Guest Post by Willis Eschenbach
I was thinking about “dust devils”, the little whirlwinds of dust that you see on a hot day, and they reminded me that we get dulled by familiarity with the wonders of our planet. Suppose, for example, that “back in the olden days” your family lived for generations in a village on a tiny island where there were no clouds. None at all. Ever.
Now, imagine the consternation that would occur if one day, after centuries without a single cloud, a big fluffy white cumulus cloud suddenly popped into existence one afternoon right over the village, hung around for six hours, and then disappeared in the evening. If it happened once, it would pass into legend as the giant white boulder in the sky that threatened to crush the village, and only disappeared after the priests did their most powerful chants …
Next, imagine that over time the appearance of the clouds became more common, but the priests always successfully chased them off … until one day, a plain old white fluffy cloud suddenly started growing straight towards the sky, and it turned black, and miracle of miracles, pure water started pouring out of the cloud! The cloud turned into a fountain! Who knew? If it happened once, it would be spoken of for years.
Next, imagine that over time, the appearance of rain clouds became more common, and the priests tried to make them stick around … until one day the priests were out doing their rain dance in the pouring rain, when without warning, there was a blinding flash of light and a tremendous sound, and all of the priests were knocked dead by some strange, unknown power … imagine the consternation and wonder that would cause, and what kind of legends that would engender …
I bring all this up to highlight the nature of something called an “emergent phenomenon”. The cumulus cloud is an example of an emergent phenomenon. The rainstorms are a second, different emergent phenomenon. Finally, the lightning is a third example of an emergent phenomenon.
So … what are the characteristics of such a creature? How can we tell an emergent phenomenon from all the other inhabitants of the zoo? The following is not an exhaustive list, and some don’t have every characteristic, but here are the things that set an emergent phenomenon apart from its cousins.
• It has a “lifespan”—it is called “emergent” because it emerges from the background conditions at a certain time, lasts for a certain span of time, and then dies out.
• It emerges spontaneously whenever conditions are favorable, and never emerges otherwise. Often this is associated with the passing of some threshold, with emergence not happening at all below the threshold, and increasing quickly once the threshold is passed.
• It has “edges” that make it clearly distiguishable from its surrounding background.
• It must constantly change and adapt to current conditions in order to persist in time.
• It may split into two or more independent copies of itself.
• It can move independently through its surroundings.
• It can do work on its surroundings.
• Once it emerges, it can persist through conditions below the threshold for emergence.
• It is unexpected in the sense that it is not intuitively predictable from the previous conditions. For example, there is nothing about a clear blue sky that says “here come fluffy white clouds”. There is nothing about white fluffy clouds that screams “Close your car windows.” And there is certainly nothing about a warm summer rain that warns “Don’t stand out in a field or a million volts of electricity might pass directly through your corpus delecti …”.
What does this have to do with climate? Well, emergent phenomena are the missing link in the climate models. They are what keep the planet from overheating.
See, the planet is in a funny position. We’re only running at about 70% throttle. About 30% of the sunlight hitting the planet never makes it into the climate system. So never mind CO2, there’s enough energy from the sun to fry us all to a crisp … but that’s never happened.
The reason it hasn’t happened is that there are a host of emergent phenomena that stand in the way of overheating … which brings me back to the dust devils. Here’s a photo I took of some dust devils at night, cooling the surface of the desert from the effects of the huge fire at the left of the picture … dust devils don’t care about the source of the heat.
Now, dust devils have all the characteristics of typical emergent phenomena—they have a lifespan, the do work on their surroundings, they move independently, they change and adapt, they are not intuitively predictable from calm air. In this photo they were emerging next to the fire, then spinning off to the right into conditions where the surface is too cool for them to emerge. So they fulfill all the requirements, they are emergent phenomena … and given that the dust devils do work, then what is the dust devil’s day job? That is to say, what work is a dust devil doing on the surroundings?
The answer is, it is cooling the surface in a several ways. First, it is taking warm surface air and spiraling it up rapidly to altitude, physically removing the heated air from the surface. Next, the increased speed of the wind increases evaporation, further cooling the surface. Next, wind on the earth’s surface increases the “wind chill factor”, which is the increased conduction of heat from surface to atmosphere via surface turbulence.
So a dust devil is a natural cooling machine, a fantastic piece of hardware that is very effective at reducing the surface temperature. And while that is amazing in itself, that’s not the beauty part …
The beauty part is that dust devils only emerge where and when they are needed, at the hot spots. If you’re looking a chunk of real estate, the spot where the dust devil emerges is where the heat is located. This makes it incredibly efficient. Consider how much energy it would take to cool the whole chunk of real estate, and how much less energy it takes to focus the cooling energy exactly where it is needed.
The same is true of the tropical clouds. You don’t want clouds in the tropics all the time, they would reflect all the sunshine, and the planet would cool way down. You only want clouds when it gets hot … which of course is exactly what happens on your average tropical day. In the cool of the tropical morning, it is clear. But when the surface warms, the clouds emerge, and if the warming continues, then the thunderstorms emerge as well.
So to complete the thought, the beauty part of emergent phenomena is that their thresholds are temperature-dependent. As a result, they are independent of both total forcing and total losses. This is a critical point. They are temperature-dependent, not forcing-dependent.
For example, clouds don’t emerge in the tropics when the sun is hot (forcing-dependent). Instead, they only emerge when the surface is hot (temperature-dependent).
And this is why changes in the forcings don’t have much effect on temperatures, particularly on the hot side of the range where the various phenomena emerge in untold numbers. Increases in forcing, whether from CO2, from volcanoes, or from the 5% increase in solar strength over the last half-billion years, don’t affect the temperature much because they don’t affect the emergence thresholds of clouds and dust-devils and thunderstorms. Instead, the emergence of these and other temperature-regulating phenomena is controlled by thresholds related to surface temperature and insensitive to forcing. As a result, the cooling phenomena emerge exactly as, when, and where they are needed, and their emergence is not a function of the forcing in any but the most indirect manner.
Finally, as I mentioned, we’re dulled by exposure to the radical, unusual nature of the emergent phenomena. As a result, for example, the numbers of dust devils could double, and nobody would be the wiser. We hardly notice them, yet they remove huge amounts of energy from the surface in the worlds’ hottest areas. Or, clouds could emerge fifteen minutes earlier in the tropics. Nobody would even remark on it. But either of those shifts would have a profound and lasting effect on the surface temperature …
And that’s why the climate models don’t explain much. They don’t have any of the many emergent mechanisms that preferentially cool the hot spots. No thunderstorms. No dust devils. No waterspouts. No cyclones … and without those temperature-sensitive heat-seeking surface-cooling mechanisms, the models don’t have a chance of reflecting reality.
Regards to all,
w.
NB: Please quote what you disagree with. I can defend my own words, and I am happy to do so. I can’t defend your interpretation of my words. Quote what you disagree with.
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dp says:
February 14, 2014 at 10:58 pm
As you point out, a great number of people are in mystery about the scientific definition of heat. And in the US, one person in four doesn’t believe the Earth circles the sun … so what in either case? Are you seriously proposing that I should base my actions on what the US public doesn’t know?
Again, so what? I use it in a clear and unambiguous manner.
No clue … which is one of the problems with focusing on forcings and ignoring emergent phenomena. We end up without sufficient measurements of things like dust devils …
Well, in first off, it’s energy that is moved to the poles, not heat. Second, in my analysis I’ve used petawatts for the flux of heat to the poles, but you can use other units if you wish …
And your claim that it isn’t possible to know how much energy is moved to the poles? Sorry, it’s been measured, and to good precision, by the CERES satellites.
w.
“Using your dust devils example, how many heat units are needed to create a dust devil of some specific dimension, say dust devil units. ”
—————
I’m sure the NSF would give big Grant monies to someone for figuring out those DD heat units …. but it would be worthless information because no one has a clue as to how many dust devils “emerge” in any given time period or their size, scope and duration.
And ‘fogs’ are in the same “emergent phenomenon” pea-pod …. along with the ‘dust devils’.
What sets the temperature that those emergent phenomena maintain ?
Willis correctly points out that emergent phenomena keep Earth’s temperature remarkably stable despite GHG forcing.
He correctly points out that the vigour and timing of such phenomena can vary as necessary to achieve the thermostatic effect.
In reality all emergent phenomena from dust devils to Hadley cells are mere by products of a single phenomenon – the movement of air. No movement of air, no emergent phenomena.
If emergent phenomena prevent changes in temperature from GHGs then it cannot be GHGs that determine surface temperature so what is it ?
Willis says that emergent phenomena involve work being done and so they do by virtue of the fact that they are simple by products of atmospheric movement.
That work being done is being done against the weight of the atmosphere.
The cause of such work occurring in the first place is uneven surface heating which creates air parcels of different densities next to one another in the horizontal plane so that the lighter parcel is forced to rise above the denser parcel.
Everything follows from that.
The greater the weight of the atmosphere the more work needs to be done for the atmosphere to reach a given height at a given level of insolation and the hotter the surface must become to maintain that atmospheric height.
In practice the external energy source is fixed by the power of the local sun so the height that the atmosphere can attain is then determined by the weight of the atmosphere.
If GHGs seek to disturb that height by slowing energy loss to space then the emergent phenomena become more vigorous or alter their timing just as Willis says and the effect is to accelerate energy through the system faster thereby offsetting the effect of the GHGs.
Embedded Heat Sink Design
http://www.hectronic.se/website1/embedded/forstasidesbilder/bild-6.php
“The temperature can only be kept within the limits by extracting heat through conduction, convection or radiation.
Plate fin sinks extract heat by natural convection.
Heat spreading is essentially area enlarging.
The larger the area the more energy can be removed at the same temperature difference.”
“The Microelectronic Heat Transfer Laboratory of the Department of Mechanical and Mechatronics Engineering at the University of Waterloo has simulations to do various calculations on plate fin heat sinks.”
=======
I built and installed heatsinks on equipment.
Radiation wasn’t then, and is not now taken into consideration when figuring out how to cool an object in atmospheric air.
And the earth itself is nothing more
than the minerals and other composite compounds
that the heat fins are made of –
raw material doesn’t have some special relationship to atmospheric air.
It’s not taken into consideration on black cooling fins, on copper cooling fins, aluminum cooling fins, on grey painted cooling fins, on forest green painted objects in rural areas outdoors.
and it’s not taken into consideration whether the installation is indoor, enclosed, outdoor.
It’s not an included factor in cooling any of those:
to the point where radiation is even included in calculations for it.
They face each other and are aligned to allow cooling from anything but radiation. Radiation emitters don’t face each other in rows of fins.
90% of the energy that leaves something outside, doesn’t leave it, through radiation. Cooling fins are not mounted in shade, with the fins facing the north or south sky, so at night, they can ”radiate 80% of their heat.”
They are mounted, with the fin running vertically, so convection, the by far, most effective method of heat removal – can do it’s work.
When someone designs natural, passive cooling into something they place the fins vertically utilizing convection. Even when they sit big transformers outside, with their painted surfaces being a composite of various substances that resist rust, and water, and abrasion,
surfaces dissipating heat, use convection design built in. Not radiation cooling design.
They are designed completely ignoring radiation
by placing the fins facing.
Not arrayed to emit energy away from each other and the transformer itself. The whole idea is an absurdity that things designed to use primary passive method of cooling use radiation to lose 80%
If the case were that 80% heat lost was due to radiation heat fins wouldn’t be built,
with absolute denial built in, radiation losses hardly even matter.
You have the situation fully reversed.
Heat Sink Convection with Fins Calculator – Engineers Edge
http://www.engineersedge.com/calculators/heat_sink_convection_with_fins_calculator_10048.htm
Again here: radiative losses are so minimal they aren’t even a consideration.
I worked in thermal dissipation and I know what the book says is wrong. The earth itself in raw material in a rock next to a painted transformer don’t have any significant differences in how heat leaves them.
=======
Mr. Eisenbach says:
“Of the half kilowatt per square metre that is lost by the surface,
about 400 W/m2 (80%) is lost as radiation,
about 20 W/m2 (4%) is lost in the form of sensible heat (conduction/convection),
and about 80 W/m2 (16%) is lost as latent heat (evaporation/transpiration)”.
=======
Your information is seen to be very much like this information:
Earth Heat Losses
Long-wave radiation to the atmosphere………..75.5%
Long-wave radiation to space……………….. 4.1%
Evaporation from oceans/lakes/land…………..15.6%
Convection and conduction to atmosphere……… 4.8%
That information comes from a book by a man who writes books about
”Extreme Weather” quoting the IPCC a lot and showing people ”what the models say.”
He works at a place called “Modesto Jr College”
and is anxiously engaged in teaching everyone CAGW is real.
Extreme Weather and Climate – C. Donald Ahrens, Perry Samson – Google Books
http://tinyurl.com/ExtremeWeatherAndClimate
——-
The story of convection/conduction and radiant heat loss being reversed can be found here in his book:
“These values derived from graphs and charts from the textbook “Meterorology Today,” (4th Ed.) by C. Donald Ahrens.”
Earth Heat Gains
short-wave radiation from the sun……………34.7%
long-wave radiation from the atmosphere………65.3%
Earth Heat Losses
Long-wave radiation to the atmosphere………..75.5%
Long-wave radiation to space……………….. 4.1%
Evaporation from oceans/lakes/land…………..15.6%
Convection and conduction to atmosphere……… 4.8%
Atmospheric Heat Gains
Short-wave radiation from the sun……………11.9%
Heat to atmosphere from condensation…………14.4%
Heat to atmosphere from convection/conduction… 4.4%
Long-wave radiation from earth………………69.4%
Atmospheric Heat Losses
Long-wave radiation Radiated to Space………..40.0%
Long-wave radiation radiated to earth………..60.0%
——-
“Of the half kilowatt per square metre that is lost by the surface,
about 400 W/m2 (80%) is lost as radiation,
about 20 W/m2 (4%) is lost in the form of sensible heat (conduction/convection),
and about 80 W/m2 (16%) is lost as latent heat (evaporation/transpiration)”.
=======
This makes it hard for anyone to understand even approximately how much energy there is to make a dust devil
if the handling of energy between radiant and conductive/convective loss
are exactly reversed
and the convective handling causing the “Emergent Phenomena” like Dust Devils
is entered as insignificant,
simultaneously calculating and theorizing
the radiant loss
which is so small it is not calculated into, heat loss design
is believed and thought of as doing 80% of the work.
Peter LeBorde says:
February 15, 2014 at 2:32 pm
“….. surfaces dissipating heat, use convection design built in. Not radiation cooling design.
They are designed completely ignoring radiation by placing the fins facing.”
————————-
Actually, it is “conduction design built in”, ….. is it not?
And convection is relied upon to transport the heat away. And “forced” convection is the most efficient method, ……. right?.
Willis, as usual you’ve ignited quite as conversation here with many cogent points made by both yourself and by many other commenters – won’t try to single them out. But unless I’m wrong, I perceive a huge stake being driven into the heart of AGW, by the enormous number and magnitude of phenomena the AGW theory doesn’t account for, the computational problems, the simplistic, even teleological assumptions AGW makes, and all the related issues you and the other folks here have raised. Good show, people, a great read.
The concept emergent phenomena tells that the behavior of the phenomena is complex. Simple course and effect relationships cannot explain it. Statistical analysis does not give meaningful results.
Typical rules governing an emergent phenomena contain non-linear relationships, feedbacks and time lags. Simple linear extrapolation does not work.
Think, for example, a kettle of water on a stove and the relationship of the input power and the temperature of the air just above the water level. Nothing happens, when you put the power on. After a while the temperature starts to rise but this rise ends though the power is still on.
If you put a cover on the kettle, the rise ends earlier but the final temperature remains the same.
Models are the way to understand the behaviour of emergent phenomenon. To create and validate a model you need to have accurate and relevant data. When you run the model all of the variables of the model must match the observations all the time. If not, you need to correct the model.
Peter LeBorde says:
February 15, 2014 at 2:32 pm
Peter, it seems that your claim here is that for the earth, there is little or no heat loss through radiation.
Bad news. There are lots and lots and lots of observations and measurements that disagree with you … among them are a host of records, made in many places, from land, from satellites, from ocean buoys, from airplanes, of direct measurements of the upwelling radiation that is given off by the surface.
The measurements all agree that contrary to your claim that radiation is immaterial, the opposite is true— radiation is the single largest means of heat transfer from the surface to the atmosphere… sorry, but that’s what the observations say. It’s been measured.
Certainly, you are correct that if you have thin vertical fins of some highly conductive metal with appropriate spacing between them, your major heat loss will be through conduction/convection … but the ocean has no such fins. Nor does the land, nor the ice, or does any part of the natural landscape have thin fins of highly thermally conductive metal. So no, the earth is not the same as a finned heat sink.
Finally, you claim that radiation is not taken into consideration with heat sink design. However, a quick google of [ “heat sink” radiation ]finds literally hundreds of papers dealing with the analysis of the effects of radiation in heat sink design … so while I’m sure that you are correct that in your particular corner of heat sink design radiation was not an issue, google shows that there are many heat sink designers out there for whom it absolutely is an issue …
w.
An almost perfect example of a well designed “heat sink” that emits copious amounts of thermal (heat) radiation is the “ole timey” cast iron wood/coal burning heating and cooking stoves.
Especially the oven compartment of the cooking stoves.
And many of said stoves were intentionally designed with “raised” lettering, filigree, etc., on the outside surface of the cast iron because said thermal (heat) radiation will occur more readily off of said “extrusions” than it will off of a smooth surface.
And that thermal radiation is powerful enough to “burn your butt” iffen you stand too close, …. too long, …. next to a “hot” cast iron wood/coal burning heating or cooking stove.
All atmospheres are laded with particulates of solids which are far better absorbers and emitters than any GHGs.
So, even if one has a radiatively inert atmosphere there will be plenty of particulates absorbing energy and passing it between themselves so that the non radiative gases can warm up or cool down by conduction from or to the particulates.
It isn’t just a matter of conduction to and from the surface.
Mr. Eisenbach the heat sink field I was in isn’t a corner.
I was recruited by my friend who worked in it
into regional, electrical power grid installation updating equipment.
All around were people who have the job of managing thermal emissions outside to the atmosphere.
The electrical field is very much about handling thermal emissions: because in matter it generates heat;
the people responsible for the electrical field measure electricity itself in an expression of power, as heat.
What you tell people is the men who set the giant transformers into the ground
were and remain completely oblivious every single thing they have designed
for convective heat removal is designed, in reverse.
They don’t know what they are designing to have heat removed through convection
are actually emitting 80% of their energy through radiation.
Every heat sink mounted so the fins face each other depending on air getting properly between them
to make them cool through convection ignores the greater energy loss path.
Convection actually is negligible. The entire earth and everything in it,
including every single power transformer ever set outside with fins facing
since invention of electrical power, is designed not just wrong but reverse.
No they are not. Every outdoor transformer you walk by and drive by
with giant, vertical fins, facing each other in long rows,
so they can use the predominating power of conductive convection,
is not reverse.
The man who told you what is in that book is reverse.
The men who taught me did not tell me reverse.
We talked about how the equipment we worked on was convectively cooled.
We didn’t say, ”remember, you’ve got to remember your radiant cooling.”
Different things I heard working in the power grid were
”Well, remember your radiant losses are negligible; that’s why we can put this case around it;
as long as air comes in the bottom and goes out the top – particularly if the heatsinks are aligned with the holes –
– the cabinet will hardly heat up at all.”
When someone said
”I thought the losses were basically radiant.”
We would say ”They are until the air moves, but as soon as the air moves,
it pulls in another molecule and another and it immediately cools everything down.
It immediately swamps radiative losses, to the point where if you can keep the air moving,
you can get the thing down to almost, room temperature. Radiation matters very little.
That’s why we can sit it so close to other things.”
I heard things like,
“Conductive power to move heat through the metal body to the colder fins is very powerful;
Because it’s all mounted metal to metal, essentially, except where the insulators keep things from touching, the heat will travel to the coolest points on the thing
and if you set it up right and let it flow over, and expose the fins to a steady stream of moving air, you’ll be surprised how cool it can keep it.
You can feel some radiation but not much,” he would say touching something very nearby,
“but convection is pulling that away too, here on the wall; and the wall’s flat.”
Things like that.
Not
”You’ve got to remember that 80% of the heat lost from that tranformer is through radiation alone
but the convection is very minimal, that’s why we built every transformer we ever sat outside, with vertical fins on the hotter areas,
so the almost non existent convection
would take some heat away.”
You and the man from Modesto Jr College a man associated with a long line of obviously rigged ‘research’
specifically, in math fraud,
say there are ”many many measurements” of “the earth losing ‘80% of it’s energy to the environment through radiation.”
Structures don’t have
“the most modern energy efficient radiation damping and enhancement” built into their architecture Mr. Eisenbach
to ”take maximum advantage of the 80% losses through radiation, going on around us in structures every day.”
Energy advisors don’t tell us all ”Obviously, we need to have radiant energy loss foil
put properly around every thing we have, so we can heighten energy efficiency
by stopping the tremendous losses in 80% radiant energy we all waste oil on.
We don’t all talk about how
”We need to start making our architectural standards address the immense 80% energy losses
that actually come from radiation. Convection and conduction are actually almost nothing, why do we
even talk about those? We need to approve buildings for energy efficiency according to their radiative energy profile.
Not the barely even signficant convective/conductive energy profile!”
What you are saying is reversal of the way the situation is Mr. Eisenbach.
Realize what it has been meaning,
all these years
as you were opening equipment
to find the fins mounted vertically
in line with air flow,
driving by giant transformers with their facing, vertical fins,
driving by and walking by electrical cabinets
with equipment inside that is cooled
by a row of holes at the bottom,
a row of holes at the top,
driving the convective cooling
that predominates wherever air flow is free
Incidentally the fins are spaced apart because the earth doesn’t have fins Mr. Eisenbach.
It is a convex shape which feeds convection very well.
It is what makes those Dust Devils.
The fins are a compromise for space saving considerations.
Willis Eschenbach says:
February 15, 2014 at 10:54 pm
Peter, it seems that your claim here is that for the earth, there is little or no heat loss through radiation.
Bad news. There are lots and lots and lots of observations and measurements that disagree with you.”
Peter LeBorde says:
“Mr. Eisenbach…”
Mr LeBorde, you repeatedly refer to Willis as “Mr. Eisenbach”. To be correct, it is: Willis Eschenbach.
I only point this out because you seem to be arguing with Willis. But if your reading comprehension is such that you can’t get his name right…
…see where I’m going with this?
++++++++++++++++++++++++
Willis, kudos for another fascinating and interesting article. Too many folks rely on computer models to support their belief. No wonder they are so wrong about man made global warming.
But since they don’t want to accept the planet’s authority [temperatures are not rising as predicted], then I doubt they will pay attention to your lucid explanation.
Most of us here do, though, and as always, it’s a pleasure to read.
Peter LeBorde says:
February 16, 2014 at 12:38 pm
Hogwash, I said no such thing. This is a perfect example of why I ask people to QUOTE MY WORDS, as I said in the head post:
Did you read where I said that in the head post and decide to ignore it, or did you just skip it, or is your reading ability that bad, or what??
In fact, I said:
Can you read that, Peter?
If so, QUOTE where I said anything about heat sink designers not knowing their business. That’s nothing but your fantasy … and since that’s the shabby, ugly quality of your fantasy, why should anyone pay the slightest attention to your fantasies?
w.
Stephen Wilde says:
February 16, 2014 at 12:33 pm
Thanks, Stephen. While I agree with you in principle, numbers are your friends here. How much particulates are there, and how much effect do they have?
I never said it was “just a matter of conduction”, so I’m not clear what your point is here.
w.
Peter LeBorde says:
February 16, 2014 at 12:38 pm
“Every outdoor transformer you walk by and drive by with giant, vertical fins, facing each other in long rows, so they can use the predominating power of conductive convection”
—————-
Peter, happy to see you are now referring to that transformer thingy as “conductive convection”.
But anyway, Peter, … the posters on this forum that are knowledgeable in/of the Physical Sciences and especially the transfer of thermal (heat) energy via radiation, conduction and convection …… pretty much know exactly why the designers of heat sinks, electrical transformers, etc., ……. design the physical features of said “items” in the configurations that they design them. And Peter, the environment in which said “items” are to be used is also a critical factor in determining their design.
And Peter, the “convection” part of “conductive convection” is actually referring to the “transporting” of the energy from one place to another …. and not the “transferring” of it from one (1) entity to another “entity” (not transferring it from one [1] molecule of atmospheric gas to another molecule of atmospheric gas).
Samuel the act of transfer like you say of course , is conduction and the movement is advection hence the word ”convection” bud
I’m sorry that I ignored you speaking before I have to look at this blog and others only a few minutes at a time.
Have a good morning.
Convective heat transfer
From Wikipedia, the free encyclopedia
See also:
Heat transfer and convection
Convective heat transfer, often referred to simply as convection, is the transfer of heat from one place to another by the movement of fluids.
Convection is usually the dominant form of heat transfer in liquids and gases.
Although often discussed as a distinct method of heat transfer,
convective heat transfer involves the combined processes of conduction (heat diffusion) and
advection (heat transfer by bulk fluid flow).
——-
Advection
——-
Etymology Latin advectio (“act of bringing”), from advectus (past participle of advehere
(“to carry to”), from ad- + vehere (“to convey”))
Noun
advection
(earth science, chemistry) The horizontal movement of a body of atmosphere (or other fluid) along with a concurrent transport of its temperature, humidity etc.
Peter LeBorde says:
February 17, 2014 at 3:14 pm
“Noun – advection —-(earth science, chemistry) The horizontal movement of a body of atmosphere (or other fluid) along with a concurrent transport of its temperature, humidity etc.”
———————-
Specifically stating the plane of movement as being “horizontal” makes the statement in error or wrong. The movement can be vertically up or down, sideways, lateral, horizontal and/or every which way.
Uh, .. uh, ….. you can not transport temperature, it is not a physical entity.
——————
The atmosphere is not a fluid, it is not a physical thingy.
An atmosphere is only an atmosphere if it contains gas(es), the same as a community is only a community if it contains people, pllnts, animals etc.
And I don’t care what your earth science book says.
To wit:
Convection is the movement of a fluid, typically in response to heat.
Advection is the movement of some material dissolved or suspended in the fluid.
http://physics.stackexchange.com/questions/24489/what-exactly-is-the-difference-between-advection-and-convection
End of discussion.
“only half of the radiation goes to space. The other half goes back downwards, making the surface warmer than it would be in the absence of the GHGs.”? But where did this heat come from that the atmosphere is so equitably distributing? It wasn’t intercepted on its way down (DSW or DLR). It was “collected” from the surface by conduction and evaporation in the first place. That the “collection” is only net ~50% effective in transferring heat to space is not thereby make it a net warming. As long as the OLR is sufficient to balance the DLR and DSW, it is a cooling factor. Some of the OLR is ‘windowed’ directly from the surface, some comes from (let us say for convenience) the TOA. If we magically removed the GHGs establishing the TOA average radiation level, only the surface-shine-through-the-IR-window and mass loss/sputtering from the thermosphere would still be available, and they would have to crank up considerably (heat up) to do the job.
typo: does
isnot thereby …