In Part One we looked at the absorption of solar and atmospheric radiation (aka “back radiation”) in the ocean.
About half of the solar energy is absorbed in the first meter, but most of the DLR (downward longwave radiation), or “back radiation”, from the atmosphere is absorbed in the first few microns of the ocean surface. And all of the DLR is absorbed in the first 0.1mm of the ocean.
Warmer water is less dense (more buoyant) than cooler water. Less dense water rises to the top over more dense water and so a surface being heated at the very top is “stratified”. This really means that there is no tendency for water from below to displace water above. How then can heat from the top layer of the atmosphere make it into the ocean?
In Part Two we looked first at what would happen if the “back radiation” was absorbed and immediately consumed in the process of evaporation. The ocean would be much colder.
Then we looked at simple models of heating from solar radiation and DLR if there was no convection (within the ocean). Because the conductivity of water is quite low the results are strange – the water boils around 1m down. Of course, this doesn’t happen – the water heats up, expands and rises. This is “natural convection”. The article touched on this and also on “forced convection” via the effects of the wind “stirring” the water.
The ocean is a fascinating place, very complex, but of course the basics of heat transfer still stay the same.
How Does Heat Move Through the Ocean?
There are competing forces, as you might expect in a dynamic system.
In “broadbrush”:
- the sun heats the ocean, mostly in the first few meters
- the ocean heats the boundary layer of the atmosphere via convection
- the ocean heats the lower atmosphere via radiation
Huge amounts of energy also move from the equator to the poles, approximately 50:50 via the ocean and the atmosphere.
To consider the complete picture of the energy transfer – the atmosphere also radiates to the ocean (see The Amazing Case of “Back Radiation” -Part One and the following parts). The issue that was probably implied in the original question was “if back radiation increases due to more CO2 (or other trace gas increases) will that energy be mixed into the ocean?”.
If we “dive in” to a little more detail, as in Part Two, then we see that solar radiation is absorbed in the top few meters of the ocean and as a consequence, this ocean heat rises to the surface.
In this article we will try to understand more about how the upper layer of the ocean mixes.
Temperature – Depth Profile vs Wind Speed and SST Variation
There is a huge wealth of experimental results in ocean “heat budgets” and temperature profiles.
First, 35 vertical temperature profiles during the warming and cooling phases of the diurnal cycle at low wind speed from Soloviev & Lukas (1997):
Note: Each successive temperature profile is artificially shifted in temperature for comparison purposes
From Price and Weller (1986) we see another example of how the vertical temperature profile goes from “well-mixed” under higher winds to a definite temperature profile (during the day) under light winds:
With these temperature profiles we also see the effect of the day-night variation. Regardless of wind speed, at night the temperature profile shows that the ocean has become well mixed.
Now temperature profiles under different wind speeds from Soloviev & Lukas (1997):
COARE is the coupled ocean-atmosphere response experiment, and the area of study is in the Western Pacific from the R.V. Moana Wave. What this diagram shows is very interesting, but not surprising:
- in higher wind speeds (A) the ocean is very well mixed (the temperature is the same at the surface as 10m depth)
- in very calm conditions (C) there is a very pronounced temperature profile with depth
- in between (B), the ocean temperature profile shows a transition between these two results
Another dataset from Soloviev & Lukas (1997) – time-series of temperature, salinity and density on one day:
Note: there was a rain event at 19:00
The variation in surface temperature (SST) from day to night indicates the same effect taking place. During light winds in tropical waters very large temperature variations can be seen (up to 2-3°C and even 5°C), whereas more generally the SST diurnal variation is less than 0.5°C.
The SST measurements were done by the HCMR (Heat Capacity Mapping Radiometer) and the study area is East of Sardinia in the Mediterranean.
From Kawai & Wada (2007) an interesting time-based dataset of temperature vs depth against solar flux and wind speed:
Wind-Induced Convection and Diurnal Cycle
At night the surface of the ocean cools rapidly via radiation – but is not receiving any heat via solar radiation. Therefore, the top surface of the ocean cools – and so it sinks.
Therefore, every night, the ocean heat in the top few meters becomes very well mixed.
During the day (and the night), when the wind picks up over the surface two effects take place. One is that the top few meters of the ocean become well-mixed due to wind-induced stirring. The other effect is that the surface cools more rapidly than normal due to convective cooling (convective heat transfer to the atmosphere), and therefore is more likely to sink.
A Brief Digression on Cameos
Not only do climate scientists do a lot of experiments, but sometimes they even come together for a cameo role just because the stars align:
Let’s not pretend this paper was anything other than what it obviously appears to be..
Conclusion
The aim of this article is just to show some field research about how the top layer of the ocean mixes. Wind and diurnal cooling mix heat from the surface into the top few meters of the ocean.
In the next article we will analyze the possible effect of a little more “back radiation” in the light of these results.
Update – Does Back Radiation “Heat” the Ocean? – Part Four
References
Observation of large diurnal warming events in the near-surface layer of the western equatorial Pacific warm pool, Soloviev & Lukas, Deep Sea Research Part I: Oceanographic Research Papers (1997)
Large Diurnal Heating of the Sea Surface Observed by the HCMR Experiment, Deschamps & Frouin, Journal of Physical Oceanography (1984)
Diurnal Sea Surface Temperature Variation and Its Impact on the Atmosphere and Ocean: A Review, Kawai & Wada, Journal of Oceanography (2007)
Diurnal cycling: Observations and models of the upper ocean response to diurnal heating, cooling, and wind mixing, Price & Weller, Journal of Geophysical Research (1986)
Notes
Note 1 (added Dec 6th) – To avoid upsetting the purists, when we say “does back-radiation heat the ocean?” what we mean is, “does back-radiation affect the temperature of the ocean?”
Some people get upset if we use the term heat, and object that heat is the net of the two way process of energy exchange. It’s not too important for most of us. I only mention it to make it clear that if the colder atmosphere transfers energy to the ocean then more energy goes in the reverse direction.
It is a dull point.
[…] on December 5, 2010 at 12:25 pm | Reply Does Back Radiation “Heat” the Ocean? – Part Three « The Science of Doom […]
I am a lay person trying to understand this.
In an article on RC, Peter Minnett explained that back radiation heated the top of the skin layer, the first few microns, and that the resulting temperature gradient – very hot on the top of the skin layer (where most of the back radiation is absorbed) and cool at the bottom of the skin layer – slowed the movement of heat (presumably all from SW) through the skin layer, and that is how GHGs heat the oceans.
Did Minnett say that it was hot at the top of the skin layer and cool at the bottom? I couldn’t find a clear statement on that at all (there should have been). But I took Fig 2 to be a plot of (skin (top) – bulk) vs LW, with two important signs:
1. skin-bulk is negative – ie very top surface cooler than below
2. Nett LW is negative – ie nett flux is upward, not down.
Nick, I think the clearest statement of it was made in a response by Stefan in the comments at 6, 5 September 2006 at 5:00 PM:
[ ….Thus we are talking not about the gradient between sea surface and overlying air, but we are talking about the gradient through the skin – i.e., the water temperature difference between the top and bottom of the skin layer, which controls how heat flows across this layer, from the bulk of ocean water below to the surface. Obviously, if you heat the top of the skin layer, this reduces the heat flow across this layer from below. Clear? Or still confusing? -stefan]
Well, Stefan seems unsure of its clarity 😉 But I’m querying your statement that it’s hot at the top and cool at the bottom, and I don’t think Stefan is saying that either. I think what they all say is what S0D’s graphs show below. It’s cooler at the top, but down LW makes it less cooler.
Like I say, Nick, I’m trying to understand. I stand corrected. The bottom side of the skin layer is actually warmer than the top of the skin layer, but less so because of back radiation. Can I say it like that?
So if the day side of the graph were redrawn with no back radiation, how would the red and orange stars reposition? Both to the left of the grey star, SST int?
JCH,
No, I think it would be a similar profile; the gradients would be the same. Just a lot colder.
How so Nick? The net effect of long wave radiation is a ~66W/m^2 cooling of the ocean surface.
If there were no longwave radiation, the ocean wouldn’t be cooled as effectively as it is, so it’s temperature would rise, not fall.
I think these “What would happen if we suddenly removed ____” type arguments are fraught with potential misunderstanding, because of the multiple roles natural phenomena play.
I didn’t want to “hijack” the main article but there is an important explanation about “surface temperatures”. With apologies for the very lengthy quote from Kawai & Wada (2007):
[extract]
A sharp temperature gradient sometimes appears above 1-m depth in the daytime. The large temperature difference between the sea surface and about 1-m depth, where ships and buoys usually measure the seawater temperature as “SST”, has been recognized as one of the major sources of error in satellite-derived SST. The satellite infrared sensor, microwave sensor, and in situ sensors observe “different sea surfaces”, i.e., skin, subskin, and a depth of one or a few meters, respectively.
Hence it was indispensable to define SST exactly and consider careful treatment of different SSTs when producing an accurate SST dataset. The Global Ocean Data Assimilation Experiment (GODAE) High-Resolution SST Pilot Project (GHRSST-PP) Science Team has been doing work on coordinating a new generation of global, multi-sensor, high-resolution SST products for the benefit of the operational and scientific community (Donlon et al., 2007).
This Science Team has defined five kinds of SST: interface SST (SSTint), skin SST (SSTskin), subskin SST (SSTsubskin), sea temperature at depth (SSTdepth), and foundation SST (SSTfnd) (Donlon and the GHRSST-PP Science Team, 2005). A schematic picture of the vertical temperature profile is shown in Fig. 1, and the definitions of the SSTs are explained in Table 1.
In actuality, we cannot know SSTint even with current technology (Donlon et al.,2002), and SSTskin is usually utilized as a substitute forSSTint on the assumption that SSTskin is close enough to the true SSTint. The in situ SST measured at about 1-m depth or deeper has been called “bulk” SST. The Science Team recommends using “SSTdepth” rather than the conventional term “bulk SST” referring to an in situ SST measurement made at 1-m depth as SST1m, for example.
This terminology is introduced to encourage reporting of the measurement depth along with the temperature, because, as depicted in Fig. 1, the temperature can change drastically with depth when the diurnal thermocline is formed. The new concept of “foundation SST” is introduced as a more precise, well-defined quantity instead of previous, loosely-defined “bulk” SST, which is affected by the diurnal warming. SSTfnd will be similar to a nighttime minimum or pre-dawn value at depths of ~1–5m, but note that this depth is only a rough estimate and can deviate from this range in some cases. This paper basically adopts the terminology proposed by Donlon and the GHRSST-PP Science Team (2005). When referring to the temperature near the surface in a general sense, loosely, the authors simply use “SST”..
.. The atmosphere senses only the exact interface between the atmosphere and the ocean. Hence we have to know SSTint (or SSTskin practically) and its diurnal variation for accurate estimation of air-sea heat and gas fluxes (e.g., Sarmiento and Sundquist, 1992; Fairall et al., 1996). If the temperature at a few meters depth is used as SSTint in a flux calculation, the atmosphere will receive incorrect heat and water vapor from the ocean. This impact is not always negligible, as discussed in Sections 5 and 6.
[end of extract]
Scienceofdoom,
Unless the sea surface temperature is lower than the atmospheric temperature, back radiation is (on the average) is lower that outward radiation. If that is so, the atmosphere does not heat the ocean (on the average) by back radiation. Heat transfer is based on the difference of the energy flows, not the individual levels, and always is in the direction of positive energy flow. Obviously at night, or near the poles, the lapse rate and surface temperature may result in a locally hotter atmosphere (mainly due to surface radiation heat loss through the optical transparent “windows” in the atmosphere), so there can be heating from back radiation, and even from convection/conduction, but these are not on the average.
Semantics again. SST is higher than it would be in the absence of radiation from the atmosphere, so in the broader meaning of heat, back radiation does, in fact, heat the ocean. It’s only when you restrict the meaning of the word heat to one specific definition a la Bryan that you can say that DLR doesn’t heat the ocean. I see a distinction without a difference between ‘heats the ocean’ and ‘makes the ocean warmer’.
DeWitt,
You appear to not accept that the higher surface and lower atmosphere temperature are due to the lapse rate added to the upper atmosphere temperature (which is due to radiation insulation moving the level up) of balanced incoming and outgoing radiation. Keep in mind that LTE and free convection prevent back radiation or even forward radiation heating (on the average). The higher radiation levels due to the temperature being higher than for no greenhouse gas is exactly an effect, not interchangeable with being a cause. This is not semantics.
There are clear local exceptions (e.g., at night or if convection of air or water made the surface cooler than the local air above it), but on the average, the air is always heated by the ground and water on the Earth.
DeWitt,
As an aside, the situation on Venus is not the same as Earth. Most of the solar energy is absorbed in the atmosphere (and clouds) before it reaches the ground, although some reaches the ground. The ground is maintained near the lower atmosphere temperature by alternately being heated by the small absorbed solar heating during the day combined with downward convection and a very small amount of long wave radiation from the atmosphere at night, then transporting heat (mainly by convection) up from the surface when the surface is warmer than the atmosphere locally.
DeWitt Payne
Your apparent endorsement of SoDs use of the vernacular meaning of HEAT rather than the scientific meaning of HEAT is to be regretted.
What is to be gained when there is confusion and ambiguity?
Perhaps you think that because you have noticed SoDs past careless use you can make allowances and that its OK?
Recently you gave a reference to John Denker who find the use of certain terms “cramped”.
He is a big fan of Feynman and quotes him often.
Yet Feynman has no trouble at all with orthodox thermodynamic definitions.
Whacky characters like Denker who want the world to change to their agenda are best avoided.
“Cramped” thermodynamic definitions have saved us from many a “perpetual motion machine”.
Long may it continue!
Apologies to my readers for forgetting to carry over Note 1 from the first article.
It has now been added to this article.
Has anyone worked out roughly what the up and down LW fluxes were during the last ice age? If so, what are they?
Thanks
Is that for global average?
Nitpick: We’re in an ice age now and have been for millions of years. Currently we’re in the interglacial part of the cycle.
The albedo of the planet would be higher during the glacial part of the cycle so there would be less total energy coming in to be dissipated as LW radiation at the top of the atmosphere. The problem is that there is, AFAIK, no data that would allow anything better than a guess for the value of the albedo.
Isotope ratio measurements of sea floor cores give an estimate that the sea surface temperature was about 5 C less than today. If we take that as the planetary average difference then instead of the surface radiating 396 W/m2, it would be ~364 W/m2. If we plug -5 C and 180 ppm CO2 into MODTRAN with the 1976 standard atmosphere holding RH constant and clear sky, the surface sees 231.9 W/m2 compared to 258.7 W/m2 under current conditions.
But that’s as far as I can get without invoking a more complicated model. There needs to be some way of estimating albedo for incoming power and an estimate of convective heat transfer from the surface to the atmosphere to balance the energy budget. Given how little we know and the still crude state of modeling, it’s little better than a guess at this point. The main problem being that the value of the albedo estimated by the model will depend on the climate sensitivity of the model.
Thanks DeWitt, that’s a good and useful answer.
scienceofdoom
Your inappropriate use of the word “heat” causes needless confusion in your posts.
Take some time out and study the Carnot Cycle and find out why it takes extra work to move heat from a lower temperature to a higher one.
Clausius might as well not have bothered as far as you are concerned.
With apologies to regular readers – but there are always new visitors to the blog – Bryan can’t work out:
a) whether radiation from a colder source can be absorbed by a warmer body
b) whether that radiation, if absorbed, can increase the temperature (compared with the case if somehow this radiation was not absorbed)
See Amazing Things we Find in Textbooks – The Real Second Law of Thermodynamics and especially the comments.
Is it true that radiation from a colder source is absorbed by a hotter body? Yes
Is it true that this absorbed radiation can increase the temperature of this body? Yes
The Carnot cycle doesn’t cover these important points. But red herrings are more useful than facing up to Amazing Things we Find in Textbooks, even Non-Cherry Picked Textbooks.
And the Carnot cycle doesn’t cover the Three Body Problem, which is what this is all about.
scienceofdoom
You cannot cope with the Carnot Cycle which gives the most efficient(ideal) way of transferring Heat from a colder to a warmer body.
This underpins the second law of thermodynamics.
However here’s an even easier proof that you have strayed well outside the framework of Physics.
Use your rather good graphing facilities to produce a graph of temperature against wavelength for the same black body radiating at;
600K
900K
1200K
Superimpose all three on one graph.
Once we are looking at the same graph I feel it will be easy to prove to you that a cold body cannot increase the temperature of a hotter body.
“Use your rather good graphing facilities to produce a graph of temperature against wavelength for the same black body radiating at;
600K
900K
1200K”
I don’t get it. Plot temperature against wavelength? That will be a straight line — each of the three blackbodies only has one temperature.
Maybe you mean to just plot the traditional blackbody radiation curve (spectral radiant exitance against wavelength)?
I suspect that Dr/Mr/Ms/Prof Science of Doom is perfectly aware of the shape of that curve. What are you expecting to be learned from it? There’s no particular relevance to the topic that I can see.
“a) whether radiation from a colder source can be absorbed by a warmer body”
You’ve gone to great lengths to repeatedly show this is true. And then completely ignored the fact that in the specific instance of the ocean there is no mechanism for it to happen at anything other than the top few molecules.
Why persist with this fallacy that back radiation heats the ocean when it can only slow its cooling rate. ITS IMPORTANT! Because the only way for the ocean to gain energy is through direct sunlight and thinking otherwise is sloppy and going to cause misunderstandings for many.
As an example of how one might be unstuck with this way of thinking is if you think of it as heating then its a constant “input” of energy into the ocean. However reality has its effect change as a function of the temperature of the ocean which I dont think is intuitively appreciated when thought of as radiatively “heating”.
Ned
…..”.Maybe you mean to just plot the traditional blackbody radiation curve (spectral radiant exitance against wavelength)?.”……
Yes what other meaning could there possibly be for the three quoted temperatures
……”There’s no particular relevance to the topic that I can see.”…….
If you pay attention you will see the relevance relative to the title of this thread.
Yes what other meaning could there possibly be
Well, it didn’t make much sense, but IMHO a lot of what you write here doesn’t make much sense, so I wasn’t sure.
If you pay attention you will see the relevance relative to the title of this thread.
OK. I am paying attention. The title of the thread is “Does Back Radiation “Heat” the Ocean? – Part Three”. I’m now visualizing three nested blackbody radiation curves, at 600, 900, and 1200 K, though I can’t readily draw them in this comment box.
The relevance still escapes me.
Er, make that “IMHO a lot of what you write here doesn’t make much sense to me“ … I’m sure it makes sense to you.
Ned
Well Ned, as you are a believer in GAGW on the basis of the trace gas CO2 you must have an active imagination.
Perhaps SoD will put up the graphs so that any less imaginative reader can see whet follows.
Nothing less than the demonstration for once and for all, that heat does not move spontaneously from a colder to a hotter body.
In the meantime why don’t you have a look at the Carnot Cycle which makes much the same point.
Bryan:
I don’t know what “GAGW” is, though I’m guessing it’s something about “anthropogenic global warming.”
While I am not sure about your claimed causality, I do have a good imagination. Thanks for the compliment.
I understand very well that heat does not move spontaneously from a colder to a hotter body. Given the wording of Note 1 (added Dec 6th) at the end of the post here, I think that Science of Doom also understands that perfectly well.
I also agree with the conclusion of that note (“It is a dull point”) and will be a bit disappointed if that’s all you’re saying here, since that would just be repeating the obvious.
Perhaps, instead of arguing, we could all try to find some common ground. For example, I would agree with both of the following statements:
(1) Heat does not flow spontaneously from the cooler atmosphere to the warmer ocean.
(2) A warm ocean will absorb more radiation from a slightly cooler atmosphere than from a much colder atmosphere.
Can you also agree with both those statements?
Bryan has just proved that a trace gas cannot have an influence on the atmosphere, henceforth a trace substance cannot have influence on a human.
10 mg Polonium cannot kill a grown human of 80kg because the Polonium would translate to approx 8ppm, that’s a trace substance. Even more a trace substance then CO2 is a trace gas in the atmosphere. Also the Polonium cannot kill a grown human because water makes up about 80% of our bodies and water is not affected in any way by Polonium.
A less imaginative reader can easily see it’s much more likely that the ex-Russian spy died from lack of water or too much water, but it is impossible to die from Polonium poisoning. The same is also true for Arsenic. Anyone who believes those substances can kill a human must have an active imagination.
Why? Because I say so and just look at some bacteria which makes much the same point…
cynicus
We must examine like for like.
It would be wrong also to conclude that trace amounts always produce big effects.
For instance lets say that CO2 did not radiate in the IR.
I don’t think the climate would change much.
Ned is correct.
Bryan probably has a very short memory to say: “Nothing less than the demonstration for once and for all, that heat does not move spontaneously from a colder to a hotter body”
We all agree on this. Bryan imagines we don’t.
Perhaps I should link to the last 10 interactions with Bryan where I say “more energy flows from the hotter to the colder than from the colder to the hotter – and therefore net heat is from the hotter to the colder”.
For new readers to this blog who are uncertain about whether energy from a colder body can also be absorbed by a warmer body.
The strongest advocate (on this blog) against this simple idea has to rely to pressing the reset button each time and “forgetting” the actual questions asked of him.
Perhaps this might help new readers realize how weak the arguments against this simple idea are. Take a look at the textbook link from the comment above as a starting point.
Thanks. As a very infrequent (?) commenter here, I should add that I very much enjoy reading your posts. You have a great deal of patience, and a very clear way of explaining things. I try to emulate those qualities on another site where I’m a more frequent commenter/blogger, so I am acutely aware of how much effort it takes.
Bryan,
Heat has a variety of definitions and even in thermodynamics it can mean different things in different contexts. It’s not like, as you listed on another thread, frequency. SoD did put the term in quotes in the title of this thread. This isn’t a college level physics or chemistry course. Insisting that your definition is the only true and correct definition is more than a tad pedantic.
Medhurst:
I never imagined I would have to go to such lengths. The threads and articles are only heavily biased in this direction because of the frequent claims of people (like Bryan) that it can’t happen. Mostly by not answering the actual point but by use of the Carnot defence:
This tends to distort any real discussion but is an unfortunate necessity.
You said “And then completely ignored the fact that in the specific instance of the ocean there is no mechanism for it to happen at anything other than the top few molecules.”
What this article is about is demonstrating how the heat in the top millimeter of the ocean DOES become well-mixed with the next few meters down.
Then you said: “Why persist with this fallacy that back radiation heats the ocean when it can only slow its cooling rate. ” – which in fact is exactly what I am saying. If more energy arrives via radiation in the top millimeter of the ocean it slows down the cooling. This means that more heat is retained in the ocean as a result of more back radiation.
The title of the article has “heat” in quotes for specifically this reason. See note 1.
However, given the two statements of yours I have restated I am unsure of what you are actually claiming.
In the next article we will look at how heat actually moves between:
– the ocean mixed layer
– the ocean surface
– and the atmosphere
via the various mechanisms. And how back radiation changes these relationships.
“What this article is about is demonstrating how the heat in the top millimeter of the ocean DOES become well-mixed with the next few meters down.”
No it doesn’t. Look closely at the top millimeter and look at where the DLR effects the skin temperature.
What all your references refer to are that mixed water (due to wind primarily) distributes the energy (unspecified but actually from the shortwave suns rays) deeper than when there is no wind. Nothing more and certainly not that the cold skin heats the bulk.
The skin is cold. Its colder than the bulk and so once again when its mixed down its a coolling effect not one of warming. The point is that increased DLR may slightly increase the skin temperature (ala Minnett) and so cool less.
But its still a slower cooling effect and not a warming effect.
This is fundamental to the thinking and you MUST make it clear whats happening before you can move on with any arguments that build on this.
SoD,
There is rather a large difference between the top few microns and the top millimeter of ocean. I read somewhere that in fact the top few mm of ocean surface is on the order of a third of a degree cooler than the water beneath it due to evaporation.
I look forward to Part Four.
scienceofdoom says
“more energy flows from the hotter to the colder than from the colder to the hotter – and therefore net heat is from the hotter to the colder”.
This is not correct.
This implies more heat goes from hot to cold and less heat from cold to hot.
The point is NO HEAT goes from cold to hot.
Lets see what Professor Claudius says;
Rudolph Clausius (1822-1888) Germany
Heat cannot of itself pass from a colder to a hotter body.
It is impossible to carry out a cyclic process using an engine connected to two heat reservoirs that will have as its only effect the transfer of a quantity of heat from the low-temperature reservoir to the high-temperature reservoir. (1854?)
“Es existiert keine zyklisch arbeitende Maschine, deren einzige Wirkung Wärmetransport von einem kühleren zu einem wärmeren Reservoir ist.”
It does not exist, a cyclically operating machine, whose only effect is heat transport from a cooler to a warmer reservoir.
It is impossible for a self-acting machine, unaided by any external agency, to convey heat from one body to another at a higher temperature. [kelvin’s translation]
Do you get the point scienceofdoom?
Its not that heat mostly travels from hot to cold as you seem to think.
I am coming to the conclusion that a study of the Carnot Cycle should be compulsory for all Climate Science degree courses.
Perhaps that is the only way to end the confusion over the direction of heat flow.
Bryan, I am getting the impression that the only thing you object to is the way the word “heat” is used. Am I correct in thinking that you don’t disagree with the actual process described in this post? In other words, as I asked above, can we all agree that a warm ocean will absorb more radiation from a slightly cooler atmosphere than from a much colder atmosphere?
I think that is the real point here. Consider the following two cases:
Case A: A planet with a lower concentration of greenhouse gases in its atmosphere.
Case B: The same planet, but with a higher concentration of greenhouse gases.
My understanding is as follows:
(1) All else being equal, greenhouse gases make the atmosphere warmer in Case B than it would be in Case A.
(2) This warming of the atmosphere increases the magnitude of the flux of longwave infrared radiation from the atmosphere to the ocean in Case B. This magnitude is still smaller than the flux moving in the opposite direction (from the ocean to the atmosphere) but it is larger than it would be in Case A.
(3) This increased downward longwave radiation flux in Case B keeps the ocean warmer than it would be in Case A.
That seems very straightforward to me, and there is no violation of any of the laws of thermodynamics. Do you agree?
Answering that question seems like it would be much more productive in furthering the discussion than continually shouting at the host for not understanding something that he actually understands perfectly well.
Medhurst:
To try to answer your questions, I need to understand one point. To ensure I understand your real question/issue.
A slower cooling effect is a warming effect.
If less cooling – then the temperature will be higher. Do you agree?
“A slower cooling effect is a warming effect.”
No I do not agree. A slower cooling effect is a slower cooling effect and a warming effect is a warming effect.
It is far too easy to fall into the trap thinking DLR can raise the ocean temperature…but it cant. This concept must be crystal clear to go on to discuss increased CO2 effects on OHC.
Medhurst: No I do not agree. A slower cooling effect is a slower cooling effect and a warming effect is a warming effect.
Consider two oceans, one with a slower cooling effect and one with a faster cooling effect. Will the first be warmer than the second?
Or is there some problem with the word “warm” that makes it very, very important that we not use it at all when talking about the greenhouse effect?
“Consider two oceans, one with a slower cooling effect and one with a faster cooling effect. Will the first be warmer than the second?”
You miss the point. Consider two oceans, one with a slower cooling effect (for example some DLR) and one with an equivalent warming effect (for example widespread undersea geothermal activity)
Now imagine they’re in the Arctic and its Winter with no incoming shortwave radiation. How does each react now?
Its an important distinction to keep in mind when considering how they will react to other forcings.
Ned
…..”Bryan, I am getting the impression that the only thing you object to is the way the word “heat” is used. “…..
To be perfectly frank I was not prepared to read the article further if the author was confused about the direction of heat flow.
Whats the point!
This is a major source of disagreement between myself and SoD.
It might be the case that he is making some interesting points and on occasion he might even get the correct flow of heat.
He devalues the rest of the article by this fundamental mistake.
People on SoDs side the AGW debate should suggest that he stops this ambiguity rather than encourage him to continue with the muddle.
Reduced cooling is not heating.
But the author is not confused about the direction of heat flow. Everyone here knows that Sci.Doom knows that the longwave radiative flux from the warmer ocean to the cooler atmosphere is larger than the flux in the opposite direction.
Insofar as the use of the word “heat” is “a major source of disagreement” between yourself and SoD, it is quite obviously because you continually choose to misunderstand SoD. It appears that you actively want the discussion to remain focused on terminology, rather than moving on to matters of substance.
This is all rather curious. Let’s assume that the radiative exchanges between the sun, the ocean, and the atmosphere are all balanced, as follows:
(1) The sun emits a steady flux of shortwave radiation, which is absorbed by the ocean.
(2) The ocean emits a steady flux of longwave radiation, which is absorbed by the atmosphere.
(3) The atmosphere emits a steady flux of longwave radiation, part of which is absorbed by the ocean and part of which is dissipated in outer space.
All radiation fluxes are constant over time, and the temperatures of the sun, the ocean, and the atmosphere are constant over time.
In other words, the ocean’s temperature is stable. It is neither becoming warmer nor becoming cooler. Does anyone object to this characterization?
OK, now assume the temperature of the atmosphere is increased, perhaps by an increase in the concentration of greenhouse gases or perhaps by some other means. The downward flux of longwave radiation from the atmosphere to the ocean has increased.
This means that the ocean’s temperature, which was previously stable, is now increasing (per the mechanisms discussed in this post).
When a process results in the previously-stable temperature of the ocean suddenly starting to increase, I think most people would describe that change as “warming”.
But apparently, it is very, very important to Bryan that we all must describe this increasing temperature as “reduced cooling”.
Likewise, Medhurst is very, very insistent that we all must describe this increasing temperature as “a slower cooling effect.”
IMHO, George Orwell is smiling wryly from whatever afterlife he is now experiencing.
Ned,
The same mistake that you and SOD keep making is the claim that the (average) back radiation would be the cause of a warmer ocean than otherwise.
The increase of greenhouse gases would raise the location of outgoing radiation to space, and thus lock the location in the atmosphere where the temperature is (average) 255 C. The convection maintaining the adiabatic lapse rate would be the source of the increased ground (and ocean) temperature. The increased ground and ocean temperature would then be the CAUSE of increase forward and back radiation. The radiation is not the cause of the temperature increase but the effect! That is the basis for most of this disagreement and discussion. I do think the increased greenhouse gas would cause a temperature increase, but the amount would depend mostly on the level of feedback, and I think it would be small for a CO2 doubling.
As an aside, there are cases where back radiation can heat the ocean. This is when the air temperature or clouds above the ocean are warmer than the ocean. Wind and ocean currents, night and day and different latitudes, and different cloud condition may make this possible locally. The largest cause would be during spring, when thermal lag causes the ocean to warm slower than the air. However, these are not the long term (yearly) average conditions I am talking about.
Case A: A planet with a lower concentration of greenhouse gases in its atmosphere.
Case B: The same planet, but with a higher concentration of greenhouse gases.
My understanding is as follows:
(1) All else being equal, greenhouse gases make the atmosphere warmer in Case B than it would be in Case A.
(2) This warming of the atmosphere increases the magnitude of the flux of longwave infrared radiation from the atmosphere to the ocean in Case B. This magnitude is still smaller than the flux moving in the opposite direction (from the ocean to the atmosphere) but it is larger than it would be in Case A.
I don’t have any problems with your formulation.
I would express the situation as possible.
For instance the greenhouse gases could also intercept incoming radiation and act as a coolant.
It appears however from the experiment by Wood that the greenhouse effect is not particularly strong.
Ah, excellent. Thank you, Bryan.
It seems we’re all on the same page, as far as general principles go. There is always a flow of heat from the warmer ocean to the cooler atmosphere, even in the standard formulation of the greenhouse effect.
As a side note, this nicely removes from the table the claim (not necessarily made by any one in this thread) that the greenhouse effect somehow would violate the second law of thermodynamics. Clearly, there is no such violation as the GHE is discussed here.
As a further side note, accepting that the GHE does not violate the second law does not imply that climate sensitivity is high, that IPCC temperature projections are accurate, or that the anticipated costs of 21st century GHE-induced climate change are severe enough to necessitate any particular mitigation.
I will be the first to agree that it is absolutely OK to disagree about those while still accepting that the GHE does not violate any of the laws of thermodynamics.
science of doom,
We seem to be going round and round on the back radiation issue. It is true that there is forward and back radiation at the surface, and that BY ITSELF that would result in the hot surface being hotter. However, the point is that with a convecting atmosphere, the lower atmosphere and surface temperature are determined by the lapse rate and the altitude of outgoing radiation. If the back radiation contribution started to raise the surface temperature above value determined by those causes, the convection would restore it. Please observe the difference of the temperature forcing cause. If you greatly increased the total greenhouse gas effect, you would raise the location in outgoing radiation, and thus raise the surface temperature. However, in the extreme case of near prefect absorption at the surface, the higher forward and back radiations would almost exactly balance, so there would be nearly no net radiation heat transfer. All of the surface temperature would be determined by input solar radiation and convective heat removal. Large radiation levels do not mean the radiation is controlling or even contributing to the surface temperature, they are a RESULT of it.
Medhurst writes:
Consider two oceans, one with a slower cooling effect (for example some DLR) and one with an equivalent warming effect (for example widespread undersea geothermal activity)
Now imagine they’re in the Arctic and its Winter with no incoming shortwave radiation. How does each react now?
That is taking a clear and simple question (mine) and making it more complicated (yours). Normally, this is not the best way to promote understanding. But I am willing to go along.
In your examples, I would say that both oceans are warmed by:
(A) absorption of downwelling solar shortwave radiation
(B) absorption of downwelling longwave radiation from the atmosphere
(C) the geothermal heat flux (if present)
and that both oceans are cooled by:
(D) emission of longwave radiation to the atmosphere.
For both oceans, an increase in A, B, or C, or a decrease in D, would result in an increase in the ocean’s temperature. Likewise, for both oceans, a change in the opposite direction would decrease the ocean’s temperature.
In normal conversation, I would be comfortable describing the process that led to an increase in the temperature of the ocean as “warming the ocean.”
Thus, I would say that the greenhouse effect “warms the ocean” rather than that it “reduces the cooling of the ocean” because, if you start at equilibrium and don’t simultaneously alter other forcings, increasing the concentration of greenhouse gases would warm (increase the temperature of) the ocean.
Now, in Medhurst’s formulation, we are specifically asked to assume that the ocean’s temperature is actually decreasing, because of a reduction in A (shortwave insolation). Would that change how we talk about A, B, C, or D?
No, I don’t think so. I would still say that the ocean is being warmed by A, B, and C, and that it’s being cooled by D. I would also say that the process causing the decrease in A was “cooling the ocean” even though A itself warms the ocean.
“That is taking a clear and simple question (mine) and making it more complicated (yours). ”
Your example had nothing to do with reduced cooling vs warming and the distinction between each. Your example was reduced cooling vs reduced cooling. Not very useful.
You didn’t answer the question though. How does each ocean react to the conditions I specified?
If you can see the difference, then you’ll understand why reduced cooling is different to warming and why they need to be considered correctly.
The conditions you specified were a reduction in shortwave solar insolation.
Reducing insolation means that the ocean absorbs less shortwave radiation. If all else is equal, this will tend to lower the temperature of the ocean.
Thus, a process that results in a reduction of insolation would best be described as “cooling” the ocean.
This applies equally to both of the oceans in your example.
You’re still avoiding answering the question and thereby acknowledging that there is very definitely a difference between reduced cooling and actual heating.
I’ll answer it for you then you can dispute it if you want.
For suitable choices of timeframes and magitudes of heating (ie amount of GHG forcing vs amount of geothermal activity carefully chosen to be the right magnitude but equal in size) the GHG forcing (ie reduced cooling) ocean will eventually freeze. However the heat added by geothermal activity will stop the ocean from freezing.
Big difference.
I find it rather ironic that you claim I’m “avoiding answering the question”.
In my comment upthread at 12:28 pm, I asked you the following question:
Consider two oceans, one with a slower cooling effect and one with a faster cooling effect. Will the first be warmer than the second?
You still haven’t answered that.
Instead, you asked me how a pair of oceans would respond to a reduction in insolation. I answered that in detail (the 2:17 pm comment).
You then asked the same question again. I answered it somewhat differently in my 3:24 pm comment.
You may not like my answers. But I’ve tried to answer your questions. In contrast, you still won’t answer mine:
Consider two oceans, one with a slower cooling effect and one with a faster cooling effect. Will the first be warmer than the second?
It seems like a very easy question to answer. If you don’t want to answer it, how about one of these:
Is it acceptable to say that the onset of winter cools the ocean (by reducing the amount of sunlight it absorbs)? Or do we have to say that winter causes a slower warming of the ocean?
Suppose the Yellowstone supervolcano erupted tomorrow, ejecting vast quantities of aerosols into the stratosphere and cutting insolation to the point where the global mean temperature dropped 2 C in a matter of weeks. Would it be acceptable to say that the volcanic eruption cooled the planet, or would we have to say that it reduced the warming of the planet?
“Consider two oceans, one with a slower cooling effect and one with a faster cooling effect. Will the first be warmer than the second?
It seems like a very easy question to answer. If you don’t want to answer it, how about one of these:”
I didn’t bother answering because I thought it was a rhetorical question. I think we can assume we all have some idea of how thermodynamics works here and your answer is entirely obvious.
Now…how does this relate to a discussion of reduced cooling vs warming?
OK, I’ll assume that means “yes”. In other words, I take it we’re agreed that a process that reduces the cooling of the ocean makes the ocean warmer than it would be if that process were weaker or absent.
With that established, let’s revisit your remarks that started this all off:
The point is that increased DLR may slightly increase the skin temperature […] But its still a slower cooling effect and not a warming effect.
This is fundamental to the thinking and you MUST make it clear whats happening before you can move on with any arguments that build on this.
I think that’s entirely wrong. Far from being “fundamental”, I think the distinction you are emphasizing is mostly or entirely semantic, with little to no meaningful information content.
We could say that “the onset of winter reduces the warming of the ocean” but most of us would instead say “the onset of winter cools the ocean” even though what’s actually occurring is a reduction in the solar radiation that warms the ocean.
Of course, the case we’re discussing here (downwelling longwave radiation) is even more straightforward. There is no reason at all to call it “a slower cooling effect” as you did in your first comment. That really makes no sense at all. The ocean absorbs longwave radiation … how could this make it cooler? The absorption of downwelling longwave radiation warms whatever surface is absorbing the radiation.
IMHO, it’s silly to demand that people distinguish between “an effect that slows/reduces cooling” and “an effect that warms” — particularly when nobody bothers making that distinction in the opposite direction (nobody ever objected to the statement that the reduced insolation in winter “cools” the ocean).
And even if there were value in strict enforcement of that semantic distinction, it wouldn’t apply to downwelling longwave radiation anyway. We’re talking about absorption of photons. If you insist on distinguishing between “reduced cooling” and “warming”, anything that increases the absorption of photons would fall on the “warming” side of that semantic divide.
Or so it seems to me. I don’t speak for Sci.Doom, or anyone else here.
” There is no reason at all to call it “a slower cooling effect” as you did in your first comment. That really makes no sense at all. The ocean absorbs longwave radiation … how could this make it cooler? The absorption of downwelling longwave radiation warms whatever surface is absorbing the radiation. ”
It is precisely because of misunderstandings like this one that we need to make sure we understand the process precisely.
Saying DLR warms the ocean is like saying a thermos warms coffee. It just doesn’t.
Would the ocean be cooler without DLR? Yes of course but from your comments it looks very much like the mechanism isn’t what you believe it is.
Ned
…..”I will be the first to agree that it is absolutely OK to disagree about those while still accepting that the GHE does not violate any of the laws of thermodynamics”
….
Yes I agree that a rational discussion is the only way to further understanding.
However some versions of the “greenhouse effect” are impossible.
The main failing of some of these ” theories” is to suggest that heat is moving from a colder atmosphere to a warmer Earth Surface thus implying a violation of the second law.
Some others violate the first law.
Some others fail for other reasons and some fail all the above.
As far as I know there is no Orthodox Greenhouse Effect which the vast majority of adherents subscribe to.
Bryan writes: The main failing of some of these ” theories” is to suggest that heat is moving from a colder atmosphere to a warmer Earth Surface thus implying a violation of the second law.
I have never seen a model of the greenhouse effect that involved actually moving heat from the cooler atmosphere to the warmer surface. Certainly, nothing discussed on this site involves that.
As long as the model correctly has a larger flux from the surface to the atmosphere than the opposite, there is no violation of the second law.
Sci.Doom (or someone else) choosing to describe such a correct model by saying that radiation from the atmosphere “warms” or “heats” the surface does not mean that the model itself violates the second law.
Some others violate the first law.
Some others fail for other reasons and some fail all the above.
That’s not very informative.
More to the point, the (hypothetical) existence of other people’s mistaken theories of the greenhouse effect doesn’t really have any bearing on whether the standard model of the greenhouse effect is wrong.
The standard model clearly doesn’t involve a second-law-violating flow of heat from cold to warm. Of course, it could fail due to one of your other cryptic reasons (violating the first law or some unspecified “other reason”) but you haven’t shown that.
Ned
….”Sci.Doom (or someone else) choosing to describe such a correct model by saying that radiation from the atmosphere “warms” or “heats” the surface does not mean that the model itself violates the second law.”…..
I agree that careful use of words like” heat” could avoid needless confusion.
Is the “standard model” the Orthodox Greenhouse Effect?
Where can I get a copy?
…..”Of course, it could fail due to one of your other cryptic reasons (violating the first law or some unspecified “other reason”) but you haven’t shown that.”……
Gerhard Gerlich and Ralf Tscheuschner produced a famous peer reviewed paper listing the main greenhouse theories current in 2008
Is the “standard model” the Orthodox Greenhouse Effect?
Where can I get a copy?
There is no single written document that embodies the standard model of the greenhouse effect.
There is likewise no single written document that embodies the standard model of plate tectonics, or of biological evolution.
In all three cases (GHE, plate tectonics, and evolution) there are papers, reports, books, etc. that discuss individual components in great detail, and/or broad outlines in lesser detail.
If you want to learn more about the greenhouse effect, the following website provides an excellent review of the current scientific understanding of this interesting phenomenon:
http://scienceofdoom.com
As a bonus, on that site there’s also a fair amount of discussion of the problems in G&T 2008.
Ned
….”As a bonus, on that site there’s also a fair amount of discussion of the problems in G&T 2008″……
Yes I was involved in some of the discussions.
I cleared up some of the misplaced criticism’s such as
‘G&T say that a hot body cannot radiate to a colder body’ kind of thing.
I encouraged folk to actually READ the paper and most find that it is a helpful contribution to the climate debate.
should read
I cleared up some of the misplaced criticism’s such as
‘G&T say that a cold body cannot radiate to a hotter body’ kind of thing.
Bryan,
G&T is not helpful to anything other than decreasing respect for the authors. I have read the paper by the way. From your posts here, I conclude that you like G&T because the authors persist in willfully misunderstanding the science and concentrating instead on semantics (see all of Section 3, particularly 3.7.2).
The section I find either most pathetic or most hilarious is 4.2 The conservation laws of magnetohydrodynamics. There is much ado about the inability to solve the Navier-Stokes equations. Everyone is quite aware of this. There is even a Millenium Prize offered for progress in this area. Then the assertion is made that the problem is too complex so that no valid approximation is even possible. That’s a surprising statement for physicists to make. There is no analytical solution to the inverse problem of turning an x-ray diffractogram into a crystal structure. Yet it’s done every day. There’s also numerical weather forecasting. The core of those programs involve approximate solutions to Navier-Stokes. Sure they break down after a few days, but it’s clear that there is some validity to the solution method. I don’t know G&T’s opinions on string theory, but there are no unique solutions to those equations either.
But the topper comes when they make this statement:
What evidence? The references are to texts on MHD and Astrophysics. MHD would indeed be quite important in a stellar atmosphere. What it has to do with our atmosphere is far less clear. Then there’s a lot of irrelevant math followed by this statement:
It’s hard to avoid either laughing out loud or screaming obscenities about the authors’ habits when reading something that stupid.
The Carnot cycle defines the maximum amount of work that can be extracted using a heat engine from two reservoirs of infinite heat capacity (compared to the work done) at temperatures T1 and T2 where T1 ≠ T2 and the process is carried out reversibly, i.e. infinitely slowly. While there are process like hurricanes and thunderstorms which can be described as heat engines, by and large work done in the atmosphere is an infinitesimal fraction of the total energy flow and is irrelevant to understanding the greenhouse effect.
DeWitt Payne
Your reply contains a surprising amount of vitriol.
To an impartial observer your suggestions that two theoretical physicists don’t know any physics is absurd.
……”willfully misunderstanding the science and concentrating instead on semantics”……
The direction of heat flow is not semantics (review your comments above)
Your only specific attack comes in this section;
……”The section I find either most pathetic or most hilarious is 4.2 The conservation laws of magnetohydrodynamics.”..
….”Evidently, the electromagnetic interactions have to be included, leading straightly to the discipline of Magnetohydrodynamics (MHD) [188-191].”…..
the equations of magnetohydrodynamics and in particular electrodynamics are relevant to the description of clouds, thunder and lightning, electromagnetic radiation and the dielectric properties of the components of the atmosphere including the “killer” CO2.
Increasing emphasis is being placed on SUNSPOT activity and cosmic ray interactions as being a major driver of climate.
So I find your hilarity entirely misplaced.
Again you seem to be highly amused by their request for CO2 concentration information
….”There is no term that depends on the carbon dioxide concentration.”…..
However in the IPCC proposed “CO2 greenhouse theory” you would expect that this should figure prominently.
….”The Carnot cycle defines the maximum amount of work”…….
The Carnot cycle also addresses the problem of heat transfer from a lower temperature to a higher temperature.
This is a problem that SoD seems obsessed with.
Straight out of the Carnot Analysis comes the famous Second Law which is a major obstacle to crackpots.
I notice that your “uncramped” thermodynamics expert John Denker failed to include the Carnot analysis.
Denker is a big fan of Feynman and quotes him often.
However Feynman like any competent physisist has no trouble with orthodox thermodynamic terms.
When Feynman finished his thermodynamics sections in the famous 3 volume lectures he recommended interested readers who wanted to take the matter further only one book.
The book he recommended was the ultra orthodox Heat and Thermodynamics by Zamansky.
Your apparently think that the Carnot analysis is only relevant to someone interested in ideal engines.
…..”and is irrelevant to understanding the greenhouse effect.”…….
In every Physics textbook that I have come across the Carnot analysis is used to introduce and explain the second law but perhaps you think this is only semantics.
Reread your notes on Clausius and the Second Law as I think that aspect has escaped you.
Bryan, as always, extols the operatic paper of Gerlich and Tscheuschner:
No, they listed some ideas from 100 years ago and some later encyclopedia references.
They failed to comment on Manabe & Wetherald 1967, they failed to comment on Ramanathan & Coakley 1978.
As the subtitle from On the Miseducation of the Uninformed indicates: “The Modern Solution to the RTE – or How to Miss an Important 100 Years“:
Of course, I’m quoting from my own comments.
It would be wonderful to see Gerlich or Tscheuschner here on the blog to try and defend their indefensible.
I know it won’t happen because it’s indefensible. They only really have Bryan on their side.
Well, Bryan asks a good question but won’t pay attention to the answer:
I can’t speak for the general public but I am confident that Ramanathan & Coakley 1978 is fully accepted in the climate science community.
Also for a more complete explanation, the textbook: “Atmospheric Radiation: Theoretical Basis” by RM Goody & YL Yung, 2nd edition (1989).
Or you could try any atmospheric physics textbook in a university library near you.
Value for money I recommend “Elementary Climate Physics” by Professor F.W. Taylor of Oxford University. Try .bookdepository.co.uk for just over $40 with free shipping.
I would look forward to your explanation of the flaws in any of these – or your endorsement – but past experience prevents me from experiencing too much optimism.
Instead I expect the same question in about 6 weeks.
I only write this comment as a service to other readers.
scienceofdoom
……”No, they listed some ideas from 100 years ago and some later encyclopedia references.”…….
Yes its true that Clausius and Carnot and others established the basis of our understanding of thermodynamics over 100 years ago.
Yet Feynman and Einstein found them quite acceptable.
What is regrettable is that some recent contributions to this site have either forgotten or ignore them.
SoD tell me of some findings since then that make them invalid?
You list a number of books that you claim to have read but which one in particular led you to think that;
……some heat flows from a colder object to a hotter one..?
I said to Ned
As far as I know there is no Orthodox Greenhouse Effect which the vast majority of adherents subscribe to.
He replied
There is no single written document that embodies the standard model of the greenhouse effect.
Gerlich and Tscheuschner write from the mainstream of physics.
Their methods and analysis are straightforward, paying attention to experimental evidence such as the R W Wood experiment and a high level of mathematical competence.
I have yet to find anyone that has rendered any of their points invalid.
I realise that if yourself and the Halpern group had the power you would have had it banned.
Censorship has stifled open debate in the area of climate science.
What are you so frightened of.
You don’t have to agree with every point to see it as a valid and useful contribution to the climate debate.
Bryan writes: I said to Ned
As far as I know there is no Orthodox Greenhouse Effect which the vast majority of adherents subscribe to.
He replied
There is no single written document that embodies the standard model of the greenhouse effect.
That’s not quite correct. My reply was to your snarky comment:
Is the “standard model” the Orthodox Greenhouse Effect?
Where can I get a copy?
I then pointed out that one can also not “get a copy of” “The Orthodox Plate Tectonics Effect”, nor of “The Orthodox Biological Evolution Effect”.
I thought you understood the point, but since you’re bringing this up again, maybe you didn’t.
Finally, I noted that the absence of an inerrant scripture does not mean that scientists working in plate tectonics or whatever don’t share a common understanding of the major concepts and processes. These common understandings are recorded in papers, conference presentations, textbooks, etc.
This is the way science works. If you want scripture, go to religion. (No disrespect intended to either religion or science.)
Bryan writes: I realise that if yourself and the Halpern group had the power you would have had it banned.
This is a revealing comment indeed, but it says much more about you than about either Science of Doom or G&T.
Ned
All those mentioned are on record as saying the G&T paper should never have been published.
This is a bit rich coming from the folk who think the Mann “Hockey Stick” paper is serious science.
All G&T said is that there is no evidence that the radiative properties of CO2 are a cause for public alarm.
WUWT today point out that a growing number of prominent scientists agree and some go further and call the CO2 greenhouse theory a fraudulent scam.
Bryan, your comments seem to have less and less to offer as time goes by. Most of the people I know who like this site appreciate it specifically for the calm, rational focus on the science … and the absence of endless chest-beating about Mann, hockey sticks, WUWT, “fraudulent scams”, and whatnot.
As an aside, there’s a difference between saying that something should never have been published and saying that something should be banned.
I think Star Wars: The Phantom Menace should never have been filmed. I don’t think it should be banned.
Do you understand the distinction? Hint: it involves judgment.
Again, your comment says more about you than about Science of Doom, the authors of Halpern et al., or G&T for that matter.
Ned
Is this your idea of
calm, rational focus on the science
“My reply was to your snarky comment:”
I thanked SoD for what appears to be a coherent account of the consensus view of climate science.
It will take me some time before I can comment further on it.
All the above wrote to the publishers of the G&T paper in the most intemperate way.
Had any of them been in a position to stop publication I’m pretty sure of their response.
scienceofdoom
….”I can’t speak for the general public but I am confident that Ramanathan & Coakley 1978 is fully accepted in the climate science community.”……
Downloaded the paper and it seems to cover all major areas;
Will read and use it in the future as the orthodox theory.
Thanks.
Bryan,
I’ll ask this again:
In section 3.7.2 of G&T they make the statement:
Please explain to me how this is not willful ignorance. The numbers for radiation are obviously fluxes integrated over a hemisphere, hence the arrows indicating the perpendicular to the plane of the hemisphere. For convection, the arrows indicate the direction of net heat flow. These fluxes are not theoretical constructs. They can be measured. If G&T had done their homework they would have known this.
The title of the section is A note on “radiation balance” diagrams. But it is actually the core of the paper. If they are wrong about this, then they have not falsified the greenhouse effect. And they are wrong.
It looks like irradiance is the correct terminology for incident radiation (arrow toward the surface) and radiant emittance for emission (arrow toward space). This isn’t exactly rocket science.
Oh, and it’s bile, not vitriol. Reading G&T gives me indigestion.
G&T provide 4 different possible interpretations for these diagrams.
They find that all four fail to explain their physical significance.
There is no law of conservation of radiation as these diagrams seem to imply.
The inverse square law is involved for your interpretation irradiance.
The particular diagram fig 23 has no units shown which doesn’t help.
Are we taking of a vector quantity or a scalar?
Who knows?
The diagrams I think are a broad brush effort to convey in a pictorial way some kind of climate information.
They perhaps were never intended to be used as an accurate description of the real world.
Bryan
What would be much much better is to explain what’s wrong with it.
If you can’t find anything wrong with it then perhaps the radiative-convective model of the atmosphere is a theory for you to embrace.
scienceofdoom
Give me a chance to read the paper.
One thing I did notice was the paper makes several references to the work of Chandrasekhar.
G&T also rate him highly.
So at least there is some common ground.
Bryan,
Let’s change the terms of the debate. Suppose the title of this post was: Does Back Radiation Increase the Energy Content of the Ocean? We’ll also just look at final states, and not the path to the states. Suppose we have an ocean that sees X W/m2 back radiation and Y W/m2 incident solar radiation. Allow sufficient time to achieve steady state. We’ll call the energy content of the ocean Q. If the back radiation is increased to X + ΔX and nothing else changes, the ocean heat content will be Q’. Will Q’ be greater than, less than or equal to Q and why.
Regarding : “Does Back Radiation Increase the Energy Content of the Ocean?”
…and your setup of the conditions… then “Will Q’ be greater than, less than or equal to Q and why.”
Under the conditions you’ve specified, Q’ is greater than Q because the new equilibrium established must involve a greater SST to maintain the same net energy loss from the ocean. ALL other things being equal.
Add one more variable, evaporation. Simply enable it in the above conditions.
Now what can you say about Q’ vs Q?
Q’ will still be greater than Q, but not by as much. For evaporation to increase, the SST must be higher than the original temperature.
“For evaporation to increase, the SST must be higher than the original temperature.”
Are you certain about that?
Evaporation is itself a cooling effect. Additional DLR must increase evaporation because its effect is on those very molecules that are evaporating…and that increased DLR effect is independent of SST.
Perhaps you could clarify why the SST must be higher or where my reasoning fails?
Medhurst,
Think of evaporation as a negative feedback. Unless you get 100% negative feedback, which is not likely in the real world, any increase in forcing will result in some increase in heat content and temperature. The increase will be less than with zero negative feedback, but it won’t be zero. Or think of it this way, if the rate of evaporation is not proportional in some way to temperature, what constrains its value?
Evaporation is proportional to the amount of energy available. A boiling pot will evaporate faster if its turned up vs turned down to “just boiling”
Hence the amount of ocean evaporation is proportional DLR as well as SST and the way I see it, increased SST is not necessary if increased evaporation is what the energy is used for.
Now I am not actually saying there will be no OHC increase in practice. You may well be right …but what I’m really doing is pointing out that with a single variable added into consideration, suddenly its no longer obviously inevitable OHC increases with increased DLR.
There are many more variables to be added as well…
The temperature of boiling water is held nearly constant by the phase change so it’s irrelevant to the problem at hand. At normal sea surface temperature the vapor pressure is changing exponentially with temperature. It is very unlikely that an increase in energy input would result in nothing but an increase in evaporation. Increased evaporation without a temperature increase would require some combination of lower relative humidity and higher average wind speed. That requires specifying a mechanism or mechanisms that would produce those conditions or citing a relevant example where that occurs. Good luck with that.
More about the basics of water vapor and evaporation in Clouds and Water Vapor – Part Two.
DeWitt Payne
…….”some combination of lower relative humidity and higher average wind speed”…….
Very simple experiments show how effective wind speed is at increasing evaporation, hence cooling the liquid surface.
Blowing on a spoonful of hot soup comes to mind.
The fact that 70% of the Earth surface can show dramatic changes, to a frankly chaotic variable as wind strength, might explain why models of the Earths climate seem doomed to fail.
Bryan,
Heat transfer from the surface to the atmosphere is not a free variable that can take on any value. For a given energy balance and temperature distribution, if more energy transfer on average by evaporation (and less by radiation) were possible, it would have already happened. Latent heat transfer is still transfer down a temperature gradient. What you and TTTMan suggest is that if the gradient is decreased because the atmospheric temperature goes up relative to the surface temperature, more energy will be transferred by evaporation. The real world works the opposite way.
“if more energy transfer on average by evaporation (and less by radiation) were possible, it would have already happened.”
OHC doesn’t constantly increase and therefore the combination of variables that determine whether the constant forcing that is increased DLR from CO2 does indeed negate the effect in the real world.
Some questions from an interested amateur.
Back radiation causes more immediate evaporation and quicker reemission of LWR than does a similar amount of solar radiation.
Does that mean that the earth’s temperature should be more sensitive to a given solar forcing than it would be to an equal CO2 forcing?
What percentage CO2 forcing transfers energy to the oceans compared to space and the atmosphere?
How does this compare with solar forcing?
Bob Irvine:
I think you have captured the essence of the question very well.
I will try and answer, at least from a basic point of view, in the next part.
TTTMan,
To quote a stock market adage: nothing goes in a straight line forever.
DeWitt Payne
Perhaps but ten odd years of no net OHC increase as happened from the late 70s to the late 80s is more than just weather.
[…] temperature measurement itself. Here is a temperature profile which was shown in the comments of Does Back Radiation “Heat” the Ocean? – Part Three: Kawai & Wada […]
Evaporation seems to be getting short shrift here with everyone saying the ocean cools by radiation alone. That is absolutely not true. Evaporation occurs constantly at the ocean/atmosphere interface. There is an enormous amount of energy carried away by water vapor in latent heat of vaporization.
Some basics: one BTU heats 1 pound of water by one degree F. It takes over 1000 BTUs to change one pound of water into one pound of water vapor with no rise in temperature.
So the question becomes one of how the evaporation rate changes with and without so-called back-radiation. I have absolutely no attempt made by anyone in these threads to quantify evaporation rate change (if any) due to change in DLR. Until that is done the question of whether DLR helps the ocean stay warm or whether the DLR is removed by a higher evaporation rate and raised by convection to the cloud layer where the latent heat is released by condensation.
Focus on evaporation please.
Dave Springer:
I doubt that anyone is saying this.
Mostly there’s a discussion about how changes in one input of energy will change the temperature (plus a lot of sidetracked discussion).
The original question which inspired Part One was whether energy received at the ocean surface from back radiation was ONLY used in evaporation.
If you take a look in this article, Part Three, under the sub-heading: “How Does Heat Move Through the Ocean?”
– the sun heats the ocean, mostly in the first few meters
– the ocean heats the boundary layer of the atmosphere via convection
– the ocean heats the lower atmosphere via radiation
And under the sub-heading “Wind-Induced Convection and Diurnal Cycle”:
“The other effect is that the surface cools more rapidly than normal due to convective cooling (convective heat transfer to the atmosphere), and therefore is more likely to sink.”
Convection, by the way, includes latent heat removal.
In any case if I asked the question to all the commenters “Do you think that the ocean cools by radiation alone?” I expect that every single one would say “No, of course not”.
[…] Part Three we reviewed various experimental results showing how the temperature profile (vs depth) changes […]
[…] a diagram I posted in the comments of Does Back Radiation “Heat” the Ocean? – Part Three: from Kawai & Wada […]
Less than 20% of ocean heat leaves by radiation. About 10% exits via conduction. A whopping 70% leaves by evaporation. Moreover, much of the summer heating is stored and released in the winter when the air is dryer which handily explains continentality.
Google ocean heat budget.
[…] There’s more on this subject in Does Back-Radiation “Heat” the Ocean? – Part Three. […]