If there were no atmosphere on top of our solar-heated terrestrial surface, then Earth’s mean global surface temperature would likely be about 80 degrees lower than what it actually is (209 rather than 289K). And this would be in spite of the fact that in this case the solar heat input to the global surface would be almost 80% larger on average (296 rather than 165 W/m2).
Much of this cooling of the mean would simply come as a result of greatly amplified temperature swings between day and night and between the seasons. The larger the planetary surface temperature amplitudes in space and time, the lower the mean global planetary surface temperature needs to be to maintain dynamic radiative equilibrium with the Sun. This is why the Moon is so cold.
So we need to get this straight: The Earth’s surface would be a much colder place without an atmosphere on top of it. Even with much more solar heat absorbed. There is no escaping this. The lunar surface is about 90K colder than ours, on average.
SO WHAT DOES OUR ATMOSPHERE DO?
The short answer: It insulates the solar-heated surface.
Well, so how does it do this?
Mainly in four ways, three of which concern suppressing the effectiveness of convective cooling of the surface at a certain temperature.
Why is this important? Why convective cooling?
Consider a hypothetical single-room house. The room is evacuated (no air) and completely and evenly insulated on all sides by a 0.25 m thick wall of say balsa wood (thermal conductivity (k): 0.048 W/m K), a strong lumber of low density (containing lots of pockets of air). In the middle of the room there’s a tiny oven burning steadily from a constant supply of fuel. The house’s surroundings are also a vacuum, just like the room inside, only the outside vacuum is boundless, like space. The emissivity of both the inner and the outer surfaces of the wall is assumed to be 1 (like a blackbody).
Now, the tiny central oven, the only heat/energy source in this setup, burns so that the temperature of its outer surface facing the inner walls of the room naturally adjusts to emit the same isotropic flux of radiant heat at all times towards the walls, meaning that if the temperature of these walls rises, the temperature of the outer surface of the oven must also rise accordingly.* When this constant radiant heat flux reaches and is absorbed by the inner surface of the balsa-wood wall, its mean intensity is 240 W/m2.
*See the earlier discussion of how and why this must be here.
In order for the temperature of the inner surface of the house’s wall facing the evacuated room surrounding the tiny central (and constantly burning) oven to stop rising, that is, for it to reach a dynamic equilibrium with its heat source (the oven) and thus its steady-state temperature, its mean heat input (Qin) – 240 W/m2 – needs to be matched by its mean heat output (Qout). Since the heat output from an object can never in nature move in the direction of its heat input, this means that, in the steady state, 240 joules will have to pass each second through each square metre of wall, 0.25 m on to its outer surface, facing space. This particular heat transfer can in effect only occur by way of conduction (there could also be radiation moving the energy forward through the internal air-filled cavities, but we’ll assume this transport, for the sake of argument, to be fully negligible).
Now, since the outer surface of the house’s wall faces the vacuum of space, it can only deliver its heat to it via radiation. And since, in the steady state, the heat delivered from the outer surface of the house’s wall to space will have to match the heat supplied to it through the wall from the wall’s inner surface, facing the oven, its steady-state temperature (according to the Stefan-Boltzmann law) will need to be 255K.
The question then is: If the inner wall surface absorbs (and passes on) a heat flux worth of 240 W/m2 (radiative IN, conductive OUT) and the outer wall surface absorbs (and passes on) a heat flux of the exact same size (conductive IN, radiative OUT), at a steady-state temperature of 255K, what is required for the 240 W/m2 to pass through the wall, from the inner to the outer surface?
A temperature difference across the thickness of the wall. That is, a temperature gradient.
Since heat can only spontaneously move from warmer to cooler and since the heat in this case moves from the inner to the outer surface of the wall, it follows that the inner surface, in the steady state, needs to be warmer than the outer one.
Note, just as much energy moves into and out of the inner surface as ‘heat’ as what moves into and out of the outer surface per unit of time and area. But the former is still warmer than the latter.
Ok. So how much warmer? Well, let’s see. We’ll use Fourier’s fairly straightforward conductive heat transfer equation:
Q/A = -k ∇T
where Q/A is power (J/s) per area – the power density flux or ‘conductive heat flux’: W/m2,
k is the thermal conductivity of the material/medium through which the heat is conducted: W/m K, and
∇T is the temperature gradient through the material: K/m.
We know already that the heat flux is 240 W/m2. We also know that the wall is 0.25 m thick, that the outer surface of the wall is at 255K and that the thermal conductivity of balsa wood is 0.048 W/m K.
What we want to know is the steady-state temperature of the inner surface of the wall:
240 = -0.048 * ((255 – x)/0.25)
-5000 = (255 – x)/0.25
-1250 = 255 – x
x = 1505 K
The inner surface of the wall of our hypothetical house will not reach its steady state until it has warmed to 1505 K (1232 °C).
That is pretty bloody hot! In fact, it is way too hot for balsa wood. The temperature gradient through the wall at this point would have to be -5000 K/m, a drop in temperature of 50 degrees per cm!
Why is such an incredibly steep gradient required?
Simple answer: Because balsa wood is a terrible conductor of heat. If our wall were instead made of aluminium, a light metal and a first-rate conductor, then the temperature of the inner surface would need to be no more than 0.3 degrees warmer than the outer one in the steady state for the full 240 W/m2 to be conducted right through, down a gradient of -1.2 K/m (0.012 K/cm).
In practical terms, the balsa wood walls of our hypothetical room would never be able to reach a steady state, a dynamic equilibrium between its heat input from the central oven and its heat output through to the outside. It would just continue to warm slowly, but surely, until we could no longer be bothered waiting, or until the wooden walls eventually started to shrivel and smoulder from its own hotness.
The point to take home from this exercise, this admittedly highly idealised thought experiment, is that the balsa wood, being such a poor thermal conductor, makes for a brilliant insulator:
- The less effective the heat is moved through the insulating system (the wall), from where it’s originally absorbed (at the inner surface, IN from the oven) to where it’s finally emitted (from the outer surface, OUT to space), the stronger its insulating effect, and the higher the ‘absorbing surface’ temperature needs to be in order to be able to pass the heat through the system to the ’emitting surface’ sufficiently fast to reach dynamic equilibrium between heat IN and heat OUT.
This is also the governing principle behind the ‘atmospheric insulating effect’.
As I guess most people have already understood, the hypothetical setup described above is a simple model of the ‘Sun-Earth-space’ composite system, where 1) the central oven represents the Sun (which, however, does not itself need to warm in order to supply a constant radiant heat flux to Earth as the Earth warms; it is way too far away, and far too much hotter than Earth for this to occur), 2) the vacuum between the oven and the inner surface of the wall represents space in the Sun > Earth heat transfer, 3) the inner surface of the wall represents Earth’s surface, 4) the wall proper, between its two outward-facing surfaces, represents the atmosphere (essentially, the troposphere), 5) the outer surface of the wall represents the ToA, and 6) the outside vacuum represents space in the Earth > space heat transfer.
So the atmosphere basically acts as a ‘conductive insulating layer’ – kind of like styrofoam or foam rubber – wrapped around the solar-heated surface, hindering the solar heat absorbed by the surface on its route back out to space.
The funny (?) thing is that air is an even worse conductor of heat than balsa wood. In fact, heat would conduct twice as effectively through balsa wood as it would through pure air, which at room temperature has a thermal conductivity of a mere 0.024 W/m K.
The good thing is that in an open volume of air, much larger than the tiny cavities inside the balsa wood lumber, subjected to gravity and heated from below, our atmosphere being a perfect example, a mechanism for the movement of energy emerges that is much, much more effective than the pure molecule-to-molecule conduction of heat, even immensely more effective than conduction through a slab of aluminium. It is called convection (or ‘advection’), and involves the movement of the heated medium itself (which means it only operates in fluids (liquids and gases), not in solids).
Convection – in our atmosphere – simply substitutes for (supersedes) conduction as the real ‘transporter of heat’ from (inner/lower) ‘absorbing surface’ to (outer/upper) ’emitting surface’.
However, even convection needs a temperature gradient, just like conduction, through the system in question in order to be able to do what it’s supposed to do – transfer energy from the heating end to the cooling end of the system. It can simply make do with a much, much gentler one …
But since, with a massive atmosphere, being able to absorb heat from the surface that was originally meant for space, the final emission of this energy back out of the Earth system will be delayed by having to go through an intermediate, internal transfer process on the way, the movement of bulk air from the surface to the atmospheric level(s) or regions from where it can be freely radiated to space, the ‘absorbing surface’ – the solar-heated liquid/solid surface of the Earth – will by natural necessity end up warmer than the ’emitting surface(s)’ aloft in the atmosphere.
To illustrate this, let’s go back to our strange little house in space with the balsa wood walls.
If the much more effective heat transfer mechanism of convection moved the heat through the 0.25 m wall rather than conduction, then the inner surface facing the oven (the equivalent of Earth’s surface) would not need to be anywhere near as hot for balance between heat IN and heat OUT to be achieved. But it would still need to be ever so slightly warmer than the outer surface facing the surrounding space (the equivalent of ToA or Earth’s effective radiating ‘surface’), although hardly discernible over a 0.25 m distance.
If there were no wall at all (no atmosphere), however, only the inner surface facing the surrounding space directly, then there would no longer be any need for it to become warmer than 255K. Then all its heat loss would be by radiation alone, and it would be straight from the surface itself. The ‘inner’ surface would’ve become the actual radiating surface to space.
The point here being: As soon as some of the surface energy is transferred as heat to the atmosphere rather than directly to space, be it through radiation, conduction or evaporation, a delaying process is initiated that will eventually force the steady-state surface temperature up.
At this stage, people might wonder where I’m going with all this. Is he actually endorsing the ‘raised effective radiating level (ERL)’ explanation of the rGHE?
To this I would say: Yes and no.
I endorse the general principle behind this explanation in the broader sense already expounded above. What I do not endorse is the notion that this is somehow a consequence simply of the atmosphere’s IR-opacity. There are two major reasons for this:
- The atmosphere is not dependent on being able to absorb IR radiation from the surface for it to warm; it would’ve warmed with or without this ability, simply from being directly convectively coupled with the solar-heated surface below. The atmosphere is, however, dependent on being able to emit IR radiation to space for it to cool. Or else, energy transferred from the surface to the atmosphere would have no real means of getting out of the Earth system; it would rather pile up … be ‘trapped’ within. This is an unacceptable scenario in a real universe.
- The Earth system doesn’t actually possess a final single 2D ‘radiating surface’ to space as does our balsa wood wall. The Earth system radiates its heat to space from a full 3D ‘radiating volume‘, spanning the entire depth of atmosphere from the actual liquid/solid surface at the bottom to the ToA at the top. It is thus impossible to tie Earth’s total radiant heat flux to space to any one specific temperature. The 255K value simply becomes a mathematical construct arrived at by calculating backwards from the total flux itself.
No, as I pointed out to begin with, the ‘atmospheric insulating effect’ is very real, but it arises from the simple fact that the atmosphere is massive, not as a consequence of this atmosphere being opaque to outgoing IR as opposed to some hypothetical case where it’s not. (I’ll elaborate on this crucial point in the next post.)
As mentioned, the atmosphere suppresses the overall cooling rate of the global surface at a certain temperature by inhibiting the effectiveness of its own convective circulation, and it mainly does so in three ways. But the first thing it does is evening out the global temperature differences across the planetary surface. The thicker it is, the more evened out the temperatures become:
- The atmosphere (as does – importantly – the global ocean) reduces the surface temperature amplitudes both spatially (from equator to poles) and temporally (between day and night and summer and winter). Space doesn’t (and pure regolith does it only temporally and to a relatively minor extent). The atmosphere does this by holding on to (‘capture’ and ‘store’ for a while, significantly away from the surface itself) and spreading most of the absorbed solar heat before it’s being released back out of the system. It holds on to it through its thermal mass and latent heat. It spreads it via natural heating-induced pressure/density circulation.
- The atmosphere is warm. Space isn’t. Which means that the atmosphere basically acts as a massive thermal barrier through which surface heat needs to travel up along a certain temperature gradient constrained by gravity in order to be able to get out of the Earth system. The temperature gradient determines – to a first approximation (see points 3. and 4.) – how much the surface and, in turn, the lowermost layers of the atmosphere need to warm before effective convective cooling of the surface becomes fully operative.
- The atmosphere exerts a pressure on the surface. Space doesn’t. By having a weight (mass times gravity) and a density (mass per volume), the atmosphere presses down on the surface, restricting the average ability of water molecules to escape our global surface through evaporation, hence its main heat loss mechanism, at a particular surface temperature. Evaporation, as it happens, is a major driver of atmospheric convective circulation on Earth.
- The atmosphere is ‘sluggish’. Space isn’t. By possessing inertia and a certain inherent ‘sluggishness’ (molecular density, weight and viscosity), the atmosphere resists heating and cooling, near-surface turbulent flow and steep horizontal temperature/pressure differentials leading to strong surface wind shear, all of which would work to enhance convective surface cooling. Compare Mars and Venus. The light atmosphere of the former is so responsive and turbulent that its constant erratic fluctuations makes it hard to even settle on an average state. The heavy atmosphere of the latter, on the other hand, is almost completely non-responsive and non-turbulent (until you get very high up above the surface), the thick ‘air’ along the surface hardly moving at all, and only in a sludgy, near-perfect laminar flow. The Earth’s atmosphere sits somewhere in between these two extremes.
The atmosphere, in short, through its mass simply resting on the solar-heated surface, demands a certain kinetic level to be reached before the smooth, adequately efficient loss of surface heat is allowed. Space has no such limiting ‘blanket’ tendency, other than perhaps the speed of light …
To conclude
An atmosphere insulates like this:
- Without an atmosphere, the planetary surface equilibrates radiatively with its sun and stabilizes at a physical global mean steady-state temperature quite far below the hypothetical blackbody emission temperature corresponding to the averaged radiative heat balance (if the balance is an average 296 W/m2 IN, 296 W/m2 OUT, the ideal, evened out BB temp would be 269K, but due to large spatial and temporal swings in temperature, the actual mean will be lower, on Earth likely around 209K).
- A massive atmosphere is placed on top of the solar-heated surface. It starts holding surface heat back, spreading it from relatively hot areas to relatively cold ones, evening out the temperature amplitudes. This naturally raises the global mean. The thicker the atmosphere, the more the amplitudes are cut down. But by itself, this process could only ever raise the global mean as far as the ideal BB emission temperature corresponding to the particular planetary radiative balance. At this point, the global surface would be isothermal both in space and time. Mars is very far from this situation. Earth is quite far from it, but still much closer. Venus is pretty much there.
- The drawback (as seen from a surface perspective) of placing an atmosphere on top of a solar-heated planetary surface is that clouds and areosols and the air molecules themselves prevent parts of the incoming solar heat from ever making it to the ground, reducing its heating potential, by reflecting and scattering and absorbing significant parts of the solar radiation. The averaged 296 W/m2 no-atmo surface input (the lunar value) is reduced in this way, on Earth, to a mere 165 W/m2. That’s nearly an 80% cutback. Which means that the target for the atmospheric process of evening out the temperature amplitudes on our planet would be 232K rather than 269K.
- However, this is where the mass of the atmosphere comes into proper play. The surface becomes directly convectively coupled with the atmosphere, and immediately starts shedding some of its energy to it rather than to its ultimate heat sink, space, warming the atmosphere in the process. The surface heat thus being transferred to the massive atmosphere above piles up in the atmosphere (it is ‘trapped’, it never reaches space, but goes rather into accumulation, extending the quasi-surficial ‘internal energy’ storage of the planetary system, on Earth encompassing the land, ice and biosphere, the ocean, and the atmosphere) and distributes there in a very specific pattern, warmer down low, cooler up high, up to the point of thermal balance, a steady state where the energy and temperature distribution from the surface up to what is called the ‘tropopause’ is forced to settle around a gravity-constrained (pressure/density) gradient. In this state of dynamic equilibrium there is finally a mean balance being achieved between the heat coming in through the ToA and into the surface and the heat going out from the surface and out through the ToA. Any ‘new’ heat coming in from the Sun and going out from the surface after this stage is considered ‘surplus energy’ and needs to be shed from the Earth system as a whole to space. However, it will have to do so by first moving through the warm atmosphere, along the naturally set up temperature gradient. The surface excess energy is thus transported by convection from the heating end (the surface at the bottom) through to the cooling end (the tropopause at the top). In other words, the atmosphere acts like a ‘conductive’ insulating layer around the constantly solar-heated planetary surface, putting certain limits on the heat transfer rates away from the surface.
- The upward movement of air from the lowermost layer of the atmosphere, directly warmed from (and/or buoyed by) surface>air heat transfer, the de facto mechanism facilitating the effective cooling of a solar-heated surface under a massive atmosphere, is far from unrestricted in its operation at some particular temperature (kinetic level). It is limited mainly by three atmospheric mass properties: (1) the atmospheric temperature (gradient), (2) the atmospheric pressure, and (3) the degree of atmospheric ‘sluggishness’.
- (1) The gentler the tropospheric vertical temperature gradient, the slower the relative upward movement of air for a particular level of surface heating. In other words, the more the surface needs to warm in order to sufficiently increase the rate of convective heat transfer up and away from the surface (compare the balsa wood wall analogy). This is probably the more important temperature-raising factor on Mars (adiabatic lapse rate: 4.3 K/km; environmental lapse rate: 2.5 K/km).
- (2) The heavier the atmosphere, the greater the surface pressure and the harder water (H2O) would find it to evaporate from the surface of a planet at a particular temperature. In other words, the warmer a watery surface would need to be to sustain an adequate rate of evaporation, to balance a certain level of solar heat input. This is most likely the most important temperature-raising factor on a water world like Earth.
- (3) The thicker and heavier the atmosphere, the more sluggish it becomes, and the more resistant to change (non-responsive) – and hence, stable – it gets. Horizontal temperature/pressure differentials will be smaller, leading to slower and more steady wind regimes. At the same time, the air moving along the surface will tend towards more laminar and less turbulent flow, reducing the vertical component of surface air movement. Finally, the temporal (diurnal/seasonal) temperature/pressure differentials will be smaller, leading to more stable vertical gradients, a situation which in turn inhibits efficient convective uplift. This is most likely the most important temperature-raising factor on Venus, whose surface air is nearly isothermal in space and time, super-heavy and sludgy, almost non-responsive to external forcing, moving extremely slowly in a near-perfect laminar manner and with a highly stable lapse rate from the surface and several tens of kilometres up.
Finally, I will need one more post on this topic to address the obvious issue of radiation. Why doesn’t a planet’s own thermal radiation matter in the end when it comes to its mean steady-state surface temperature? Bottom line: It’s an effect, not a cause of the temperatures ultimately set by the other processes discussed in this post.
Okulær 
What do have to say about this:
Click to access Lunar_cooling_disproves_earth_greenhouse_effect.pdf
and this:
Why the Moon gets both Colder and Hotter than Earth — http://www.principia-scientific.org/why-the-moon-get-both-colder-and-hotter-than-eart.html (and also the back and forth in comments)
I will study you post and give it serious thought this weekend when time allows. Thanks for the write up.
~ Mark
Mark,
Thanks. The Moon gets both hotter and colder than Earth. This is obviously because the Moon 1) doesn’t have an ocean like we do, and 2) doesn’t have an atmosphere like we do.
You can read about the lunar (equatorial) diurnal temperature swings here: http://onlinelibrary.wiley.com/doi/10.1029/2011JE003987/full
It says: “The Moon’s highly insulating surface and slow rotation allow daytime temperatures to nearly equilibrate with the solar flux. Therefore daytime temperatures are influenced by topographic effects and radiative properties, but do not reveal much about bulk thermophysical properties. (…) Nighttime temperatures, however, are diagnostic of near-surface thermophysical properties. At night the surface radiates to space the energy stored in the regolith during the day. Because the near-surface regolith is highly insulating, heat exchange occurs only within the upper ~30 cm at the equator, and diffusion of energy is slow. Energy from progressively deeper levels is conducted toward the surface as the night progresses. Variations in thermophysical properties with depth will manifest themselves as variations in rate of energy radiated at the surface (i.e., changes in the slope of temperature versus time).”
Their figure 4:
http://onlinelibrary.wiley.com/store/10.1029/2011JE003987/asset/image_n/jgre3030-fig-0004.png?v=1&t=i9oauf35&s=11aa6d1972c2343487e3a026c276ee282ad684df
It is quite trivial to explain this diurnal curve (upper one), and the average temperature at the lunar equator is estimated to lie somewhere between 200 and 220 K. The global would clearly be lower …
okulaer says: May 14, 2015 at 3:08 pm
Mostly a parrot of what the CAGW alarmists spout.
This atmosphere is in no way an insulator. Although there is a delta T (lapse rate) none is required, this atmosphere is better at generating EMR exit flux than the surface can be! Not only that but this flux is adjustable via WV to result in a wide range of surface temperatures. If you cannot determine the cause of local relative humidity, temperature cannot be determined. Average temperature in any spatial/temporal sense has NO meaning. Remember to exit 240W/m^2 to space with no opposing radiance a “surface” “must” have a “minimum”: temperature of 255 Kelvin. Anything higher is fine depending on spectral emissivity.
Because of atmospheric vertical structure (mostly clouds) this atmosphere can exit the same 240W/m^2 at a minimum temperature of 215 Kelvin, into two PI steradians (outward with no opposing radiance). Is the aggregate of atmospheric spectral, and specular emissivity the same as the surface? YESS as far as anyone can measure!
Kindest regards 🙂 -will-
Hi Kristian,
First, I have been patiently waiting for you (and Rafael) to respond to my Eureka moment I described to you and readers of your post ‘The enhanced greenhouse’ in my response of March 23, 2015 at 3:48AM.
But specifically I write now relative to your statements: “The Moon gets both hotter and colder than Earth. This is obviously because the Moon 1) doesn’t have an ocean like we do, and 2) doesn’t have an atmosphere like we do.” When I read your posting I was tempted to review a critically important observed fact of the moon’s surface of which you have now acknowledged. The observed fact is the moon’s surface has (or is) a 1 to 2cm thermally insulating layer. But even though you acknowledge this fact, it seems you do not consider it a significant factor of the Moon’s surface extreme ‘diurnal’ temperature oscillation. At least, you did not list it as 3).
In my response to which I have just referred I described a modified Suomi, et al. net radiometer I had constructed to observe the downward radiation from the sky by observing the temperature of its absorbing-emitting (a-e) surface. By the radiometer’s design the a-e surface is thermally isolated from its environment by the mechanisms of conduction and convection, so the only thermal transfer mechanism is ideally radiation. Of course, practically such an ideal condition can never exist. But the fact I have observed a-e temperatures greater than 373K near midday near the summer solstice at 45N when the ambient temperature was no greater that 303K is observed evidence of the effectiveness of the designed isolation. And as I seem to remember, you recognized that one factor of the earth’s atmosphere was that it reduced the solar flux reaching the earth’s surface.
I draw attention to the radiometer because it a-e surface has a very limited thermal inertia. Hence, once solar radiation becomes the dominant radiation warming the a-e surface, the temperature increase-decrease during this daytime period is similar to that of the moon during its ‘daytime’ period. With the exception, that near sunrise and sunset, the downward LWIR radiation from the sky becomes the dominant radiation maintaining (warming) the a-e surface.
And this LWIR downward radiation from the sky has some relationship to the upward LWIR being emitted by the earth’s surface, whether it be ocean, land, or ice. These three possible sources of LWIR have significant thermal inertias relative to the a-e surface or the insulating surface of the moon. Except for freshly fallen snow which can be the best earth based insulator because of its very low density, but it can never be better than that of air. While I have never read of the insulating capability of the lunar insulating surface, I can imagine it could be better than air plus the fact that it might not transmit either solar radiation or LWIR radiation.
Just looked at that the article to which you referred and I see they propose that radiation between particles becomes a heat transfer mechanism in the upper portion of the insulating layer. I also find that they give figures of a single diurnal cycle so certain details may be better seen. The important issue I want to emphasize is that the temperature peaks at midday. Therefore, there is no evidence of any significant thermal inertia, but obviously some storage of sensible heat because there is evidence of some cooling during the nighttime. But the forced conclusion there is very little storage of sensible heat during daytime because most all the solar radiation absorbed at the surface is immediately emitted as LWIR radiation from surface at near maximum theoretically possible temperatures. Hence, the article’s concern about the albedo of the surface.
I almost made a mistake that I fault others of making. Which is proposing an impossible scenario which can never be observed. I had started proposing what might be the result if the moon had an atmosphere. But I believe it is a fact that the moon does not (cannot) have an atmosphere because its gravity is not sufficient to retain an atmosphere at the expected temperatures of its surface.
So, relative to the Moon gets both hotter and colder than Earth, I would state this is obviously because the Moon 1) doesn’t have an ocean like we do, but 2) has a thin, insulating, surface layer which the Earth doesn’t have.
Have a good day, Jerry
jerry l krause says: May 18, 2015 at 1:25 pm
“I described a modified Suomi, et al. net radiometer I had constructed to observe the downward radiation from the sky by observing the temperature of its absorbing-emitting (a-e) surface. By the radiometer’s design the a-e surface is thermally isolated from its environment by the mechanisms of conduction and convection, so the only thermal transfer mechanism is ideally radiation.”
Dr. Krause,
I left a message on the PSI site about your questions.
In your description of your radiometer you describe an outer polyethylene film, and you refer to temperature.
Is this “film” in addition to a rigid window?
What are the transmission characteristics of that filter?
Is the sensor in an evacuated chamber?
What stops conductive heat transfer?
A radiometer measures only “radiance”, how was Kelvin determined?
As i read Okulaer, he says mainly that the atmosphere act as a heat distributor and a cooling agent. I look forward to his last post on the topic, because that will most probably fill inn the missing links on radiation. Or maybe I should say the last two posts, because there is a strong need for a “Summary for policymakers” 😉
Hi Will,
I have only been responding to blogs for a year or so and not familiar with what the PSI site might be. I have read many of your responses to Kristian and others so I am somewhat familiar with you. The radiometer to which I refer is one-half of the net radiometer described in this article. V. E. Suomi, D. O. Staley, and P. M. Kuhn, “a Direct Measurement of Infra-red Radiation Divergence to 160mb,” Quarterly Journal of the Royal Meteorological Society, vol. 84, No. 360, Apr. 1958, pp. 134-141. In this article they evaluate the technical issues about which you ask. And I trust V. E. Suomi’s evaluation of this very simple, inexpensive, radiometer.
But this is my description of the construction of the radiometer I use which I wrote JohnKl (Spencer’s website). I have made several radiometers trying to find the best and easiest construction. The basic problem was how to hold the polyethylene film (economy plastic wrap at Walmart according to their website) reasonably taut (does not seem to need be anywhere close to perfect), how to cut uniform circular holes in the squares, and how to simply hold the five 8in by 8in squares of 1/2in extruded Styrofoam together.
Since I had never actually done what I planned to propose I concluded I needed to do a test run. I bought the Styrofoam at either Home Depot or Lowes and they did have sheets smaller than the standard 4ft by 8ft sheets but the smaller cost nearly as much as the larger so I got the larger. With even a 2ft by 4ft sheet you can make three radiometers. I read that the extruded Styrofoam will absorb water so my sheet had some rather heavy film (I assume waterproof) on both sides which requires a sharp utility knife, after my trail run I recommend a narrow one which has the blade sectioned so the end can be broken off as it dulls. The narrow is important as you cut out the circular holes.
You cut 4in diameter holes, centered as precisely as possible (just looks a little more professional) on the square, in three of the squares. A 4in diameter coffee can, lightly tapped, defines the hole. Then you use the utility knife to cut the hole. I recommend first lightly cutting the film and the second time around cutting as vertically as possible the Styrofoam with cardboard beneath it. Then there should be indents on the bottom side to follow as you cut the film on this side.
Then with two of the squares with 4in diameter holes mark a 6in diameter concentric circle with a 6in diameter coffee can. This creates a ring to hold the film in place. Cut the ring as before but do not remove ring until marking ring and square two places (not directly across from each other) so you can, after spreading the film across the square, replace the ring as it was before.
Cut a 5in by 5in square of aluminum foil and spray it with common, flat, black paint. It will be the absorbing-emitting surface and will be place over the 4in diameter hole in the third square. But before placing it there, I recommend that you poke your food temperature probe (I started with dial probes but the uncertainty of reading the temperature caused me to switch to a digital probe. I am using a Tru Temp -40/302oF probe which was available at Target) through the 1in wall of the square into the hole as level, and centered, as possible so it will not touch either a-e surface of the solid square beneath it. Harbor Freight has a cheaper digital but its probe is a slightly large diameter necessitating the possible need to drill a hole for it and is cheaper quality wise. Battery contact problems.
So assemble by starting with the two solid, insulting, squares, next square with a-e surface up, next square with film up, and finally square with film up. Align holes as best possible. Now, using 2.5in sheetrock screws, screw each corner a little to the side of the diagonal. Turn over and screw each corner a little to the other side of the diagonal.
If a film gets punctured or you do not like the moisture which can get inside during rain or heavy dew, the screws make it easy to disassemble and correct the problem. The sixth square make a nice cover to protect the films when not in use.
Suomi, Staley, and Kuhn extensively evaluated their net radiometer. One limitation of which I am aware is that the 1in wall of the insulating cylinders casts shadows when viewing the direct sun and creates a ‘cone’ of the detection of diffuse radiation. But this seems to possibly be a potential problem. This might be a topic for later consideration.
The critical utility of this radiometer is that it does not directly output “radiance”. That has to be calculated from the directly observed temperature of its a-e surface. Which is electronically done with any radiometer which directly outputs radiance. And therefore, the radiance to which you, Kristian, and everybody else refers, is never translated back to the actual temperature of the radiating surface. Hence, given this general practice, no one can have had the Eureka moment to which I referred.
I have no idea if you have previously read any of my previous responses. So, I will summarize my theme (for lack of better word). I am very critical of the all debate I read. I am very critical of the averaging process being used which immediately destroys information. And I find that once I refer to reproducible observations, there are few, if any, responses as documented by the fact that Kristian and Rafael have not yet responded to my Eureka moment reported to them nearly two months ago.
I very much appreciate the fact that you have inquired about the SSK radiometer, which I consider to be a very fundamental instrument with which to observe our radiative atmospheric system. Second, only to the thermometer. I am very curious of what your response to this might be.
Have a good day, Jerry
jerry l krause says:
May 20, 2015 at 4:40 pm
Hi Will,
“I have no idea if you have previously read any of my previous responses. So, I will summarize my theme (for lack of better word). I am very critical of the all debate I read. I am very critical of the averaging process being used which immediately destroys information. And I find that once I refer to reproducible observations, there are few, if any, responses as documented by the fact that Kristian and Rafael have not yet responded to my Eureka moment reported to them nearly two months ago.”
Thank you for your kind reply!
I have read all comments ‘The enhanced greenhouse’ thread here!
PSI is http://www.principia-scientific.org/why-the-moon-get-both-colder-and-hotter-than-eart.html#comment-11094
This is where Kristian was posting on 5/15.
Kristian also posted today at Tallbloke’s Talkshop.
“I very much appreciate the fact that you have inquired about the SSK radiometer, which I consider to be a very fundamental instrument with which to observe our radiative atmospheric system. Second, only to the thermometer. I am very curious of what your response to this might be.”
I downloaded the paper You suggested. It has no description of the instrument itself. Let me guess:
Two separated black aluminium foil plates, with further separated thin poly windows. One window facing insolation, the other facing Earth’s surface. Your only measurement is the temperature of isolated air between the two foils! If that is not correct please a bit more info.
Response:
That device will be sensitive to both insolation increasing temperature and to 8-14 micron flux to the surface, decreasing temperature, “but” only if the lower foil is at some higher temperature than the surface.
The problem I see is that all other forms of heat transfer also affect that temperature! It is hard to discern what your temperature may mean! That does not mean you should stop measuring! When measuring, write down all else that might have changed from measurement to measurement.
Several times it took years to figure what my measurement may mean. That of course is much better than deriving some fantasy of what is! Please do not let anyone change your written numbers. What you have are absolutely the the “best” measurement at that place and time, of whatever you were measuring.
A few more questions please:
You mentioned dew on the poly window, when was that?
Can you think of any method beside some forms of EMR that can raise the temperature of “else”, above it own?
Why do you claim that EMR based only on temperature can do any better?
Please comment on:
http://www.hukseflux.com/product_group/heat-flux-sensors
All the best -will-
Hi Will,
Just reread your and others comments of Kristian’s Feb 19 post about the ills of today’s science. I did note that you were promoting measurement (observation) which I maybe missed the first time I read it. What it seems you all do not know is model of science which Galileo and then Newton gave us by writing their classic books. I know all during my formal science education it was never suggested that I might read them and I never suggested that my students should until very near the end of my teaching career.
At that time chemistry professors and instructors were recognizing we were failing our students. Professor Orville L. Chapman courageously spoke at a workshop, titled Innovation and Change in the Chemistry Curriculum sponsored by NSF in 1992. He stated: “Is our structure sound? If it is, why can we not expand our clientele? We ignore the education of all our students but especially those who choose not to take a chemistry course. Our current students leave our courses as scientifically illiterate as when they entered.”
About this time I obtained copies of Galileo’s and Newton’s books and found portions of both easily readable. At this time community colleges system in Minnesota obtained a NSF study grant to identify at risk science students and to develop some courses to prepare such students for our courses. In our region, this project was headed by an English instructor. Who decided the course I proposed using Galileo’s book as a reference, was a graduate level course and I was removed from the project. At this time I discovered the physicist of a nearby community college did not consider himself a scientist. He was a science educator. Because of this, at a state staff development activity for community college chemistry instructors, a poll showed that only half of this group considered themselves to be scientists. Which clearly surprised those who considered themselves to be scientists.
Galileo refuted three fundamental ideas which had existed for nearly 2000 years with simple demonstrations (observations). As I read your debates (attempts to educate each other) I doubt that any of you are aware how simple it can be to refute wrong ideas by demonstration (observation). And the leader of this group is Roy Spencer. I began to participate on his blogsite to draw two facts to his attention and I succeed in this effort. The first commonly known fact was that the atmospheric temperature has never been observed to be lower than the atmosphere’s dewpoint temperature. To which he agreed and then stated that he could not see my point.
And he documented that he did not see my point by proposing his scenario of a moist soil being with a temperature near 80F that did not freeze before morning. And the explanation he gave for its failure to freeze. Dewpoint temperature was referred to 39 times in the 1546 comments which Roy’s post generated. Most, were by myself. But Menicholas and Rich Lentz independently referred to their common everyday experiences associated with the formation of dew or frost.
But Roy proposed the explanation for the lack of freezing during the night was because of the greenhouse effect. While the atmosphere’s dewpoint temperature does not always limit the minimum diurnal temperature, it often does. I have no doubt that when it does, it is positive evidence that there is no greenhouse effect. And in this post of Roy several pointed out that the temperature might drop to freezing if the soil was dry enough that the thermal inertia of the soil would be the limiting factor that the minimum temperature did not fall to the atmosphere’s dewpoint.
These common observations are positive evidence that the greenhouse effect is not limiting the minimum temperature of a day.
In searching for the occurences of dewpoint temperatures, I discovered a comment of Joel Shore addressed to something I had written. He wrote: “All models of the greenhouse effect have an atmosphere colder than the surface.” And it seems the arguments about the 2nd Law are based on this assumption which have been commonly observed to be not true. For the longest time I was not aware that I could access atmospheric sounding data. And I was curious of what the temperature inversion that commonly forms during the night looked like. It seems that the modeler of the greenhouse effect and those which argue the 2nd Law have never seen a common temperature inversion.
Nor have these people thought about what cools first if a common temperature inversion forms. Or about the significant difference between condensed matter (solid or liquid) and gases. The earth surface is heated by the solar insolation and it in turn generally heats the colder atmosphere in contact with it. But there is evidence that the IR portion of solar insolation does first heat the atmosphere a slight amount before the same solar insolation begins to heat the surface. But when the atmosphere begins cool in the afternoon, it is because the solar insolation is not sufficient to prevent the surface from beginning to cool. So the fact is from this time to the next morning the surface is cooler than a portion of the atmosphere above.
If you study this situation you must come to the conclusion that the condensed surface is a more ‘effective’ radiator than the atmosphere over it. And you must come to the conclusion that the surface emission through the atmosphere is not warming the atmosphere directly above it. The fact that the peak temperature of the temperature inversion that forms during the night is usually a 1000 feet or more above the surface (air is a poor thermal conductor and the temperature inversion eliminates any convection), forces the conclusion the atmosphere is being cooled by radiation to the colder surface which absorbs the radiation and effectively emits it through the warmer atmosphere which cannot absorb this radiation from the colder surface.
Bet you haven’t read this bit of imagination before.
Have a good day, Jerry
Hi Will,
You asked me to comment as above. At least I hope this comment will follow yours. Have you received them? For I attempted to answer the temperature question which you just stated I had not addressed. I have a better answer which I will send to the above.
Have a good day, Jerry
jerry l krause says: May 22, 2015 at 2:52 am
“Hi Will, As I read your debates (attempts to educate each other) I doubt that any of you are aware how simple it can be to refute wrong ideas by demonstration (observation). And the leader of this group is Roy Spencer.”
Jerry,
Spencer and Willis E. do only thought problems never any demonstration. They certainly cannot demonstrate thermal EMR flux emitting in opposing directions. They both insist that it does. questions
“I began to participate on his blogsite to draw two facts to his attention and I succeed in this effort. The first commonly known fact was that the atmospheric temperature has never been observed to be lower than the atmosphere’s dewpoint temperature. To which he agreed and then stated that he could not see my point.”
I can’t see your point either. The dew point temperature is only a measure of the water vapour content of the air. As the WV condenses the dew point (frost point) can drop to -30 Celsius. What is your point?
Other unanswered questions:
1) Can you think of any method beside some forms of EMR that can raise the temperature of “else”, above it own?
2) Why do you claim that EMR based only on temperature can do any better?
Hi Will,
Thank you for your response. I have not responded to: Can you think of any method beside some forms of EMR that can raise the temperature of “else”, above it own? This because I do not really grasp what “else” is and to what ‘above it own’ is referring. So I have to do some assuming. Maybe, else is the air beneath the a-e surface whose temperature I am assuming to be that of the a-e surface. Next, because you refer to the raising of temperature, I assume you are referring the heating of the a-e surface by solar isolation.
Toward the end of the responses to Spencer’s post of Apr 15 (Winter returns), I report the result of placing a glass sheet on the radiometer. I did this because Tim Folkerts had stated the glass would transmit the ingoing solar insolation and absorb the outgoing LWIR radiation. I know that this was the origin of the greenhouse effect so I was curious of what would actually occur. The temperature of the a-e surface increased. And the glass sheet was clearly warmed by absorbing a portion of the outgoing LWIR radiation from the radiometer. And as I tried to analysis what was occurring I ended up with a paradox to which I do not know an answer. I have no idea if this is an answer to your question.
While I had sent you to what I assume is your place of employment, a response to the question about my claimed importance of temperature, I had just completed a better (more complete) response to this question. I am waiting on submitting it until you confirm where you prefer it to be submitted.
But I am very intrigued by the fact you, like Spencer, cannot see (understand) what the point of the dewpoint temperature is. Spencer seldom enters into an extended dialogue so I could never learn what his, or my problem, was. But with you I have a chance because we have dialogued.
It seems a fact that many beside you and Spencer do not see my point. And I need to find out what the problem is. You wrote: “I can’t see your point either. The dew point temperature is only a measure of the water vapor content of the air. As the WV condenses the dew point (frost point) can drop to -30 Celsius. What is your point?
I asked myself: Why did Will comment: “As the WV condenses the dew point (frost point) can drop to -30 Celsius.”? Where did he learn that condensation could seemingly, quickly, reduce the vapor content of the air? Which is what his comment seems to suggest can happen. I quickly saw such is part of the model of the vertical convection whose result is common, brief, thunderstorm. At this point I reviewed what popular USA meteorology textbooks had to say about dewpoint temperature and thunderstorms. There I quickly discovered the answer was not much beyond the definition of dew point temperature stated by Will (you).
Because I accept the truth of Galileo’s statement: “We cannot teach people anything; we can only help them discover it within themselves.” I ask the question: What happens as the WV condenses?
Have a good day, Jerry
jerry l krause says: May 23, 2015 at 3:42 am
“Hi Will , Thank you for your response. I have not responded to: Can you think of any method beside some forms of EMR that can raise the temperature of “else”, above it own?
This because I do not really grasp what “else” is and to what ‘above it own’ is referring. So I have to do some assuming.”
Not at all, you must communicate your competence in any subject, even if it is none. You have written of chemistry. From your reply above you demonstrate no understanding of any of the hard sciences including philosophy. Please state your CV and experience, other than teaching innocents the lies of others, from some textbook?
In engineering and philosophy “self or own” is extremely local as opposed to “else or other”. Else or other is “all” that is non local. Self mass can have temperature (sensible heat), other else mass can have different temperature (sensible heat). Such heat (energy) may be spontaneously transferred only from some mass at higher temperature to some mass at lower temperature. Such energy transfer must lower the temperature of self mass while increasing the temperature of else mass. This is 700 years of observation, with no falsification, and makes this the second law of thermodynamics.
“Can you think of any method beside some forms of EMR that can raise the temperature of “else”, above its own?”
All the best -will-
Hi Will,
Just because I did not give an acceptable answer to your questions, I did give my answers. Now be a gentleman and answer: What happens as the WV condenses?
Have a good day, Jerry
jerry l krause says:
May 23, 2015 at 10:58 pm
” Hi Will, Just because I did not give an acceptable answer to your questions, I did give my answers. Now be a gentleman and answer: What happens as the WV condenses? Have a good day, Jerry
As far as anyone knows That latent heat (entropy of evaporation)
Is converted to any other form of energy as the H2O volume shrinks to a value of 10^-5. Some converts to sensible heat (temperature), Most simply powers the EMR flux to space, with no change in temperature.
Most of the WV converts to Water condensate, still supported as an aerosol by hydrodynamic forces.
87% of the atmospheric column water never becomes precipitate to the surface. It floats in the atmosphere converting from condensate to WV sunside.Then converting back to condensate darkside. This releases 2400 Joules per gram of WV conversion as EMR to space each day!!!.
My questions are specifically two:
1) Can you think of any method beside some forms of EMR that can raise the temperature of “else”, above its “own”?
2) Why do you claim that EMR based only on temperature can do any better?
I am not looking for the 97% answer! I am looking for “your” answer!
Guesses are fine! This promotes understanding in dialog! -will-.
Hi Will,
Dialect, n, A local or provincial form of a language, differing from other forms, esp. from the standard or literary form. Dialectic, n, That branch of logic which teaches the art of disputation and of discriminating truth from error; esp., the art of reasoning about matters of opinion. (Webster’s New Collegiate Dictionary) “intuitive knowledge keeps pace with accurate definition.” (Elzevirs, publishers of Dialogues Concerning Two New Sciences)
In matters of Natural Philosophy Galileo demonstrated that thousands of years of disputation failed to find what can be seen by simple observation. I admit that it took me several years to comprehend this common saying of that time which I had never encountered before. From the beginning a question was: accurate definition of what? Words? Slowly, I have become quite certain the accurate definition ultimately refers to the specific natural system (phenomenon) being studied.
Roy Spencer agreed that it is an observed fact to this point in time that the temperature of a specific element of atmosphere could never be below the dewpoint temperature of that specific element of atmosphere. However, Roy then stated he could not see what my point might be. Then, you state that you too cannot see my point. So, it seems both of you cannot not see what this might have to do with the hypothesis commonly known of the greenhouse effect. I had added—which you both seem to accept as a valid hypothesis—but as I considered this I must admit that I do not know your position on this issue.
Part of the problem is that the greenhouse effect, as a hypothesis, has not been specifically, accurately, defined. I have noted the fact, time again, that Verner Suomi is said to have stated that the observation of downward LWIR radiation from a clear sky during the nighttime is positive evidence of the greenhouse effect. Since I do not observe the temperature of the radiometer’s a-e surface, which I use to observe the presence of this downward radiation, dropping to near absolute zero, I accept that there is positive evidence the existence of downward radiation from a clear sky during the nighttime. But, I know the presence of this downward radiation is not what is controversial about this hypothesis. The controversy is about the proposed result of this downward LWIR radiation relative to the atmosphere’s temperature as commonly observed (in a specifically defined way) about 1.5m above the earth’s surface. A proposed result of this downward radiation, that seems widely accepted by the proponents of the greenhouse effect, is that that the average temperature of the earth’s atmosphere would be about 33 degrees Celsius less than it is observed to be if not for this downward radiation.
Recently (April 10), you know Spencer posted Why Summer Nighttime Temperatures Don’t Fall Below Freezing. I review a portion of it here so you do not need to jump back and forth. It began: “There’s something about the greenhouse effect /sky radiation / downwelling infrared / back radiation issue that keeps drawing me back to the subject.
“I guess it’s the number of people who don’t believe the so-called greenhouse effect exists (I still get e-mails from them, even today), combined with the difficulty of convincing them that their everyday experience is consistent with its existence.
”So, just for laughs, here’s another demonstration, involving a simple model of the cooling of the soil at night.
“At night the soil cools by loss of infrared radiation. The Stefan-Boltzmann equation lets us estimate the rate at which IR energy is being lost based upon surface temperature and emissivity, and simply dividing that by the product of the soil depth and soil bulk heat capacity gives us the rate at which the soil layer temperature will fall. Basic physics and thermodynamics.
“From that we can make a simple time-dependent model to calculate the change in temperature throughout the night. This simple spreadsheet model I’ve provided here will allow you to change assumed parameters to see how to get a realistic temperature decline over 12 nighttime hours. What you will find is that the temperature falls to unrealistically cold levels unless you assume a large downwelling energy flux from the sky into the soil (also adjustable in the model).
“If you are wondering, “what about cooling of the atmosphere in contact with the ground?”, well just make the soil layer deeper…it turns out that 0.2 meters of soil is equivalent in bulk heat capacity to about 200 m of atmosphere.
“The adjustable parameters (in red in the spreadsheet) are soil depth (0.2 m is typical for day-night temperature changes), the soil heat capacity (2.5 is typical, water is 4.18), the IR emissivity (0.90-0.95 would be typical), the downwelling sky radiation intensity (0 for all you sky dragon slayers [SDSs] out there, 250-350 for the rest of us), and the starting temperature (300 K is about 80 deg. F).
“For example, for a 0.2 m moist soil layer (about 8 inches thick), starting at 80 deg. F, the rate of energy loss over 12 hours is enough to cool that soil layer down to 25 deg. F….IF you don’t assume any downwelling IR from the sky (the SDS-recommended setting):
“But, if you assume the Trenberthian global-average value of 330 W/m2 for downwelling sky radiation, the soil cools from 80 to about 67 deg. F, a much more realistic value:
“Now, as I’ve mentioned before, as much as 75% of this big, bad greenhouse effect is “short-circuited” by convective heat loss by the surface, which is almost entirely a daytime phenomenon over land (nighttime surface temperatures quickly cool the near-surface air to make it convectively stable).”
In quoting Spencer I have not included the figures he used to augment his words. But I have not omitted any words from the scenario he defined to illustrate an everyday experience which he contents is consistent with the existence of the greenhouse effect. I agree totally with two related statements: “At night the soil cools by loss of infrared radiation.” and “nighttime surface temperatures quickly cool the near-surface air to make it convectively stable.” To me they are critically important because they are an essential component of accurate definition of the scenario he proposes. And the second calls attention to the fact that the atmosphere is factor of the scenario he proposes even though he tried to eliminate the atmosphere with the statement: “If you are wondering, “what about cooling of the atmosphere in contact with the ground?”, well just make the soil layer deeper…it turns out that 0.2 meters of soil is equivalent in bulk heat capacity to about 200 m of atmosphere.”
While I cannot reference the post where Roy stated that ground based meteorological observations were next to worthless, if not worthless, I know I read such. And he stated the reason for this opinion was that satellite based observation were far superior. Spoken like a good NASA employee. I have often encouraged others to study the historical weather records for the nearest airport to whatever location on the earth which can be accessed at wunderground.com. The headings of twelve columns are: Time, Temp, Dew Point, Humidity, Pressure, Visibility, Wind Dir, Wind Speed, Gust Speed, Precip, Events, Conditions. These are the eleven components (factors, whatever) that someone has decided are necessary to accurately define the atmosphere every hour, if not more often. Most headings need no definition. But the last three might. Precip is the amount of precipitation that has been measured since the previous record. Events is the precipitation event occurring at the time including fog. Conditions is the condition of the atmosphere (sky): clear, partly cloudy, mostly cloudy, overcast.
Spencer’s proposed scenario has no meaning if the conditions are not clear. Hence, he did not begin to accurately define the conditions of his scenario. His focus is upon the cooling of an 8in thick, moist, soil layer during a midsummer’s nighttime. Yet, his proposed 12hr nighttime suggests it might be nearer an equinox than to the summer solstice or nearer to the equator than at a higher latitude where there are more usually clearly defined seasons. This is positive evidence that Spencer does not take great care to accurate define; so relative to his scenario there is a clear lack of accurate definition. Hence, there can be no intuitive knowledge gained by a consideration of his proposed scenario.
According to the information supplied on his site, he lives near Huntsville AL. The airport nearest to Huntsville did not record the hourly observations during the entire day until 2015. From sunset of May 10, 2015 to sunrise of May 11, a period of a little more than 10hrs, the sky was reported to be clear. Temperatures reported are degrees Fahrenheit. The hour before sunset the temperature was 82.9 and the dew point was 65.3. The hour after sunset the temperature was 80.2 and the dew point was 65.1. The hour before sunrise the temperature was 69.6 and the dew point was 65.3. The hour after sunrise the temperature was 67.6, the minimum temperature of the 11th, and the dew point was 65.1. Be reminded that these temperatures are the atmosphere about 1.5m above the surface being observed in a ventilated enclosure to the temperature sensor can never to exposed to direct solar radiation. Hence, this prevents the sensor from being exposed to the clear sky. Spencer’s temperatures were of the soil surface exposed to the open sky. Of course, his temperatures were never measured, they were just thought.
Since you know there is a latent heat associated with WV condensation, you decide if the low temperature of the morning is due to the greenhouse effect as stated (proposed would be too weak a word) by Spencer or due to the fact that the atmospheric temperature can never cool below its dew point.
Have a good day, Jerry
Hi Will,
As I have said, I am not sharp. And I have less directly acknowledged that I do not have a good memory. Relative to my previous post, this morning I realized I had not cited the most critical ground based observation because it is never part of the weather record. It is the observation of the formation of dew during such a clear night given the moist soil condition.
But it took me a little while longer to realize that Spencer’s thought experiment was a rational being used to support the idea of the greenhouse effect forty years ago in textbooks and news articles. Which was the reference to warm summer nights in Iowa which were known then to contribute to the great yields of corn being grown in Iowa. Which, because I grew up on a farm where the soil was not consistently as moist and therefore our nights were consistently not as warm, I knew was not due to any greenhouse effect but due to the formation of dew during the night. Sometime during the past year or two, I had reviewed this fact and how this ‘example’ of the greenhouse effect had disappeared from the textbooks.
However, until this morning, I did not recognize Spencer’s post— Why Summer Nighttime Temperatures Don’t Fall Below Freezing—was merely a rerun of the old example which had disappeared from the textbooks. Because Spencer has done this I do not call him a liar nor do I call the textbook authors of forty years ago liars. They were overlooking something quite obvious, just I had in what I wrote yesterday.
Have a good day, Jerry
I now know why Kristain will no longer have a dialogue with you!!
Hi Will,
If you now know why Kristian will no longer have a dialogue with me, why don’t you accurately define what this reason is so I do not have to guess (assume) what this reason might be?
Have a good day, Jerry
I will try one more time. You seem to refuse to even consider the opinion of any that disagree with your fantasy. I have carefully explained “why” I agree with Dr.Spencer, on your Eureka moment, of dew-point, but you refuse to read and consider anything except your fantasy!
Hi Will,
Thank you for responding, even if you have not done what I asked.
You wrote: “I will try one more time. You seem to refuse to even consider the opinion of any that disagree with your fantasy. I have carefully explained “why” I agree with Dr. Spencer, on your Eureka moment, of dew-point, but you refuse to read and consider anything except your fantasy!”
The science I try to practice is based upon observation. You call observation fantasy. What is the basis of your ‘science’?
If I refuse to read, how is it that I found the words: dialect and dialectic and Roger Bacon, the 13th Century philosopher? For you are correct, I know little to nothing about philosophy and logic except that evidently it does not work in finding physical truths (Laws) because if it did, Galileo would have had nothing new to discover by actual experimentation and observation.
Have a good day, Jerry
Hi Will,
You wrote: “I will try one more time. You seem to refuse to even consider the opinion of any that disagree with your fantasy.”
I urge you to go the wunderground.com and look at the historical weather record for Brussels. It will be that observed at the airport identified as EBBR. Look at the monthly record and the Weather History Graph for the temperature and dew point. Then tell me again that these observations are my fantasy.
Have a good day, Jerry
Hi Will,
I do not know if you will read this, but it does not matter. I have thanked everyone with whom I have had a dialogue for responding to what I write for at least a little while. For I write to see what I might know and writing to someone who might be interested, especially if critically interested, in what I write gives me more incentive to write than merely to write to myself.
This will be about what Spencer got right, my judgment; fantasy, the 2nd Law, etc. I looked up the definition of fantasy: a product of imagination. Einstein is said to have stated: “The true sign of intelligence is not knowledge but imagination. Imagination is more important than knowledge.”
Feynman began his lectures to Caltech physics students: “If, in some cataclysm, all of scientific knowledge were to be destroyed, and one sentence passed on to the next generations of creatures, what statement would contain the most information in the fewest words? I believe it is the atomic hypothesis (or the atomic fact, or whatever you wish to call it) that all things are made of atoms—little particles that move around in perpetual motion, attracting each other when they are a little distance apart, but repelling upon being squeezed into one another. In that one sentence, you will see, there is an enormous amount of information about the world, if just a little imagination and thinking are applied.”
Why the importance of Feynman’s single sentence? I conclude it is that all this information cannot be directly seen (observed), it must be imagined and what needs to be imagined is not real logical. For John Dalton proposed his atomic hypothesis, 165 years after Galileo’s book was published, to explain an accepted scientific law, The Law of Constant (Definite) Composition, which had been established by quantitative experimental (observations) by that time. And the idea of perpetual motion, etc. became established at an even later time.
Spencer wrote: “At night the soil cools by loss of infrared radiation.” This is very a critical statement which I accept as being observed fact. For I have spoken to an atmospheric science professor who claimed the surface (soil) was cooled by the atmospheric layer in contact with it and it was this atmospheric layer which was being cooled by the loss of infrared radiation. Hence, the temperature of the soil (surface) was not a factor in the loss of infrared radiation. What could I say to this professor except state my doubt?
Spencer’s statement is where any understanding of the cooling of the atmosphere must begin. For, Spencer makes a second very critical statement: “over land (nighttime surface temperatures quickly cool the near-surface air to make it convectively stable).” For this near-surface air can be cooled by air conduction as well as radiation as the always cooler surface cools the atmosphere just above it. But I think (but do not know) you can accept that this conduction heat transfer mechanism is only active in a very shallow layer of the atmosphere because air, without the possibility of convection, is a quite good thermal insulator. And I hope you can accept that once temperature of the surface begins cooling by loss of infrared radiation, that the temperature of the surface is always less than the temperature of this shallow layer of atmosphere in contact with the surface. This is agreement is critical for this is where imagination must begin and thinking must begin.
Before I begin, it need be stated that every statement before and to follow is based on the assumption that the sky (atmosphere) is cloudless.
Accurate definition: We have two forms of matter (solid and gas) in contact with each other. We could reason there are only three possibilities. The solid cools by radiation more rapidly than the gas does, the gas cools by radiation more rapidly than the solid does, or they both cool by radiation at the same rate. I choose the first. The atmospheric scientists evidently chooses the second. You choose???
But I am the one who is writing this. The observed fact that the soil cools proves that there is no greenhouse effect which prevents the surface from cooling by radiation. But if the surface temperature is less than the temperature of the atmosphere, by the 2nd Law this radiation, which must pass through the atmosphere, cannot ‘warm’ the atmosphere whose temperature is greater than the surface. And because the surface is observed to cool, we know that its radiation must be eventually transmitted to space. Seldom is acknowledged, or considered, how rapidly, this radiation which is transmitted to space, must be transmitted to space. Which I reason is likely near the speed of light.
Now, I insert a bit of my fantasy (imagination). The rate of the greenhouse gases emission is not the result of the fact that these molecules are capable of absorbing certain infrared radiation, it should be the result of the temperature of their environment which is defined by the perpetual motion of all the molecules and atoms in a specific volume of space. And the relationship between temperature and this perpetual motion is explained by the kinetic molecular theory of gases as generally accepted. What I imagine is there must be some radiation law based upon atmospheric temperature for gases (diffuse matter) just as there is the S-B Law for condensed matter (solids and liquids). But this law for gases need not be the same as that for condensed matter because there are some very significant difference between gases (diffuse matter) and solids and liquids (condensed matter). But if the soil cools the atmosphere in contact with it, I must conclude that the rate of emission is greater for the soil than for the atmosphere at the same temperature, or even greater temperatures.
Spencer acknowledges the temperature structure of the shallow atmospheric layer in contact with the cooling surface is changed as the surface cools so that this layer becomes convectively stable. Which I understand means a temperature inversion is formed. The temperature gradient (change of temperature with altitude) of a convectively unstable requires that the temperature decrease with increasing altitude, hence a temperature inversion is when the temperature increases with increasing altitude.
Numerous times I have urged others to go to the University of Wyoming where one can access that the data of observations made during atmospheric soundings which are made various, worldwide, locations at the same time every 12hrs. It just happens that the city in which I live is one of these locations. And it just happens that these soundings here are launched at 4am and 4pm standard local time. This is fortunate for me because 4pm is near the time of the maximum atmosphere temperature observed at the time of the launch. And 4am is near enough to sunrise so that a majority of the nighttime cooling has already occurred. Hence, given the clear sky condition, temperature inversion are consistently observed to have formed to altitudes of more than a 1000ft (305m) above the surface. And temperatures of the atmosphere above this altitude of maximum temperature can remain greater than the atmosphere temperature commonly observed 1.5m above the surface at altitudes of 5000ft (1.5km) above the surface.
From what has been observed and stated, I must conclude that during the nighttime to the time of the sounding, the surface has cooled the atmosphere by absorbing its downward emission from that portion of the atmosphere whose temperature was greater than the surface temperature at a given time and was at the time of the sounding still capable of absorbing the downward emission from the warmer atmosphere (2nd Law) up to an attitude of 5000ft and emitting this infrared radiation as a portion of its radiation being transmitted to space through the atmosphere which contains greenhouse molecules.
The observations are not fantasy. My reasoning (thinking) based upon them and accepted scientific laws is fantasy.
Thank you for reading this. I imagine if you read this you have what preceded it.
Have a good day, Jerry