Guest Post by Ira Glickstein
Solar “light” radiation in = Earth “heat” radiation to Space out! That’s old news to those of us who understand all energy is fungible (may be converted to different forms of energy) and energy/mass is conserved (cannot be created nor destroyed).
My Visualizing series [Physical Analogy, Atmospheric Windows, Emission Spectra, and Molecules/Photons] has garnered almost 2000 comments, mostly positive. I’ve learned a lot from WUWT readers who know more than I do. However, some commenters seem to have been taken in by scientific-sounding objections to the basic science behind the Atmospheric “Greenhouse Effect”. Their objections seemed to add more heat than light to the discussion. This posting is designed to get back to basics and perhaps transform our heated arguments into more enlightened understanding :^)
As I’ve mentioned before, during my long career as a system engineer I’ve worked with many talented mathematical analysts who always provided precise results, mostly correct, but some precisely wrong, usually due to mistaken assumptions. I got into the habit of doing a “back of the envelope” calculation of my own as a “sanity check” on their results. If their results matched within reasonable limits, I accepted them. If not, I investigated further. In those days my analysis was really done using a slide rule and scrap paper, but I now use spreadsheets.
The graphic above is based on an excellent spreadsheet from http://serc.carleton.edu/files/introgeo/models/mathematical/examples/XLPlanck.xls. It uses Planck’s Law to calculate the black body radiation spectrum from the Sun, as observed at the top of the Earth’s Atmosphere. It also may be used to calculate the radiation spectrum from the Earth System (Atmosphere and Surface, see below for explanation) at any assumed temperature. (I will refer to this spreadsheet as “Carleton” in this posting.)
I modified the Carleton spreadsheet to compute the mean Solar radiation per square meter absorbed by the Earth System, which turns out to be 240 Watts/m^2. I then used the spreadsheet to determine the effective mean temperature of the Earth System that would emit an equal amount of energy to Space, and that turned out to be 255 Kelvins (-18ºC which is 1ºF).
Since the mean temperature at the surface of the Earth is 288 Kelvins (+15ºC which is 59ºF), that leaves 33 Kelvins (33ºC which is 58ºF) to be accounted for. Guess how we acount for it?
The yellow curve (above left) shows that Solar radiation is in a tall, narrow “shortwave” range, from about 0.1μm (microns, or millionths of a meter) to about 4μm, which we call ultra-violet, visual, and near-infrared. The vertical axis is Intensity of the radiation, measured in Watts/m^2/μm, and the horizontal axis is Wavelength, measured in μm. If you divide the area under the yellow curve into vertical strips, and add up the total area, you get 240 Watts/m^2.
Since we humans sense the visual portion of this radiation as “light”, that is the name we give it, and that has led to the false assumption that it contains no “heat” (or “thermal”) energy.
The violet curve (above right) shows that, assuming a mean temperature of 255 K, Earth System radiation to Space is in a squat, wide “longwave” range, from about 5μm to beyond 40μm, which we call mid- and far-infrared. If you divide the area under the violet curve into vertical strips, and add up the total area, you get the same 240 Watts/m^2 as is under the yellow curve.
DETAILED EXPLANATION
The graph on the left shows the actual observed Solar radiation spectrum (in red) as measured at the top of the Atmosphere. It is superimposed on a black body model (in blue) showing very good correlation. Thus, while the Sun is not exactly a black body, it is OK to assume it is for this type of “sanity check” exercise.
If you calculate the area under the curve you get about 1366 Watts/m^2. That means that a square meter of perfect black body material, held perpendicular to the Sun, would absorb 1366 Watts.
However, the Earth is not a perfect black body, neither is it a flat surface perpendicular to the Sun! So, to plot the yellow curve at the top of this posting, I had to adjust that value accordingly. There are two adjustments:
- The Earth may be approximated as a sphere, with the Sun shining on only half of it at any given time. The adjustment factor for this correction is 0.25.
- The albedo (reflectiveness) of the Earth system, primarily clouds and light-colored areas on the Surface such as ice, causes some of the Solar radiation to be reflected back out to Space without contributing any energy to the Earth System. The adjustment factor for this correction is 0.7.
After applying these adjustments, the net Solar energy absorbed by the Earth System is 240 Watts/m^2.
The graph on the right shows the black body model for an Earth System at a mean temperature of 255 K, a temperature that results in the same 240 Watts/m^2 being emitted out to Space.
Of course, the Earth System is not a perfect black body, as shown by the graph in the upper panel of the illustration below, which plots actual observations from 20 km looking down. (Adapted from Grant Petty, A First Course in Atmospheric Radiation, Figure 8.2, http://www.sundogpublishing.com/AtmosRad/Excerpts/index.html.)
The actual measured radiation is the dark squiggly curve. Note that it jigs and jags up and down between the topmost dashed curve, which is the black body spectrum for a temperature of 270 K and a lower dashed curve which is the black body spectrum for 230 K. This data was taken over the Arctic, most likely during the daytime. The Petty book also has a graph looking down from over the Tropical Pacific which ranges from 300 K down to 210 K. Observations will vary by tens of degrees from day to night, summer to winter, and Tropical to Polar.
However, it is clear that my result, based on matching 240 Watts/m^2, is within a reasonable range of the true mean temperature of the Earth System as viewed from Space.
NOTE ABOUT THE ABOVE ILLUSTRATION
WUWT readers will notice some apparent inconsistencies in the graphs above. The top and bottom panels, from Petty, peak at 15μm to 20μm, while the purple, blue, and black curves in the middle panel, and the Earth System curves from the Carleton spreadsheet I used (see above) peak in the 9μm to 11μm range. Also, the Petty black body curves peak at a “Radiance” around 100 mW/m^2/sr cm^-1 while the black body curves from Carleton peak at an “Intensity” of around 14 W/m^2/μm. Furthermore, if you look closely at the Petty curves, the labels on the black body curves are mirror image! What is going on?
Well, I know some of the reasons, but not all. (I hope commenters who are more fluent in this than I am will confirm my explanations and provide more information about the differences between “Radiance” and “Intensity”.) I have Googled and Wikied the Internet and am still somewhat confused. Here is what I know:
- The horizontal axis in Petty’s plots are what he calls “Wavenumber”, increasing from left to right, which is the number of waves that fit into a cm (centimeter, one hundredth of a meter).
- This is proportional to the frequency of the radiation, and the frequency is the inverse of the wavelength. Thus, his plots are the mirror image of plots based on wavelength increasing from left to right.
- The spreadsheet I used, and my previous experience with visual, and near-, mid-, and far-IR as used in military systems, always uses wavelength increasing from left to right.
- So, when I constructed the above illustration, I reversed Petty’s curves, which explains why the labels on the black body curves are mirror image.
- Fortunately, Petty also included a wavelength legend, which I faithfully reproduced, in non-mirror image, at the top of each plot.
But, that still does not explain why the Petty black body curves peak at a longer wavelength than the Carleton spreadsheet and other graphics on the Internet. I tried to reproduce Petty’s blackbody curves by multiplying the Carleton values by the wavelength (μm) and that did not move the peak to the right enough. So, I multiplied by the wavelength again (μm^2) and, voila, the peaks agreed! (I hope some WUWT reader will explain why the Petty graphs have this perverse effect. advTHANKSance!)
ANSWERING THE OBJECTIONS TO BASIC ATMOSPHERIC “GREENHOUSE EFFECT” SCIENCE
First of all, let me be clear where I am coming from. I’m a Lukewarmer-Skeptic who accepts that H2O, CO2 and other so-called “greenhouse gases” in the Atmosphere do cause the mean temperature of the Earth Surface and Atmosphere to be higher than they would be if everything was the same (Solar radiation, Earth System Albedo, …) but the Atmosphere was pure nitrogen. The main scientific question for me, is how much does the increase in human-caused CO2 and human-caused albedo reduction increase the mean temperature above what it would be with natural cycles and processes? My answer is “not much”, because perhaps 0.1ºC to 0.2ºC of the supposed 0.8ºC increase since 1880 is due to human activities. The rest is due to natural cycles and processes over which we humans have no control. The main public policy question for me, is how much should we (society) do about it? Again, my answer is “not much”, because the effect is small and a limited increase in temperatures and CO2 may turn out to have a net benefit.
So, my motivation for this Visualizing series is not to add to the Alarmist “the sky is falling” panic, but rather to help my fellow Skeptics avoid the natural temptation to fall into an “equal and opposite” falsehood, which some of those on my side, who I call “Disbelievers”, do when they fail to acknowledge the basic facts of the role of H2O and CO2 and other gases in helping to keep temperatures in a livable range.
Objection #1: Visual and near-visual radiation is merely “light” which lacks the “quality” or “oomph” to impart warmth to objects upon which it happens to fall.
Answer #1: A NASA webpage targeted at children is sometimes cited because they say the near-IR beam from a TV remote control is not warm to the touch. Of course, that is not because it is near-visual radiation, but rather because it is very low power. All energy is fungible, and can be changed from one form to another. Thus, the 240 Watts/m^2 of visible and near-visible Solar energy that reaches and is absorbed by the Earth System, has the effect of warming the Earth System exactly as much as an equal number of Watts/m^2 of “thermal” mid- and far-IR radiation.
Objection #2: The Atmosphere, which is cooler than the Earth Surface, cannot warm the Earth Surface.
Answer #2: The Second law of Thermodynamics is often cited as the source of this falsehood. The correct interpretation is that the Second Law refers to net warming, which can only pass from the warmer to the cooler object. The back-radiation from the Atmosphere to the Earth Surface has been measured (see lower panel in the above illustration). All matter above absolute zero emits radiation and, once emitted, that radiation does not know if it is travelling from a warmer to a cooler surface or vice-versa. Once it arrives it will either be reflected or absorbed, according to its wavelength and the characteristics of the material it happens to impact.
Objection #3: The Atmospheric “Greenhouse Effect” is fictional. A glass greenhouse works mainly by preventing or reducing convection and the Atmosphere does not work that way at all.
Answer #3: I always try to put “scare quotes” around the word “greenhouse” unless referring to the glass variety because the term is misleading. Yes, a glass greenhouse works by restricting convection, and the fact that glass passes shortwave radiation and not longwave makes only a minor contribution. Thus, I agree it is unfortunate that the established term for the Atmospheric warming effect is a bit of a misnomer. However, we are stuck with it. But, enough of semantics. Notice that the Earth System mean temperature I had to use to provide 240 Watts/m^2 of radiation to Space to balance the input absorbed from by the Earth System from the Sun was 255 K. However, the actual mean temperature at the Surface is closer to 288 K. How to explain the extra 33 K (33ºC or 58ºF)? The only rational explanation is the back-radiation from the Atmosphere to the Surface.
Wayne postulates:
“#4) At a macro level once energy is within the atmosphere that portion of energy is committed to be ejected to space for the average atmosphere’s temperature is always lower with increased altitude. (See #2, #3)”
Let me see if I can convince you (and others) that at a micro level, energy can travel either way.
1) Suppose you have a convection current moving upward @ur momisugly 1 m/s. It might be tempting to say air molecules are “committed” to move upward because the net speed is 1 m/s. But the random thermal motion of air molecules is about 400-500 m/s (depending on temperature and just which type of molecule we are talking about).
The speed of the molecules could be stated as 1 +/- 500 m/s. A given molecule could be moving upward at 203 m/s one moment and a moment later it might be heading downward at -337 m/s. If you followed a given molecule, it would take a long time before you could determine that there was a breeze.
Or put another way, if you look at the bottom of a tiny cube (say 10^-8 m on a side), nearly as many molecules will be passing downward as upward. in some second, it is possible that more molecules actually passed down than up even when the air is blowing upward!
2) Suppose a wire is hooked to a battery and we look at a cross-section of that wire. Electrons move:
a) only from + to –
b) only from – to +
c) about evenly in both directions.
If you answer (a), you are thinking of conventional current, not movement of electrons.
If you answer (b), you have had a bit more training in circuits.
If you answer (c), you are correct.
Conduction electrons have a mean speed around 10^6 m/s (google “Fermi energy” if you want to know more).. A typical drift velocity of electrons in a wire is 0.001 m/s. This is an even more extreme case compared to (1). The conduction electrons are moving at 0.001 m/s +/- 1,000,000 m/s!
3) Consider two identical blocks of metal in contact, one slightly warmer than the other. The average energy of an atom in each block will be 1/2 kT per degree of freedom. For the sake of argument, suppose the average energy in one is E and the average energy of the other is 1.1 E (ie it is 1.1 times hotter, eg one might be 300 K and the other might be 330 K).
Energy is transferred by conduction when an atom of one block hits an atom of the other block. There are plenty of atoms in the cold block with an energy > 2E. There are plenty of atoms in the warm block with an energy < 0.5 E. If an above average atom from the cold block hits a below average atom from the warm block, the warm block will gain energy!
Of course, if you average enough collisions, the net flow of energy is from the warm to the cold block, but individual collisions can transfer energy either way. (This might be labeled "back-conduction" and "forward-conduction", but I can think of any cases practical where "back-conduction" is important as a separate concept from net conduction.)
And the conclusion, of course, is …
Suppose an air molecule with above average energy emits a photon with above average energy to a surface atom with below average energy ….
So we can state
“#4b) At a micro level once energy is within the atmosphere that portion of energy is will go almost randomly in any direction. Nearly 1/2 will go downward, accounting for the ~330 W/m^2. “
Myrrh expounds:
“It would be worthy of a Nobel Prize for Physics for you to show that the tried and tested and well understood in Science 2nd Law breaks down at this level.”
With all due respect, until you have taken a graduate level course in thermodynamics and statistical mechanics, you are not even CLOSE to being able to decide what is worthy of a Nobel Prize related to the 2nd Law.
I suspect that 2 or three of us here HAVE taken graduate level statistical mechanics. I suspect several others have at least taken upper level undergraduate level thermodynamics classes.
If you REALLY want to discuss statistical mechanics, then I would suggest working through the free course from MIT http://ocw.mit.edu/courses/physics/8-333-statistical-mechanics-i-statistical-mechanics-of-particles-fall-2007/syllabus/ In particular, work through the ideas of microcanonical, canonical and grand canonical ensembles and how they relate to entropy and the 2nd Law.
Ira Glickstein, PhD states his 9 claims in a posting on May 14, 2011 at 3:49 pm:
I’ll “focus” mainly on the last one here:
“——————- Claim 9: Accounting.
(a) 390 Watts/m^2 = Radiative energy input from the Surface to the Atmosphere (claim #7).
(b) 70 Watts/m^2 = Radiative energy input from the Sun to the Atmosphere (claim #5).
(c) 100 Watts/m^2 = Net convective and water cycle input from the Surface to the Atmosphere (Claim #9).
(d) 560 Watts/m^2 = Total input to the Atmosphere from all sources.
(e) 240 Watts/m^2 = Output of the Atmosphere towards Space (claim #4).
(f) 320 Watts/m^2 = Atmospheric emission towards the Surface (simple arithmetic: 560 – 240 = 320).
Evidence: Simple arithmetic. Close enough for a “sanity check”. Any objection to that?”
This, his last “Claim” is the “Main Claim” that keeps me from readily accepting the rest of the claims.
My objection to this one is that “Kirchhoff’s Law of thermal radiation states”, as far as I can recall, and as Wikipedia writes is that:
“At thermal equilibrium, the emissivity of a body (or surface) equals its absorptivity.”
Our nearest neighbor in space which must receive a very close to similar radiation in Watts per m² to that which the Earth does, would be a very cold ball indeed if it’s surface was to receive 240 W/m² and at the same time emit 390 W/m². – As I said in my comment on May 13, 2011 at 5:12 pm: “I doubt very much that the surface knew when it emitted the 324 extra W/m² of energy from it’s “energy store” that the atmosphere was going to send it straight back and thus conserve that energy on it’s behalf.
Ira, you say it is “Simple arithmetic” – therefore ok, – so my arithmetic may be simpler than the simplest of all arithmetic(s), but it is still good enough to understand that there is not necessarily the arithmetic that is wrong.
If surface radiation has been measured and does indeed average 390 W/m² then either the stated “input wattage” (your 170 Watts/m^2) is incorrect or the “Earth System”, Globe + Atmosphere, must be looked at as one complete unit where internal heat exchange uses or looses 390 – 170 = 220 W/m², or – Kirchhoff was wrong but nobody, as far as I know, advocates that.
And then lastly in Claim 9 (f) you say:”320 Watts/m^2 = Atmospheric emission towards the Surface (simple arithmetic: 560 – 240 = 320).”
My questions here are: How is it possible for the Atmosphere to radiate 240 W/m² towards space and 320 W/m² towards the surface? – And, what is the “selection method” used by the Atmosphere to enable it to emit more in one direction than it does in the other?
And lastly Ira, think of this one; if you was to substitute 390 W/m² & al with, say 3.9
°C & pro rata, – then, how much would it add to the average surface temperature of 15 °C if 3.9 °C was removed from the surface and just 3.24 °C was returned?
Joel Shore says:
May 14, 2011 at 6:55 pm
It’s tough not getting frustrated, isn’t it? 🙂
I hope you know that many skeptics are very well informed and have no misconceptions about the most basic physics of greenhouse gases. I have tried many times in many ways to explain that greenhouse gases act as insulation allowing visible light from the sun to pass straight through unimpeded to heat the ocean but do not allow infrared light from the ocean to pass through unimpeded on its way out the door to space. The property of being transparent to visible light and opaque to infrared doesn’t seem complex or difficult.
I’d be interested in your thoughts on liquid water acting in the same way. Water is fairly transparent to visible light allowing sunlight to penetrate to a depth of about 100 meters before it is completely absorbed. On the other hand water is opaque to infrared light. Infrared light is absorbed in the first micrometer of water.
So the sun can heat the ocean to a depth of 100 meters but the energy absorbed at that depth can’t escape as infrared because water is opaque to it. Liquid water is thus a GHF (greenhouse fluid). Actually gases are fluid so there’s essentially no difference between a GHG and GHF except for density and viscosity.
So how does the visible light absorbed by the ocean deeper than 1 micrometer escape? If radiative escape is blocked then that only leaves convection and conduction to get the deeper water to the surface where it can escape through radiation, conduction to the atmosphere, and evaporation.
My big question is about whether conduction and convection are as efficient at getting energy to the surface as sunlight is at adding energy at depth.
I don’t believe that it is as efficient and there is in fact a greenhouse effect the comes solely from the fact that the earth is mostly covered by water.
I’ll look into it further.
Tim, quit giving me homework. Give me an direct answer, and when I question it, give me the answer in the specific form I’ve asked for it, instead of prevaricating; as you’ve done yet again. I have yet to see any basic science from any of you.
For example, take Ira’s opening here: “..that all energy is fungible” – what on earth is that supposed to mean in context of his post?
So my cup of coffee can turn into a crystal glass bubbling with champagne? Of course it can, in process, and in accordance with the nature of the properties and the limits of their changes at each and every step.
Prove, say, at the photon level that a photon from a colder transfers/add/converts to heat the warmer water added to it in a cup when they are brought into contact.
A statistical analysis made with complete disregard for the actual possibilities of a process taking place is without logical parameters.
richard verney
Start of with an object radiating because it contains an energy source.
Bring another passive object at a lower temperature near to the first object.
Switch off the power source to the first object
The passive objects temperature increases and the hotter will decrease.
The passive object will be returning some of the energy that was supplied to it by the first object.
Its obvious that the first objects temperature will not increase by absorbing energy it initially supplied to the passive object.
Both objects will exchange energy ( more from the hotter one).
Eventually both objects will be at the same temperature and exchange equal quantities of radiation.
If the power supply was left on the hotter ones temperature will increase in temperature because the passive one acts as an insulator and the radiation it returns can be thought of as the radiative component of insulation.
Radiation in this example is a two way process
Energy exchange is a two way process
Spontaneous Heat transfer is a one way process always from hotter to colder never the reverse.
Heat is always energy but energy is not always heat.
The transfer of heat is the province of the second law of thermodynamics.
Its easy to get the quantities muddled .
Even Physicists if their not careful, get confused.
Joel Shore and Arthur Smith and four other “experts” managed to compose a paper getting very confused about Heat.
Now that is inexcusable.
Particularly when I explained to Joe l (here on WUWT) two months before the papers publication exactly the same points I am making here.
Thanks jae (or JAE) for the suggestion, and here is one for you:
Don’t criticize anyone until you’ve walked a mile in their shoes.
(By doing that, you’ll be a mile away. And, you’ll have their shoes :^)
Myrrh says:
Exactly…Which is why when people make analogies, they should (like Ira, myself, Tim, Dave) actually understand the underlying physics and equations that actually describe the process. We do. You don’t. Therefore, any analogies that you make are based on nonsense, not physics.
wayne says:
Is there any actual physics textbook that teaches your version of “proper physics”? I ask that because I have seen lots of physics textbooks but they all seem to teach improper physics…So, I am wondering where one can find this proper physics written down. Certainly, there must be one reputable source that you can cite?
Can someone help me out here?
Here is a graph of liquid water absorption across a large spectrum from ultraviolet to microwave.
As on can see water absorbs strongly at all frequencies other than visible light. This is why light from the sun can penetrate the ocean to a depth of about 100 meters.
This is exactly the properties of a greenhouse gas that makes them a greenhouse gas – strong absorber of infrared light and weak absorber of visible light.
The ocean therefore must be a greenhouse fluid.
So far I can find no discussion of water as a greenhouse fluid anywhere. Surely someone other than me has noticed that water has the same properties as greenhouse gases and therefore must have a greenhouse effect.
Maybe I’m not googling for the right words/phrases. No matter how I try when combining water and greenhouse effect in the same search you’re inundated (pun intended) by hits about greenhouse gases. The search for water as a greenhouse fluid is buried in the noise of atmospheric greenhouse effects.
Can someone help me out here? I’m crowd sourcing for an answer.
Forgot the add link to radiative absorption spectrum of liquid water:
http://en.wikipedia.org/wiki/File:Water_absorption_spectrum.png
Myrrh says:
First of all, an issue of terminology that has sometimes tripped me up too (much to Bryan’s enjoyment): “Heat” is the name given to the net energy flow, so it is not technically correct to talk about “heat from colder to hotter”. Rather, it is most correct to say that the heat, i.e., net flow of energy, is always from hotter to colder but that there are energy exchanges going both ways, with the energy flow from hotter to colder always being larger than that from colder to hotter.
At any rate, I have a question for you Myrrh: In your view, when exactly did these incorrect concepts take over physics? I have the textbook here that I used as an undergraduate. It is “Introduction to Statistical Mechanics and Thermodynamics” by Keith Stowe, copyright 1984. (We actually used the book when it was essentially new…in 1985, plus or minus a year.) Here is some of what it says about the Second Law:
O H Dahlsveen says:
I am actually pretty annoyed that you bring this up again given how much time and energy we (both Tim and I) expended explaining it to you in the last thread:
http://wattsupwiththat.com/2011/03/10/visualizing-the-greenhouse-effect-emission-spectra/#comment-621266
http://wattsupwiththat.com/2011/03/10/visualizing-the-greenhouse-effect-emission-spectra/#comment-621292
http://wattsupwiththat.com/2011/03/10/visualizing-the-greenhouse-effect-emission-spectra/#comment-621474
http://wattsupwiththat.com/2011/03/10/visualizing-the-greenhouse-effect-emission-spectra/#comment-621511
Why should we waste our time explaining these things to you if you will just continue to recycle your questions again and again?
Dave Springer says:
Indeed!
Yeah…And, I am glad that many of you have become more vociferous in trying to get the others to understand this basic physics, although it seems to be a losing battle in many cases.
Well, conduction may not do that much, but I think convection will. I.e., like in the atmosphere, convection will probably try to move things back to the stability limit, which means a much smaller lapse rate in a liquid medium than in a more-compressible gaseous medium.
An interesting idea. However, my guess (admittedly without much thought) is that this will be very small exactly because convection in a liquid will place a much lower limit on lapse rates than convection in a gaseous medium. Also, although light can make it down to large depths, I don’t think the heating is as concentrated at the bottom of the ocean as it is at the bottom of the atmosphere (although this may depend on the ocean depth…e.g., how much light gets all the way down to the ocean floor).
Dave Springer says:
May 15, 2011 at 7:40 am
Interesting concept. I tried Googling “water absorption spectrum pH” as I suspected there may be pH-related changes in the absorptivity of water (there are). I agree, surely there must be some serious literature on this ??
I thought that the way this page started, it might touch upon your question, but it doesn’t really, although it’s an interesting resource:
http://www.btinternet.com/~martin.chaplin/vibrat.html#uv
A scientist said cogently, as his hand came from his pants-
“I understand an elephant is fetching mighty grants!”
A cohort, then, who felt the wind emerging from his ass,
declared “I see the elephant is very like a gas!”
“Then they began to quarrel, shouting, ‘Yes it is!’ ‘No, it is not!’ ‘An elephant is not that!’ ‘Yes, it’s like that!’ and so on, till they came to blows over the matter.
“Just so are these preachers and scholars holding various views blind and unseeing…. In their ignorance they are by nature quarrelsome, wrangling, and disputatious, each maintaining reality is thus and thus.”
Weather used to be ‘the safe topic’ before it became blood sport for sophomores with no other outlet for their raging hormones.
More circus, less bread! More taxes to pay for this! The alto section of the choir can always use more eunuchs, too.
philincalifornia says:
May 15, 2011 at 9:02 am
Yeah, I found that page. It’s about as close as I got but after all the nice info it focuses on water vapor in atmosphere. Nothing I could find anywhere about the same effect from liquid water. Presumably the effect is much greater in liquid water since the first 30 feet of it is equal the entire weight of the atmosphere above it and the first foot of it equal to the weight of all the water vapor above it.
I still can’t believe the seeming utter dearth of information pertaining to liquid water as a greenhouse fluid given it obviously has the required properties of transparency to visible light and opacity to infrared.
O H Dahlsveen says:
May 15, 2011 at 7:00 am
My questions here are: How is it possible for the Atmosphere to radiate 240 W/m² towards space and 320 W/m² towards the surface? – And, what is the “selection method” used by the Atmosphere to enable it to emit more in one direction than it does in the other?
This is rather easy – at some frequencies, the atmosphere is opaque. As a result, the warmer lower atmosphere emits more energy towards the surface than the cold upper atmosphere emits towards space.
Come on guys, this stuff is really easy. Several people keep arguing that raising the average temperature from -18C to 15C violates the second law. However, they are ignoring the fact that the actual temperature fluctuates from high values to low values. The correct analysis is for recognize that, without an atmosphere, the daily surface temperature would raise to about 120C (249F). When the Sun goes down, the surface wants to cool to about 45K. (Notice, this is not the 3K background everyone keeps talking about. The difference is due to the zodiacal light that shines 24/7.) What the atmosphere does is to cool the surface so that the daily maximum value is only 57C (135F). As the temperature drops at night, the atmosphere returns some of the energy it stored during the day so that the minimum temperature is only slightly below the maximum. When analyzed like this, it is obvious that the Second Law is not violated.
Get it? Instead of cooling to -18C, the surface cools to 15C. It isn’t being heated by the atmosphere. It simply does not cool as much as it would without an atmosphere.
At the poles, it works a little different. During the long night, the atmosphere is always warmer than the surface. (This has been measured with thermometers tied to balloons.) As a result, the only source of winter heat is the radiation from the atmosphere.
Joel Shore says:
Re “An analogy which has no bearing on the example being explained is worthless in science.”
Exactly.. Which is why when people make analogies, they should (like Ira, myself, Tim and Dave) actually understand they underlying physics and equations that actually describe the process. We do. You don’t. Therefore, any analogies that you make are based on nonsense, not physics.
Well, you can keep claiming you and your gang understand, but I’ve yet to see real evidence of it. I don’t have to have a science PhD to think logically..
If all you can reply to my questions is that you are so much more educated in this science so it follows that whatever you say it correct, then that is illogical, and against the principles of Science; that is religion claiming its priesthood knows all the answers. I thought this was a Science blog.
Take for example the oft touted analogy of “insulating” and “insulating blanket”, which anyone with half a brain and without science background can look up to check what that means as an analogy – that it’s a blanket among more than 99.95% non-blanket. And which, coupled with the claim that this “insulating blanket” is well mixed in that 99.95%, that doesn’t even count as a stitch.
You’ve shown immediately and obviously that you don’t have the skills you’ve just claimed, because your gang’s analogy is demonstrably nonsense.
If you can’t defend your science claims with anything better than that, it would be really dumb of me to take your claims about your science superiority seriously.
So I don’t.
This gets much closer:
JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 108, NO. C5, 3146, doi:10.1029/2002JC001584, 2003
Seasonal mixed layer heat budget of the tropical Atlantic Ocean
This is fatal for the GHG hypothesis. It is experimentally found that the ocean absorbs 200 w/m2 of visible light and only loses 50 w/m2 via longwave emission.
As I suspected the energy is primarily carried off in latent heat of vaporization.
In a nutshell: greenhouse gases only get a chance to act on 25% of the energy being emitted by the ocean and CO2 with its narrow absorption bands only gets to act on a fraction of that 25%.
Moreover the paper above discusses how solar energy absorbed by the ocean in the humid summer remains trapped until dry winds in the winter remove through evaporation.
I friggin’ knew I had to be right. The goddamn ocean is responsible for most of the greenhouse effect. Atmospheric gases play only a small role.
There’s an elephant in the room responsible for most of the 33K greenhouse warming on this planet. That elephant’s name is “the global ocean”.
If water vapor and CO2 had no IR absorptivity we’d still have most of the greenhouse warming because it’s liquid water that generates most of it!
Now the question is why no one talks about it. If a physics piker like notices that water is transparent to visible light and opaque to infrared, thus fulfilling the requirement to act as a greenhouse agent, the surely others must have noticed as well. I don’t get it. This is too obvious but try as I might I can find no flaw in the reasoning.
Dave Springer:
No…In addition to the objections that I raised above, how is the liquid water in the oceans going to cause the temperature at the earth’s surface to be higher than required by simple energy balance considerations? The substances that do this have to be above the earth’s surface.
Myrrh says:
Myrrh: There is not a scientist on this planet who can dispel the scientific delusions that you live under. As David M Hoffer has pointed out, you are utterly and completely impervious to science and reason.
We can’t fight ignorance when someone is dead-set on remaining ignorant. I am sorry but it is just not possible.
Dave Springer says:
May 15, 2011 at 9:57 am
Nothing I could find anywhere about the same effect from liquid water. Presumably the effect is much greater in liquid water since the first 30 feet of it is equal the entire weight of the atmosphere above it and the first foot of it equal to the weight of all the water vapor above it.
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Maybe it’s just a nomenclature thing. Since no one doubts the fact that the oceans absorb and retain energy from the sun, your visible light observation has got lost in the noise.
Given the parameters you mention above, I can’t help thinking that you might be on to something important here, i.e. with respect to changes due to dissolved CO2 and the attendant, albeit small pH changes. However, since there does not appear to be much (Googlable) literature on this, it’s difficult to start trying to assess the magnitude of, or even in which direction this potential feedback could be.
Apologies for extrapolating from your initial observation, but you piqued my curiosity.