is 78 W/m², so there is only a 1 W/m² missing energy flow. The net total energy flow from the surface would thus be 160 W/m² escaping as LWIR to outer space. The diagram says 161 W/m² is arriving as non-reflected solar energy. Again, there is a 1 W/m² discrepancy. Perhaps this is covered by the unexplained “Net absorbed 0.9 W/m².”
Note that one can use the University of Chicago hosted MODTRAN utility to get a picture of Air Force model *predicted* radiative heat flow in the atmosphere by changing the sensor altitude settings and subtracting the down flowing energy (sensor looking up) from the upward flowing energy (sensor looking down) to measure the ‘outward energy flow’ at levels in the atmosphere up to 99 km. MODTRAN results nominally apply to energy flows over the wavenumber range of 100 to 1500 kayzers (cycles per centimeter, CM-1).
wayne @ur momisugly November 8, at 10:23 pm
Wayne,
Concerning your doubts about wave-particle duality theory, if you do a Google search on:
photon two-slit
There is some interesting stuff, such as:
http://en.wikipedia.org/wiki/Double-slit_experiment
Bob, I’m well aware of the double-slit experiment and the duality. Don’t take me wrong, it’s just that I have also read some hundred papers, books, discussions in physics over the years with some very good physicists knowing worlds more than myself on the subject, both sides. I’ll talk photons, use them, and they are great way to have others visualize the quantization of energy, but, firm “belief” they concretely exist only as photons and no waves… I have seen no conclusive experiment results that such particles actually exist, as some physicists have pointed out, possibly just mathematical and statistical in nature, maybe not. In that subject lie some other very interesting paradoxes. But I didn’t mean anything negative, use them, I do.
You know, if someone were to design an experiment that proved light was actually just E/M waves and why they appear to be particles, it wouldn’t surprise me. Same on the flop side. As far as I know the duality still exists, really. Or… maybe I just missed the true answer somewhere along the way. ☺
Bob asks “So, you are claiming that ½ + ½ + ½ + ½ + ½ + ½ = 1 ?”
Suppose 100,000 people leave a stadium after a big game, driving out across the state to their homes. After tracking the people to their homes, i discover that
* 50,000 end up north of the stadium; 50,000 end up south of the stadium.
* 40,000 end up east of the stadium; 60,000 end up west of the stadium.
* 70,000 end up at a higher elevation than the stadium; 30,000 at a lower elevation
I’m sure neither of us thinks 300,000 people left the big game.
People are not vectors; photons are not vectors. A single photon can head east, north and up, being counted in each group. Even if it is heading more east than up, it is still heading up (as opposed to down).
Now, you could divide the photons into those heading more vertical (either up or down) than horizontal, in which case the first group has 2/6 of the photons and the other group has 4/6 of the photons. But the 4/6 that are “mostly sideways” still are divided in half as either generally upward or generally downward. No matter how you slice it, 1/2 of the isotropic radiation from a chunk of atmosphere is upward and 1/2 is downward. Not matter how you slice it, ALL of the photons from a flat part of the earth’s surface have an upward component and carry energy upward (at least until some get absorbed by the atmosphere.
Bob,
“It was experimentally determined by Stefan that a small flat surface radiates isotropically, (hemispherically), and Boltzmann later derived the formula mathematically. (via integration of Planck distribution and solid angles). As far as I’m aware, this is well accepted by the scientific community, although it should probably only apply on a small scale when in an absorbent atmosphere including the Earth’s surface; a single body situation. When there is an interaction between two bodies it becomes complicated by relative geometry and field-of-view considerations. When there is interaction between a body or bodies and an absorptive gas, it appears to be a bit of a mystery in the literature. (and certainly to me). In general engineering, the field of view between two or more bodies is sensibly all that is considered in the earthbound scale of things.
See also items 1), 2), & 3) in the article”
Very interesting. I have to admit I’ve never really given this much thought, but I think Tim Folkerts is likely correct when he says “Not matter how you slice it, ALL of the photons from a flat part of the earth’s surface have an upward component and carry energy upward (at least until some get absorbed by the atmosphere).”
I think the same could be said of the upward half of isotropic emission from the atmosphere itself that passes into space. It’s not all going straight out to space perpendicular to the surface, but it’s going in a direction that goes out to space, which is what really matters in the end.
Tim, no one said a photon is a vector. No one said you can split a single photon. However, it was said that a photon’s movement, or e/m wave, is a vector, you know, energy transfer. It seems you are having trouble following what has been said above. Perhaps a detailed re-read might help.
Wayne says:
>However, it was said that a photon’s movement, or e/m wave, is a vector, …
Yes. Fine.
>… you know, energy transfer.
Nope. You slipped up. A transfer of energy is NOT a vector and cannot be compared with things like the direction of the photon. If 1 liter of gasoline enters my gas tank at any angle, then 35 MJ of energy enters. The movement of the gasoline is certainly a vector, but the energy transferred is not. If 396 J of photons pass thru a surface at 45 degrees, 396 J of energy is transferred. Energy transfer is NOT a vector.
That said, I agree there are many aspects of vectors that are indeed important in the analysis here. The directions of the photons must be accounted for when determining how many photons actually end up reaching a particular surface.
Bob says: “For instance, they show 80 leaving the surface and being released as latent heat, (the same value), in the clouds. However, this cannot be correct. The heat loss from the surface has an un-shown element known as evaporative cooling. ”
I am pretty sure the 80 W/m^2 _is_ the evaporative cooling you speak of. The surface is losing those 80 W/m^2, cooling the surface. When the water re-condenses (in clouds), the air is warmed by that amount. I’m not sure what additional cooling of the surface you are thinking of, or where that energy comes from/goes to.
Bob,
So I think I now finally understand what you’ve been saying. I think you are correct that the emission from the surface is equally multi-directional, but I think Tim F. is correct in saying it doesn’t matter because it’s still in an upward direction away from the surface toward space. For calculations and all practical net energy flux depictions from the surface to the atmosphere, it doesn’t matter, or it’s still accurate to depict it as all being emitted more or less perpendicular to the surface toward space.
Think about it from this perspective. The upward half of isotropic emission from the atmosphere itself that ultimately passes into space. It’s not all going straight out to space in a direction perpendicular to the surface, but it’s none the less going in a direction that goes out to space, which is what really matters in the end. Is it incorrect to depict this flux from the atmosphere to space as perpendicularly upward from the atmosphere?
I don’t think so.
Tim Folkerts @ur momisugly November 9, at 4:20 pm
You wrote in part:
What branch of mathematics is this, where people can travel simultaneously in several different directions up to 90 degrees apart, three dimensionally? Does it have a name? Maybe it has something to do with string-theory and multiple dimensions. Give me pause to think on this and do some research, and I’ll try and get back to you before Christmas.
Meanwhile, let me quote parts of two of mine to you that are connected:
November 3, at 5:59 pm
AND: November 4, at 10:05 pm
I can’t find a response, and would appreciate such before Christmas.
Bob says: “If the atmosphere were transparent then it would all radiate directly to space, in which case by integration it could effectively be described as a vertical flux. However, much of the radiation tends towards the horizontal or tangential to the surface, but is annihilated by absorptive gasses and stuff.”
You just agreed that in a transparent atmosphere, if 396 W/m^2 left the surface, then 396 W/m^2 would pass up thru any layer.
Let’s consider the opposite extreme — an atmosphere where each cubic meter is a perfect black body, absorbing all radiation hitting it.
So the ground emits 396 W/m^2 into a cubic meter. It all gets absorbed. The cube will emit 1/6 in each direction: 66 W/m^2 up, 66 down, and 4*66 sideways. The cube must be the right temperature to emit 66 W/m^2. And most of the energy _is_ going sideways as you deduced.
But wait, the cubes to the sides are also that temperature, so they emit 66 into the four sides. And the next cube up was getting 66, so it will return 66/6 = 11 . That is 396 + 66*4 + 11 = 671 W/m^2 inward, so there is 671/6 =112 W available to head out each 1mx1m side. Which is nearly twice as much from the second iteration as we got from the first iteration.
But wait, the cubes to the sides are returning 112, and the cube above is returning more than 11 W. There will be diminishing returns, but each iteration will get is closer to the “correct” value. It is clear that the final answer must be that each cube is hot enough to emit 396 W/m^2.
The cube at the bottom of the stack gets only 396 W/m^2 from the ground below. But it also gets 396 W/m^2 from the cubes on the other 5 sides. It emits 396 W/m^2 in every direction — INCLUDING UPWARD. So while it emits much more from the 4 sides than it does up or down (which I think was your original point), it also GETS much more from the sides that it gets from below, leaving it with sufficient power to radiate a full 396 W/m^2 upward, even though only 66 W/m^2 “of the energy attributable to the ground below” is actually still heading upward.
(I’m trying to decide if the previous discussion is too obvious, or to obscure!)
So in a perfectly transparent atmosphere, 396 W/m^2 is left to exit from the layer of atmosphere 1 m high around the surface of the earth.
And in a perfectly opaque atmosphere, 396 W/m^2 is left to exit from the layer of atmosphere 1 m high around the surface of the earth.
It ought to be intuitive that for any level of opacity in between, 396 W/m^2 is left to exit from the layer of atmosphere 1 m high around the surface of the earth.
[NOTE: this assumes no temperature gradient. In fact, the observed gradient would require that the top of he cube be cooler than the bottom. So the “true” radiation from the bottom cube would be more like 396 down, 395 up, and 395.5 to each side.
But to repeat, this decrease is due to lapse rate, not because “most of the radiation is going sideways rather then up or down”.]
Tim:
… Energy transfer is NOT a vector. …
Ok, we are clearly talking on two different planes of thought. I see the way you are thinking, will you stop see what Bob and I have speaking of. You look at energy transfers as a lump quantity (energy, Joules) the is added to a bucket or point irregardless of where that energy came from or even the direction. I can see that and in certain discussions that would be proper and what I would speak of in that case too.
But addressing what has been said above, using your example (using water, not gasoline), if you are tracking the droplets of water from various directions the transfer of a drop of water from point A to point B (the bucket) is vectors of quantum of energy being transferred and I know you know enough to see that (I hope). That is the transfer we have been speaking of. Most still here seems well enough versed in basic physics to understand those two different aspects of “energy transfer”.
Does that clarify it?
Bob asks “What branch of mathematics is this, where people can travel simultaneously in several different directions up to 90 degrees apart, three dimensionally? ”
Are you really confused by this???
Suppose my house is 40 miles from the stadium at a heading of 10 degrees east of north, and 200 ft higher in elevation. Then I would be counted as living north of the stadium. I would be counted as living east of the stadium. I would be counted as living higher than the stadium. The vector describing the location of my home has components in each of these directions.
If a stream of photons is heading 10 degrees east of north, and 5 degrees above the horizontal, then these photons are counted as heading north. These photons are counted as heading east. Most importantly, they are counted as heading upward. If this stream has 1 W of photons leaving the surface, it will have 1 W heading up thru any layer higher up. I don’t need to know ANYTHING other than the initial direction is more upward than downward (assuming again a transparent atmosphere).
~~~~~~~~~~~
As for the Lambertian reflection/emission, I have no problem with it. And I have no problem describing the direction or the momentum of a photon with vectors.
I just don’t see how it is important here. Lambertian reflection is an idealization. If a beam of IR photons or sunlight hit such a surface, they would reflect uniformly in all directions. But we are not hypothesizing any such surfaces for EMR to reflect from.
It turns out that black bodies are perfect lambertian emitters, but we are already assuming that IR from the surface is isotropic, so saying that the surface can ALOS be described as a Lambertian emitter seems superfluous.