An appeal to the climate science blogosphere

Now this is how I have always believed “scientific inquiry” was supposed to be … form a theory, test it and if it seems to hold up, ask others to try and poke holes in it.
How refreshing!

I am becoming more and more impressed by Judith Curry. She is becoming a fine, courageous scientist. If only others would adopt her principled moxie, we might actually progress climate science. Kudos. GK

“a main weakness of the[ir] models is their limited ability to simulate vertical air movement, such as convection in the tropics that lifts humid air into the atmosphere.”
What, fossil fuel CO2 is going to cause the “destruction of creation” but it can’t even do that?

Oops … That should read “dipolar” … Not “bipolar” …

Any meteorological textbook will provide a discussion of buoyancy-based convection: how a warm air parcel ascends being lighter than the surrounding air. The convective instability of moist saturated air, so far neglected by the meteorological theory, is different. Any upward displacement of a saturated air volume, even a random fluctuation, leads to cooling. This causes the water vapour to condense.

I don’t think it is true at all that this is ignored in meteorology. Here in Rochester, we get lots of lake effect snow and they are constantly talking about the instability produced by the cold air blowing over the warm lake waters. I used to think the role of the lake was just to make the air more unstable because it heated it and that another independent role of the lake was to provide the moisture that leads to the precipitation. However, I recently went through the module on lake effect snow available here http://www.meted.ucar.edu/ and understood for the first time that the addition of moisture to the air itself also increases instability because of the fact that a saturated air parcel cools less as it ascends (because the condensation of the vapor vapor releases latent heat). While this was a new understanding to me, I found no evidence that it is new to those who are actually formally trained in meteorology, atmospheric, or climate science (which I am not)…In fact, it seemed to be such old-hat to them that they basically took it as a given.

Well, golly gee, that leaves me out . . .

Good to see Dr. Judith Curry willing to weigh in. But not surprising – she’s still a scientist.

I actually know someone who can possibly help. Anastasia, drop me a line. The person I know did atmospheric chemistry with NASA for several years.

Well I haven’t read the paper yet (I will); but some immediate trivial questions come to mind.
#1 Some of the strongest winds on earth occur over the Antarctic plateau; which also is among the driest places on earth; so I don’t imagine a lot of water condensation going on there to start up winds ?
#2 How does the pressure created by molecular collisions required to keep water droplets buoyant, compare with the actual vapor pressure of the same amount of water before it condensed ?
Does this paper explain those things ?
But as to the approach (to review), seems like an interesting way to consider things.

Martian wind speeds may average around 20-30 mph while bursting much higher during storms. Mars’ atmosphere is 0.03 % water vapor.
I’d say the phase change of water plays little role, if any, in the Martian winds, why should it play a significant role here on Earth?
I don’t believe temperature gradients explain winds on Earth either. I expect if the planet didn’t rotate, then there would be no wind, and only small mixing of atmospheric gases at the tropics.
My belief is that the mountain ranges and canyons stir up the atmosphere as the planet spins.
The average wind speed on Earth is about half of that on Mars (quick Internet search, not definitive). Mars has the largest mountains and canyons in the solar system, and a higher wind speed than Earth.
To me, this lends credence to the physical movement of air creating winds, not a temperature difference or water phase changing.
I would expect an easy experiment would be to spin a perfect sphere in a test chamber with several colored gases injected at different temperatures. I don’t think the gases would mix that fast. And once mixed, I don’t expect much wind would be observed.
Compare that to a spinning sphere with ridges and indentations to simulate mountains and canyons. I expect the gases would mix much faster and there would be a sustained wind observed.

“How does the pressure created by molecular collisions required to keep water droplets buoyant, compare with the actual vapor pressure of the same amount of water before it condensed ?”
Strange, I would have thought that water droplets migrate downwards,(as allowed to by air friction moving up) until they reach less than saturated air, then volatize, thus creating an illusion of staying buoyant.

As I understand the paper (read not too carefully) and most comments, the main question is the relative importance of latent heat contributions as compared to a mass defect contribution. The latter is basis for the claim of something like a “new theory of wind”, while the mass defect in the view of most commentators is a relatively small correction to latent heat produced buoyancy (in my opinion, too). The latent heat is very large (of order 0.4 eV per H2O molecule) and unique among gases, as it is produced mainly by the hydrogen bond and not by, e.g.; van der Waals forces, as Chris Reeves claims.
If the paper is revised along the line “first time analytical treatment (if true) of the mass defect correction to latent heat buoyancy” I would see a chance for acceptance. I guess that is about the line which Judy Curry advocates.

I will join with others in wishing Jeff a pleasant well deserved break! I would leave him with this quote; “Any activity becomes creative when the doer cares about doing it right, or better.”
Rest well.

We are very grateful to Mr. Anthony Watts for carrying our appeal at WUWT. We hope very much it will evoke a constructive reaction.
George E. Smith
January 21, 2011 at 9:47 am

#1 Some of the strongest winds on earth occur over the Antarctic plateau; which also is among the driest places on earth; so I don’t imagine a lot of water condensation going on there to start up winds ?

The strong winds over the Antarctica are due to the peculiar relief of the continent, rapid radiational cooling of air due to a very low vapor and clouds (greenhouse substances) amounts and concentration of mechanical energy in a narrow area. The continent occupies less than 3% of total Earth’s area. Atmospheric dynamics in the Antarctic versus atmospheric dynamics in the tropics, where most kinetic energy is generated, have different mechanisms.

#2 How does the pressure created by molecular collisions required to keep water droplets buoyant, compare with the actual vapor pressure of the same amount of water before it condensed ?

Water droplets are not maintained in the atmosphere by pressure exerted by molecular collisions (see here, Sections 2 and 3, p. C12009, for a more detailed discussion of this inconsistency as implemented in numerical models). Water droplets can only be maintained if there is an ascending air flow (i.e., a macroscopic air movement).

Ryan N. Maue
January 21, 2011 at 10:39 am

Why isn’t this paper submitted to the Journal of Atmospheric Science or another journal with a long-established legacy of editors and reviewers that have sufficient experience and skill to understand the arguments?

This is an interesting point. It is presumed that the Editors and Reviewers of ACP (a peer-reviewed journal with impact factor of4.88) , with the Advisory Board chaired by Noble Prize winner Dr. Paul J. Crutzen, do not have sufficient experience and skills to understand the arguments. Personally, I do not think so.
Another logical possibility is that the climate community is — on average — unprepared to an open debate of science. In this case, the extraordinary low proportion, <1/10, of which the referee table testifies, would mean that people are scary of publicly expressing their views, even anonymously. In the ACPD the authors are entitled to reply to any review and may expose errors, if any, in a referee's assessment of their work. In contrast, in the dominating closed peer-review system the exchange between authors and negative referees is not encouraged.
I find strange the idea that somewhere there is a secret and localized group of climate scientists who "understand the arguments". Nobody knows them, and even if somebody gets to know and approach them with a review request, they decline the invitation. Only the right Editors "with skills" may approach them and hope for a favorable outcome of their invitation.
Really, shouldn't an average community member be competent and responsible?

Just let me get this one thing straight . . . Scientist do say that part of the cause of wind “is caused by the fact that Earth hurls around the sun as a part of our solar system.” . . . . plus the fact that it spins once around on it’s axis in a 24 hour period of time . . . RIGHT????? I mean to ask . . . this is assumed and acounted for right?
I mean Bill Nye the Science Guy can speak in plain english . . .

At last a true crusader in the cause of blog science. Denial Depot has been fighting for just this much maligned cause for…well…some time:
“We are not afraid to be called climate “deniers”. In fact we embrace it as medal of honor bestowed on us by our alarmist foes. Galileo was a Denier. It is not an insult. I call this blog “Denier Depot” for that reason.
Welcome to my climate science blog.
I believe that one day all science will be done on blogs because we bloggers are natural skeptics, disbelieving the mainstream and accepting the possibility of any alternative idea.
We stand unimpressed by “textbooks”, “peer review journals” and so-called “facts”. There are no facts, just dissenting opinion. We are infinitely small compared to nature and can’t grasp anything as certain as a fact.
Nothing is settled and we should question everything. The debate is NOT over Gore! When so-called “experts” in their “peer reviewed journals” say one thing, we dare the impossible and find imaginative ways to believe something else entirely.”
http://denialdepot.blogspot.com/
Here, fellow deniers, you can read ground breaking stories every bit as imaginative as the “Where do winds come from?” yarn!! Such as this online comments reviewed piece proving that Arctic ice cover is, as us hard core deniers have known all along, actually INCREASING!!
http://denialdepot.blogspot.com/2010/09/arctic-news-and-global-cooling-update.html
Yes, blogosphere scientists “we have faith in you”

I apologize profusely for not yet being in a position to provide assistance.
Alas, my conflict of interest is not yet resolved.

They’re getting rather confrontational over at the Nation (having lost the science debate, basically):
http://www.thenation.com/article/157903/confronting-climate-cranks

Wow Richard Holle, that was some poetry.
I’ve recently found out about winds on Venus: near the surface they are apparently reasonably quiet, but higher up they are hyperventilating: blowing faster than the planetary rotation. Some 200 kph – with the net effect that high up Venus’ temperatures are pretty well mixed despite its extraordinarily long night. But hey, how come winds can blow that fast?
Right now I’m soaking up clues regarding electrical and magnetic influences which I think scientists have barely started to work on properly. It seems to me that the higher up one goes in the atmosphere, the more we see effects dominated by the plasma state of matter, rather than the gas state of matter. And it seems to me that electrical charges can sure have huge influences, far more than are generally realized.
Richard Holle reminds us about electrostatic forces in effect enabling clouds to exist at all, if I’ve understood correct. That sets off a huge flash of light for me. The hypothesis here is, with the formation of clouds, do we essentially have a plasma formation really low down in the atmosphere? and are we looking to ionized plasma laws for some (not all) of the clues as to behaviour?

Anna, have you looked at Erl Happ’s work that looks at winds relating to sea level pressure differentials? I found it very thought-provoking, in particular I’d like to know why there is an extraordinary permanent latitudinal dip in pressure at 60 degrees South. Now is this evidence for your hypothesis? At the physical level, 60 degrees S +- 5 degrees is the ONLY place on the globe where winds can blow East-West continually over the oceans without interruption from land.

peter_ga says:
January 21, 2011 at 3:08 pm
This theory may be indirectly attacking one of the planks of global warming.
——-
You hit it on the nose there!

Here’s our lovely author…
http://thd.pnpi.spb.ru/~makariev/

@sky says:
January 21, 2011 at 12:22 pm
“…Publication of Makarieva et al would make a vital addition to meteorological understanding. In factors that affect climate, however, the thesis is more a scientific footnote than a chronicle of a revolution, because the winds and currents that circulate heat poleward from the tropics are the product of macro-scale horizontal pressure gradients and planetary rotation, rather than the intricacies of meso-scale moist convection and condensation….”
I think you should go read the paper. Their thesis is that moist convection systems in fact produce a global horizontal pressure differential, sort of, you know, like that observed in nature.
Actually, each thunderstorm is a micro or meso (I don’t know your scale) affair. But the ITCZ is a global/macro thing operating 24/7. In the same vein, volcanoes are micro affairs, forming here and there above a subducting plate that stretches in some cases for thousands of miles. But they mean a heck of a lot to us people.

“”””” stephen richards says:
January 21, 2011 at 11:40 am
Remember the JJ Thompson oil drop experiment
We talk about Millikan’s oil drop experiment in the UK. “””””
Well I’ve never heard of JJ Thompson’s OD experiment; which doesn’t mean he never did one; just that nobody told me or asked me to come and watch. Adn Milliken used an oil droplet, because earlier attempts with water, failed, becasue the droplet evaporated too rapidly, so he changed to a low vapor pressure oil instead. Of course that experiment was to measure the electron charge; and that is why in my question to Dr Makariev specifically called for zero charge conditions so my water droplet, would be influenced only by gravitation, kinetic collisions with anything else in the enighborhood.
Even a single neutral atom can fall freely under gravity, in a good enough vaccuum; and of course can be caught in an “Optical Trap” and suspended, as was done by Steven Chu to win his Nobel Physics Prize. Those who made optical traps years before him, and taught him how to make them, did not receive any Nobel Prize; nor did any of Chu’s co-workers. But of course the Nobel Prizes are NOT Political; unlike the Peace Prize; which IS totally political.

“”””” Ed_B says:
January 21, 2011 at 10:00 am
“How does the pressure created by molecular collisions required to keep water droplets buoyant, compare with the actual vapor pressure of the same amount of water before it condensed ?”
Strange, I would have thought that water droplets migrate downwards,(as allowed to by air friction moving up) until they reach less than saturated air, then volatize, thus creating an illusion of staying buoyant. “””””
Well Ed; well if you read my response to our lead author, you should come to look at thw water droplet from the point of view od some kind of Maxwell’s demon riding along on our droplet. I specifically excluded a charged droplet, so w could consider the droplet to be under the influence only of gravity, and whatever influence it’s environment has. Gravity and the EM force both have infinite range; and the strong and weak forces are both too short range to affect our droplet.
So you talk about “air friction moving up”; Dr Makarieva talked about an air mass flow upwards. But HOW do those manifest themselves to our Maxwellian pilot and his chariot ? Well I’ve excluded all the “action at a distance” forces other than gravity, which will cause the droplet to fall to earth; so that leaves actual mechanical contact with other material objects, as the only means of counterracting gravity. And assuming clean air, that can only be collisions with air moelcules; well we’ll excuse the occasional Cosmic ray coillision shall we.
Both you and the good Dr. are correct, that the neighboring air mass, must have a net upward flow (z-axis), because the net result of all the collisions is to not move the droplet, relative to the centre of mass of the local air; except as dictated by gravity.
I’m simply saying that in the centre-of-mass space of the local environment (which is also subject to gravity) the average effect of all the molecular collisions must be zero, but they must impart a net upward rate of change of momentum in Laboratory space to keep the droplet moving upward with them, and that means the weight of the droplet results in a reaction on those neighboring molecules which is equivalent to a net downward pressure on those local air molecules, so the droplet’s weight does result in an increase in the local pressure as seen by the molecules; the same thing would happen if they were colliding in their upward journey; with an immovable object.
So I’m arguing that the weight of the liquid droplet(s) DOES contribute a non-zero increase in the local air pressure; and I’m simply curious as to whether Anastassia, and her colleagues has compared that pressure to the corresponding vapor pressure (as a partial pressure constituent) in the case, where that same mass of water is actually in the vapor phase.
We all understand the concept that if a mass of water vapor condenses to droplets, that the occupied voume (by those H2O molecules) drops precipitously, and given that that previously occupied space is now available for the non-condensing species; the gas law equation of State pressure should drop; but even here you have to be careful, because those equations of state also contain the number of gas molecules; which will also change with the condensation of the water.
Without actually reading the complete paper thoroughly, I am not going to speculate further; I just wanted to raise that little idea of who’s supporting the water droplets.
I don’t know why Dr Curry chose to put out an open public review; frankly I don’t care much either; I’ll assume she had her reasons, and it is bettwer to start with at least one review whether confidential or open, and frankly I don’t know whay referees would be so hesitant to give these authors a fair reading. If you are that shaky about your ability to read this paper and give it a proper critique; lest you be found to be approving another cold fusion paper; then maybe your knowledge is not sufficient that you should be reviewing any papers on this subject.
If the paper was total BS, or a cold fusion look-alike; well surely a competent reviewer would be able to declare it so, without fear.
Folks who like to hide behind pseudo-nyms (as distinct from “handles) know what their stuff is really worth; or they would be proud to put their own name to it.
Dr Makarieva is apaprently not shy to put her own name on her paper; too bad that “the experts” are too chicken to even have their name near it even in a confidential review.
So we amateurs should fill in while the experts circle their wagons; or gather some cajones. I’m certainly a neophyte when it comes to cloud chemistry; well any kind of chemistry; but I’m not too shabby when it comes to Physics, and Mathematics; which I see is Dr Makarieva’s forte; but I’m well short of her level.
An interestingg day Anthony; you too Chasmod.

@Mike Mangan says:
January 21, 2011 at 4:23 pm
Thanks for that. She is pretty (and scary smart)!

Mike Mangan, WOW! 16 years old when she went to the Polytechnical, and just 26 when she recieved her PhD. No wonder there are few takers to referee her groups’ paper, they are probably afraid that they won’t understand half of it!

Chris Reeve says
——–
In other words, the liquid state of matter is an electromagnetic resonance of molecules.
——–
No it’s not.

A couple of suggestions for reviewers: Lubos Motl of motls.blogspot.com and Nir Shaviv of Hebrew University.

I would like to nominate two possible reviewers. How about G. G. Anagnostopoulosa or D. Koutsoyiannisa? They are hydrologists with an interest in climate and might have an interest in this new theory.

sky
January 21, 2011 at 5:23 pm

I read the paper some time ago and am repeating here my comments (on tAV) on the “danger of over-reaching” on the spatial scale of the applicability of their thesis. Condensation, after all, is nowhere near as ubiqutous as the winds are.

Thank you for your continued interest. In a nutshell, the physical mechanism that is proposed: the area where condensation occurs becomes a low pressure area due to continuous removal of gas from the gas phase. The air from the neighborhood streams to that area and ascends there sustaining condensation. Deprived of moisture, it returns to ‘the neighborhood’ in the upper atmosphere and, as matter conservation prescribes, descends there. There is no condensation in the descending air. So, every circulation pattern driven by condensation will necessarily have a ‘descending’ part with no condensation.
What are the grounds for a statement that condensation is a micro- or mesoscale process? What does such a statement mean at all? Molecular collisions are ‘microscale’ as well, but this does not prevent the ideal gas law from being globally applicable to the atmosphere.
If we look globally, clouds cover over 50% of the planetary surface. This means that the area that are permanently affected by condensation IS globally significant. Such a pattern also indicates that the ascending and descending regions of condensation-induced circulation patterns are, on average, of approximately the same size.

My suggestion would have been to submit a theoretical paper first to a pure physics journal, and only then–armed with conclusive experimental data from field measurements–undertake the daunting task of revealing the implications to climate scientists.

In the post we provided a link for those interested in what and where has been recently published on this topic. We are not aiming to get a particular paper published. Our goal is to generate interest and provoke a discussion in the climate community.

Mike Mangan says:
January 21, 2011 at 4:23 pm
Here’s our lovely author…
http://thd.pnpi.spb.ru/~makariev/
Thanks Mike, never argue with beauty.

So meteorologists don’t comprehend thermodynamics AND fundamentals of chemistry. What else is new?
For separation of tiny droplets of liquid H2O, preventing raindrops coalescing into large enough drops to fall, try static electricity. Pith balls in a Leyden jar. Clouds have extremely large negative electrical charges, doth causes the lightning to discharge huge numbers of electrons from clouds to ground (earth) in lightning strokes, allowing the finely divided H2O particles to come together, and fall as raindrops to the ground.
In case no one noticed, the larger and faster the number of lightning strokes, the faster and larger the raindrops fall and become. Simple observation.

Bernd Felsche
January 21, 2011 at 10:46 pm

The total energy of a given parcel (mass) of moist air is the sum of heat “stored” in the molecules, kinetic energy due to the velocity and the potential energy due to the mass under gravity at altitude.

Thank you forthis comment. This is how things are conventionally represented in models. In reality, in the presence of condensation, partial pressure pv of the condensable gas — water vapor — represents another store of potential energy. Namely this energy (not latent heat) has been so far neglected. When an air volume containing saturated water vapor is adiabatically displaced upwards and some vapor condenses, there appears an upward-directed pressure gradient force that is available to accelerate air.
This force is related to the decrease in the amount of gas, not to the amount of heat released. Just appreciate that these two processes are physically different and governed by different physical constants: theoretically, we can have a chemical reaction in the atmosphere that would not change the amount of gas molecules but lead to either release or uptake of heat. On the other hand, we could have a reaction that changes the amount of gas molecules but does not lead to any appreciable heat release or uptake. All emphasis in meteorological theory has been the effects of latent heat release. The formation of pressure gradient force (the dynamic aspect of condensation) due to the change of the amount of gas has not received the needed consideration.
Readers interested in specific details on how the potential energy from condensation was neglected in a numerical model designed to described a moist atmosphere (while latent heat release taken into account), please, read here starting from Section 2 on the bottom of p. C12009. Warning: this may demand the acquaintance with the other materials in the discussion.

I will nominate three other possible reviewers. Hopefully they have not already been asked. Richard Lindzen of MIT, Petr Chylek of Los Alamos National Laboratory or Stephen Schwartz of Brookhaven National Laboratory. Surely one of those guys would be interested, although they might not have the time.

Anastassia,

When an air volume containing saturated water vapor is adiabatically displaced upwards and some vapor condenses, there appears an upward-directed pressure gradient force that is available to accelerate air.

Perhaps you can justify the assumption of an adiabatic process. It’s probably close to valid for gases which don’t radiate well, but significant water vapour and the formation of liquid condensate facilitates radiative heat losses. i.e. they can cool without necessarily experiencing an expansion or collision with cooler molecules.
I admit that I’ve only briefly scanned your papers and not worked through them to gain a full appreciation of how you think.

Anastassia Makarieva:
How about one of these fellows:
Ralf D. Tscheuschner
Gerhard Gerlich
Their paper: Falsification Of The Atmospheric CO2 Greenhouse Effects Within The Frame Of Physics is a heavy-duty treatise in thermodynamics.

Bernd
Consider the simplest case: a pure vapor atmosphere over a flat isothermal Earth. Let us introduce a sufficiently large vertical temperature gradient. In this case there is much saturated vapor above the warm oceanic surface and very little in the upper cold atmosphere. The vertical pressure gradient of saturated vapor is highly non-equilibrium (i.e., hv is much smaller than h) due to large temperature gradient.
Governed by this upward pressure gradient force, there will appear a unidirectional upward motion of vapor that will condense in the upper atmosphere and return to the surface as liquid drops. (Note that in order this to be possible, all latent heat that is released in the upper atmosphere should be disposed to space via radiation. But this condition is implicitly accounted for after we have specified the temperature lapse rate.)
If we now add non-condensable gases the ‘circulation’ can no longer be 1-D imensional, because, unlike vapor which turns to liquid, dry air has nowhere to go as it ascends but to go downward somewhere else. We will witness an appearance of circulation cells that include both horizontal and vertical parts. This is what the condensation-induced dynamics is about.

Without getting into the deep scientific arguments, lets just look at what happens in the real world from a glider piot’s point of view. (Guess what my online name means).
A glider pilot is losing altitude at his minimum sink rate of 150 feet per minute (fpm). As he approaches a developing thermal, that sink rate may increase to 300 fpm or more down, and as his altitude drops the poilot may even start to look for somewhere to land. Then Eureka, at 1000′ above ground he hits a weak thermal and starts to climb. His climb may initialy be 200 fpm which means the air around him is actually climbing at 350 fpm. For that air mass to be rising, there must be wind on the ground driving in to replace that rising air.
The glider pilot looks up, and somewhere above him he sees a cumulus cloud with a nice dark base. Now as he climbs slowly up towards that cloud, his rate of climb increases; maybe to 500 fpm. So where is the energy coming from to cause that air mass to be moving faster. Obviously there is a pressure difference as he approaches the cloud and air is being drawn in the side of the thermal. The hot ground may have been the kicker, but it is what is happening inside the cloud that is now providing the lift. At cloud base it is common for glider pilots to have to open their air brakes to prevent being sucked up into the cloud. Yes, I do mean “sucked up” as it is no longer the thermal energy from the ground that is the driving force.
So here is a practical example of condensation within the cloud causing localised winds at altitude. Maybe it is relevent to this paper and hence worthwhile looking at the subject on a broader scale. Or is a localised phenonenum not revelevent to macro meteorology?

I think my question got lost in spam because I inadvertently first posted in another discussion.

Clausius-Capeyron law:the colder the air becomes with increasing height, the less saturated water vapor it can bear.
I don’t understand this. I thought that for water vapour to condense the air had to be at least 100% humidity, and more, supersaturated and isn’t this the same to form snowflakes? Doesn’t most rain even in summer start off as ice crystals?
Water vapour in higher colder air expands and become less dense when it is doing this, displacing the air, but anyway, I thought water vapour wasn’t bothered by how cold air was, if it could get to it it could saturate it.

anna v wrote:
The ten reviewers who refused to review the publication in a sense say “I do not believe it, but I am not confident in my physics knowledge enough to refute it with a QED at the end”.
Here’s your sign.
I suspect you’re right.
I suspect the lack of confidence is well-founded.
Just because “I believe it” doesn’t mean it is. ‘Truthiness’ may work in soft sciences, but it’s not Physics.
I believe the difficulties in getting this paper reviewed say far more about the peer-review process than the paper.

Hopefully this will clear up a couple of points above where there was a bit of confusion
There are three v. d. Waals forces, 1. hydrogen bonding (water, ammonia) which is a particularly strong version of the second, 2. dipole-dipole interactions and 3. dispersion aka London forces. Dispersion occurs because of fluctuation in the charge distribution of molecules/atoms that do not have a permanent dipole moment.
Thompson measured the ratio of charge to mass of the electron by passing a beam of electrons (e/m) through a combination of magnetic and electric fields. Millikan measured the charge by measuring how fast an oil drop fell when it had a charge on it from an electron attaching. You can “do” the Thompson experiment using this applet(scroll down and select the e/m one), and the Millikan experiment using this applet.

Without going through all the comments, I still believe that winds are associated with uneven heating of the surface. Does water vapor play into that uneven heating? Maybe. At issue then is what causes uneven water vapor? Maybe it is the constant Sun hitting a somewhat chaotic oscillating cold versus warm, and choppy versus calm ocean surface. But that leads us always back to wind. So it seems to me that the cause may not be determinable, as the primary issue is a self-perpetuated system that is recharged via the Sun due to the leaky nature of the Earth’s atmospheric system.
http://www.areco.org/pdf/Global%20Winds_Jan07%20update.pdf

Thank you Dishman and Joel, I’ve done some more reading on it and I think I’m just getting a grasp of it.
Another novice question, re the paper. If winds are caused by this water induced play with pressures, has this been tracked to, say, give an explanation of winds across the Sahara?

sky
January 22, 2011 at 12:25 pm

Monsoons are perhaps the best bet for demonstrating your mechanism on a larger scale. Do you have any conclusive evidence from field measurements at that scale? And while clouds may cover roughly half the global surface at any time, that does not mean that they are being PRODUCED over a comparable area. As global satellite views clearly show, they tend to spread widely from the tropics into zones of westerly winds. Neither those winds, nor the “haboobs” that sweep sporadically across the Sahara (let alone the hemispheric dust storms on Mars) can be convincingly attributed to condensation.
I do applaud your work in elucidating a mechanism that has been sorely neglected in meteorology. But I would urge you temper your enthusiasm for its explanatory power with mature consideration of other dynamic mechanisms and the evidence from direct measurements.

Once again, thank you for your comments. I suggest that we should separate emotions (‘enthusiasm’) from scientific arguments. My colleagues and I are convinced that condensation-induced dynamics is dominant on Earth (we have not studied Mars or Venus yet) not out of enthusiasm, but because of quantitative evidence, which can be briefly summarized as follows (see the paper for details):
1) Consideration of mechanical power release associated with condensation on a global scale coincides in the order of magnitude with the observed power of global atmospheric circulation.
2) Theoretically estimated pressure gradients produced by condensation coincide with observations in both mesoscale circulation patterns as hurricanes and global scale circulation patterns as Hadley cell.
This makes us certain that future research will confirm the dominance of the mechanism we propose in generating winds on Earth. Neither wind bursts in Sahara nor breezes are global scale winds. Monsoons are, and they are accompanied by intense condensation.
Now then, when somebody puts forward a quantitative claim that condensation is unimportant, we go into details to show why such a conclusion is incorrect. Here is but one example. This demands time and involvement and we have done and are doing considerable work on this. So, when I say that I am convinced that condensation-induced dynamics is dominant, I mean all this work and all these arguments. If someone proves them wrong, I will accept that it is not dominant.
As for the human dimension — ‘enthusiasm’ — if you admit that there are two cents worth of good sense in what we are doing, you should realize that none of our findings would have never seen the light of the day had it not been for our radical ‘enthusiasm’. So, it is in the interest of all who think there is at least something worthy in what we are doing that our ‘enthusiasm’ persists rather than be tempered.

Kevan Hashemi says:
January 24, 2011 at 8:26 am
“In Section 2.3, you show that condensation occurs only when pressure drops. Indeed, that is the case. But this does not imply that water vapor increases the pressure drop.”
If a vapor condenses, doesn’t the resulting condensation exert less pressure on the surrounding system than the original vapor? I would think that the act of condensation would exert a negative pressure, actually, so for total pressure to remain approximately the same the remaining dry air would have to expand in order to make up for the pressure loss of water vapor condensation.

There are two effects: contraction due to water vapor turning into liquid and heating due to water vapor giving up its latent heat of evaporation. The heat causes the air to expand. According to my calculation, the expansion due to heating is eight times greater than the contraction due to vapor becoming liquid.

You say, “Now let the vapor ‘recall’ that it is condensable and condense. Air pressure drops immediately (remember: latent heat has been accounted for).”
If you mean that we have accounted for the latent heat by adding it before the vapor condenses, then your statement describes the contraction in volume that occurs when a vapor condenses. But if I imagine the balloon of air going up as you describe, and the vapor suddenly condensing, as in a bubble chamber hit by a cosmic ray, then the latent heat will pass into the air and warm it up, causing the gas to expand. So I’m not sure how your thought experiment refutes the effect of latent heat that I calculate in my example.
You say, “So, immediately upon condensation, there is disturbance of hydrostatic equilibrium: the air below our parcel has an uncompensated pressure to push the air parcel upward.”
If, indeed, the air contracted when condensation occurs, then it would become more dense, and it would tend to sink. You appear to be saying that that contraction in volume requires an in-rush of air, and so causes wind. But the contraction is of order 0.1% (in my calculation), and can be accommodated by a 0.1% expansion of nearby air. Once that’s done, the contracted air in your thought experiment would be more dense, and would fall.
But that’s not what happens. Instead, the air in which water condenses appears to rise. According to my calculations, it rises because it is less dense, and it is less dense because it has expanded after receiving the latent heat of the water vapor. It begins to rise, and it keeps rising, and that causes wind.

I didn’t mean to ignore Eli Rabett’s introduction of Van der Waals forces to the intermolecular force kit. I had deliberately removed the charged droplet case to simplify the situation so that cloud Electric fields, didn’t get into the water droplet support. We used to fly Hydrogen inflated weather radiosonde balloons up into boomer storm clouds with custom apparatus on it, to actually monitor the electric fields under storm clouds. This was back when graduate students were cheap and naive; and indestructible.
But Eli of course is correct that VdW forces of the several species can also supply support to a raindrop. That doesn’t really change anything though. As a result of providing the levitation; be it through collision and rebound or VdW forces, the result is a downward reaction on the atmospheric molecules; which must manifest itself at the boundary (ground) as an increase in pressure; that being the necessary pressure to sustain the total mass (and weight) of the water droplets. So it is still not clear to me that mere condensation of water vapor into a droplet will drop the atmospheric pressure (or increase it). And of course as Anastassia points out the latent heat is a different issue. The condensation takes place as a consequence of the loss of that latent heat energy, so it seems to me that in the act of “condensing”, there isn’t a sudden heat surge. But any net change in the energy can be accommodated by the ordinary gas law equations of state.
The mass of the water molecules must be supported by the atmosphere whether as individual free molecules or some condensed state; they still have to be supported, and must produce a pressure increase (due to their presence).
The whole process may be fully explained by Dr Makarieva’s team or not. I just don’t have the gist of it yet; but am not arguing against their thesis.

Kevan Hashemi says:
January 24, 2011 at 11:21 am
“If, indeed, the air contracted when condensation occurs, then it would become more dense, and it would tend to sink. You appear to be saying that that contraction in volume requires an in-rush of air, and so causes wind. But the contraction is of order 0.1% (in my calculation), and can be accommodated by a 0.1% expansion of nearby air. Once that’s done, the contracted air in your thought experiment would be more dense, and would fall.”
It should be easy enough to test in a home refrigerator. Blow up a few balloons (warm, moist air) and stick them in. If water condensation does indeed result in a net pressure increase then you should see the balloons gradually deflate as they cool off, expand when the air inside the balloons hits the dew point, then deflate again as cooling proceeds. With breath near 100% humidity you won’t have to wait long for the expansion event (if any) – the air in the balloons only has to drop a couple of degrees before it hits the dew point (at sea level).

Correction: We always have pressure decreasing as volume INcreases.

Anastassia Makarieva.
I’d have liked to have responded earlier to you post, but social disciplines have prevented this.
I’ve spent ~4 hrs reading your paper and responses here (I don’t ‘speed read’ too well when it comes to reading tech stuff), and one thing becomes ‘blatantly’ apparent! I don’t see any inclusion of ‘Earth spin’ energy in your paper (or in ‘climate models’ either).
OK, so I’m just an engineer with an interest in climate change, but it becomes apparent to me that you are ignoring the effect of Earth’s rotational slow down following the ‘alleged collision’ with Thea that both accelerated Earth’s rotation and formed ‘the Moon’ way back.
The ‘centrifuge effect’ imparted by Earth’s rotation supplies most of the energy at the equatorial ICG to supply the Hadley Cell with all the energy that it needs for it’s circulation (I calculated this to be more than ‘3 inches per second squared’ in counterpoise to the gravitational constant). However, IMHO, I think that your paper may well describe the ‘extra’ energy that supports the Brewer-Dobson circulation to some degree.
But, hey. I’m just an engineer!
Best regards, Ray Dart.

“”””” Kevan Hashemi says:
January 24, 2011 at 3:01 pm
Mr. Smith,
Your description of electrostatic force being able to support water droplets is fascinating. I will have to think about it more, because I don’t yet understand it, but it certainly adds a new dimension, because that means that the charge will keep building up where the water is condensing, as the air rises through the cloud-forming layer. “””””
Kevan, when I talked about “somebody” supporting the water droplets, I of course was assuming the non-precipitating case (it ain’t rainin yet), so I assumed that the water droplets were still small enough to be supported. Now Dr Makarieva pointed out that the droplets are supported by upward mass air flow. So that is a macro view, and as she said the droplets are actually falling through that upward air flow at the terminal velocity. So in the macro view you have to consider Reynold’s numbers and the like but for small enough drops I think it is safe to assume a non turbulent laminar flow around the droplet. Someone mentioned friction forces, and I suppose in a sense you could call the interface forces a friction. Eli points out that VdW forces are acting between molecules. Some of those result from the dipole nature of the water molecule; so even though the droplet may have a net charge of zero, so that it is not subject to any local electric fields perhaps due to charged clouds, there can still be local electric forces due to molecular dipoles. As I recall it is usual for molecules to repel each other somewhat, which is why you get the small pressure adder term (b) in the Van Der Waals equation of state.
All of these kinds of forces the surface “friction”, viscosity shear (in the atmosphere) as well as the microscopic molecular level collisions, are all acting in concert to suspend the water droplet or raise it through the air column, till it get heavy enough to precipitate.
My point is simply, that whatever forces of any nature (besides gravity) are acting to support the water droplets, those forces must result in a net downward force on the atmosphere that simply is the weight of the droplet (unless it is accelerating too) so the weight of the water must still provide a pressure adder; and it isn’t clear to me, why that would be different from that supporting the water as a vapor.
Now we can imagine a closed vessel containing air (even water) on the space station; so now we have removed gravity; and I doubt that anything much has changed inside that closed vessel. So of coursae the gas pressure remains as it was, due to the kinetic energy of the molecules, and that includes the partial pressure of the water vapor. Now in this case, if the water vapor condenses, then my gravitational factor doesn’t come into play.
Now I’m curious as to just what the Makarieva Effect would do in that case. So if we still have the good Doctor’s attention, she might comment, on what happens in zero g. Or is her result a consequence of gravity; so no show in zero g.
As to the suspension by electric fields; that of course is what Milliken did; but he used a low vapor pressure oil so he wouldn’t have his droplets evaporating. The droplets are sprayed into the gap between two capacitor plates, which can be viewed from the side through a long focus microscope. You let the droplets fall, with no electric field, and they reach terminal velocity which you can time over a trap distance; or today you could have more sophisticated speed reading. From the terminal velocity and the density of the oil, you can derive the mass and weight of the droplet. You then turn on the field, and if the droplet has collected any electrons, the electric field can support the droplet and hold it still. Uncharged droplets will simply drop out of the way. The experiemtn depends on the fact, that the droplets are so small, that you can find droplets with just a single electron extra. Of course Millikan obtained a number of different charge values based on the electric field strength necessary to levitate each droplet; and of course they turned out to be integer multiples of a single value. He did get droplets with a single electron charge; I did too when I did it in school. Lots of people tried refined versions of the experiment, hoping to find charges of -1/3 or -2/3 thinking they could detect a free quark. All of those experimenters are buried in the same cemetary, as the Optician who tried to polish out #80 grit pits with Jewellers rouge; old age it says on their death certificates.

Dear Kevan
For some reason, I cannot see here your comment that has just arrived to my mail box. I reproduce it below:

Dear Anastassia et al.,
Consider your Equation 1. Substitute for dT using RdT = pdV + Vdp. Assume dQ = 0. I’ll use w for the mass of water dissolved in 1 kg of air, so R is 287 J/Kkg, C is around 1 kJ/kgK, and L is 2 MJ/kg.
dp = -(1+R/C)pdV/V – RLdw/VC
In dry air we have dw = 0, and we are left with the derivative form of the adiabatic expansion equation. When water condenses we have dw < 0. Thus dp will be less negative than it would be for dry air.
When 1 g of water condenses at 100 kPa and 300 K, its volume contracts from 1 liter to 1 milliliter. Your Equation 1 does not account for the contraction of the water vapor. Your Equation 11, derived from Equation 1 and Equation 3, does not account for the contraction of water vapor either. The apparent relationship between dp and dw in Equation 11 is the slope of the coexistence line on the p-T graph for water.
The contraction due to water turns out to be insignificant compared to the latent heat, as I have already shown.
Yours, Kevan

Your conclusion that condensational mass removal is insignificant is based on consideration of the buoyancy of a given air parcel. Your point is that if we raise this parcel sufficiently high, it will be much warmer than the dry air parcel would have been — had we raised it to the same height. This is due to the well-known difference between the moist and dry adiabatic lapse rates.
Air density (kg/m^3) rho = NM = pM/RT, where N is molar density (mol/m^3), M (g/mol) is molar mass, p is air pressure, R = 8.3 J/mol/K, T is temperature. What you propose is that when you raise your air parcel to sufficient height h = 8 km, the difference between moist adiabatic lapse rate (about 4.5 K/km) and dry adiabatic lapse rate (9.8 K/km), will amount to over 40 K. At T ~ 250 K your point is that this makes a solid impact on density and, hence, buoyancy. If pressure is the same, a comparative increase in temperature of 40 K raises buoyancy by about 20%.
Now looking at rho = NM and recalling that the saturated Nv makes at best 4% of N at the surface, you conclude that the maximum impact of vapor removal on buoyancy can amount to a few per cent, which is much less than the dozens per cent that you calculated from temperature differences due to latent heat release.
These calculations of buoyancy are totally irrelevant though to condensation-induced dynamics. As I said above, in order that buoyancy effects to be significant, there must be a horizontal temperature gradient. There must be air with buoyancy smaller than that of moist air. If the vertical temperature gradient is spatially uniform, warm or cold, the air will not move.
So, let us forget about buoyancy and concentrate on the new physics: you raise moist air parcels over an infinite area: at any height the temperature, pressure and buoyancy are the same. But, due to condensation, partial pressure of vapor changes non-hydrostatically: dpv/dz = -pv/hv, where hv is much smaller than the hydrostatic equilibrium height h.
Hydrostatic equilibrium is disturbed. The pressure gradient force that arises is equal to -[dpv/dz – (1/pv)dp/dz] = pv (1/hv – 1/h). This force acts throughout the entire column where the moist saturated air ascends. It accelerates the air upwards. Due to the fact that the height is smaller than width, hydrostatic equilibrium is restored much quicker in the vertical plane — some air from the surface moves upwards to fill the gap left by condensed vapor. In the result, pressure is lowered at the surface where condensation takes place.
As I said above, the comparison of the maximum possible effect of latent heat release on pressure versus condensational mass removal effect on pressure is given in Fig. 1c of our paper. This figure grossly overestimates the effect of latent heat release, because it assumes that there is no heat exchange between the columns. In reality there is never such a huge difference between the areas where the air ascends and where it descends because of large turbulent mixing.
Eq. 1 does not and cannot say anything specific about condensation-induced dynamics, because it contains the amount of condensed vapor, dq, as an independent variable. This equation does not tell anything about buoyancy either. This is because it is the first law of thermodynamics. For a given dV, you are right, pressure will fall less when there is condensation. For a given dT, it is easy to see that the opposite is true. These thermodynamic considerations do not teach anything though about the dynamics: namely, the appearance of non-equilibrium pressure gradients that make the air move.

Anastassia:
Thanks for your detailed response. I will read it a few times to make sure I understand it. Will answer in when I think I have something worth saying.
Steve:
You say, “No transfer of energy occurs between the water and surrounding air, yet there is condensation.” I think that’s incorrect. Whenever water condenses, we get back the heat we had to put in to make it vaporize. I think that’s why steam burns are so nasty when compared to hot-air burns. The steam, when it condenses, gives up 2 MJ/kg.

Anastassia Makarieva says:
January 24, 2011 at 9:42 am
Steve
January 24, 2011 at 9:24 am
If a vapor condenses, doesn’t the resulting condensation exert less pressure on the surrounding system than the original vapor? I would think that the act of condensation would exert a negative pressure, actually, so for total pressure to remain approximately the same the remaining dry air would have to expand in order to make up for the pressure loss of water vapor condensation.
Exactly. This is why the cloud sucks in the surrounding air, as Jantar said above. Since condensation occurs as the air moves upwards and cools, the resulting pressure gradient force is also upward directed.
—
Anastassia, fine article. And Jantar, great to have another sailplane pilot here.
Jantar here gave a great description of that experience. Many times just below the cloud base your variometer needle will be pegged at 1200 ft/min upward and you start counting seconds compared to the spinning altimeter to try to gauge your rate of climb, sometimes 1800 to 2400 ft/min. You only have seconds to respond.
But the real experience of condensing water vapor is to stand on your own patio and watch a tornado form over your house. It’s always on very warm day with stifling humidity. You look up at the dark base and start to see some very thin angle hair white clouds some 500 feet lower, always white compared to the cloud above. You start to feel the warm moist wind at your back as these wisps appear and disappear and they look so innocent. As they to start to appear and stay longer you notice a very slow rotation, not fast, just 5 r.p.m. at best. Winds still getting stronger. This whole process is within a few minutes. You now see they are persistent with a definite rotation and its faster, more are now forming even lower, these what I call white whisps… Go get in the closet.
These angel hair clouds are condensation occurring lower and lower and closer to the ground and the suction is awesome. Just look at some pictures of the vortexes filmed during the California forest fires last year. Those are thermal, 1000 deg+, vortexes and though looking impressive with the fire they are but as tiny dust devils compared to tornadoes. It’s the moisture and condensation people, not the heat, heat has it’s effect and usually in the same direction but the force from condensation is much greater.
And I have to believe this same process happens over large regional areas also, frontals. So what is the cause and what is the effect when it comes to pressure variance? Seems this paper has it right.
Anastassia, keep up the work, I love science when it finally, over years of misinterpretation, ends up correct in the end. That is why I have always read so many scientific papers for many, many years.

Anastassia
January 25, 2011 at 9:28 pm
Thank you for some good links. I’ll read them all. And i think you see that I really do understand your groups theory, I understand it not from the science and math side but because I have many times actually experienced it in the real world. That is where I say stay with it, it is real, whether science wants to currently listen or not. Thermal has been the standard answer for so long and it’s hard to change consensuses.
So you want to see a tornado huh, just come to Oklahoma in late spring for a week or two. I’ve even heard you can now get special storm-chaser tours, don’t wait for one to come to you, go chase one down!
However, there is one aspect I don’t understand yet and I haven’t been able to completely absorb the paper. In the summer here there are many days with clouds (condensation) floating across the sky, building and dissipating, day after day, never raining, and the moisture is just being recycled over and over. As I spoke of sailplanes there is tremendous convection happening under these large clouds always but that is all very local wind in nature. It seems just by intuitive logic that until it does actually rain and liquid water is removed from the system in large quantities that the effect stays local. But with heavy rain I can then see the horizontal aspect you spoke of, the paper thin atmosphere compared to the horizontal plane. Is that the only time when it then becomes regional (500-1000 km) in nature, when rain/ice/snow is removed?

Steve
January 25, 2011 at 11:47 am

By “maximum possible effect”, does the figure assume that 100% of atmospheric condensation is the result of latent heat release to the surrounding air? Wouldn’t the figure then be grossly, grossly overestimating the effect of latent heat release? I understand that convective and radiative heat transfer of some magnitute is always occuring, but isn’t the lion’s share of atmospheric condensation adiabatic?

When we speak of adiabatic condensation this means that the latent heat released upon condensation remains within the air parcel where condensaton occurred. Strictly speaking, liquid water should also remain there — when it is removed we have what one calls pseudoadiabatic process.
In our Fig. 1c two atmospheric columns are compared, both are in hydrostatic equilibrium. But in one column the lapse rate is moist adiabatic (column A), while in another one it is dry adiabatic (column B). Surface temperatures are the same, so at any given height the air in column A is always warmer than the air in column B.
The second difference is that the amount of vapor in column A is smaller than in column B by the amount that is necessary to make the lapse rate in A moist adiabatic (to do so, we do need to condense some vapor throughout the column). So surface pressure (and total amount of gas) in column A is smaller than in column B.
One can see from Fig. 1c that below the height zc where pA-pB = 0, the effect of mass removal dominates and the air pressure is lower in column A. Above zc, the temperature difference (the one Kevan was talking about) plays finally in, such that the warmer air in column A has higher pressure than in B above zc.
What is meant by ‘maximum effect’ of latent heat: this means that there is no heat conductivity between the column, such that the temperature difference between them amounts to over 40 K at a height of several kilometers. In reality this never happens: due to strong horizontal mixing, the ascent is not adiabatic. Latent heat is at least partially removed from the air parcel where condensation takes place. It is lost by radiation to space and by turbulent mixing to the descending column which is being warmed. Actually such circulation pumps the latent heat from the condensation area to the surface of the area where the air descends. This was happening for over two months this summer during the heat wave in Russia.

George E. Smith
January 25, 2011 at 10:11 am

My point is simply, that whatever forces of any nature (besides gravity) are acting to support the water droplets, those forces must result in a net downward force on the atmosphere that simply is the weight of the droplet (unless it is accelerating too) so the weight of the water must still provide a pressure adder; and it isn’t clear to me, why that would be different from that supporting the water as a vapor.

The difference lies in the fact that in order to support droplets the air must move upwards — if we are talking of a stationary pattern. In order for the air to move, there must be a non-equilibrium gradient of air pressure. Considering one dimensional motion, if the pressure gradient force is balanced by the downward force associated with droplet friction. That is, a microscopic pilot riding on the droplet will serve as a brake for the upward air flow in very much the same manner as windmills, for example, serve as a brake for the horizontal air flow. In its turn, the upwelling air will be pushing the droplets upward as the horizontal air flow is pushing the windmills.
In contrast, no air flow is needed to sustain vapor molecules in the atmosphere. The air is static.

Now we can imagine a closed vessel containing air (even water) on the space station; so now we have removed gravity; and I doubt that anything much has changed inside that closed vessel. So of coursae the gas pressure remains as it was, due to the kinetic energy of the molecules, and that includes the partial pressure of the water vapor. Now in this case, if the water vapor condenses, then my gravitational factor doesn’t come into play.

I agree, it does not.

Now I’m curious as to just what the Makarieva Effect would do in that case. So if we still have the good Doctor’s attention, she might comment, on what happens in zero g. Or is her result a consequence of gravity; so no show in zero g.

My colleagues and I very much value the readers’ attention. It is a pleasure to share our thoughts. Zero g is a very interesting case.
Condensation occurs because the temperature drops with height. When we have gravity, this happens any time when the air ascends because of expansion. Let us put g = 0 and consider an atmosphere in a closed container. A vertical temperature gradient can form due to the greenhouse effect. Also, we can just impose it externally on our atmosphere by some technological device. This will lead to the appearance of a non-hydrostatic pressure gradient and air motion.
The latter case is realized in practice in heat pipes. These are technological devices that employ the pressure gradient of the saturated vapour to effectively transfer heat. The rapid transport of heat along the pipe is due to the difference in partial pressures of saturated vapour within the pipe. One end of the pipe is warm (attached to the body that we have to cool), another is cold. Vapor pressure is high where it is warm and low where it is cold. This pressure gradient causes the vapour to flow very rapidly along the tube from the hot end to the cold. The theoretical limit of flow velocity is, obviously, the velocity of molecules. This makes heat pipes very efficient coolers.
However, in heat pipes one must artificially remove the latent heat from the colder end of the pipe (otherwise the temperature gradient responsible for the vapor motion will disappear). This is a limitation on the pipe performance. Likewise, in an atmosphere with g = 0 and a temperature gradient due to absorbers of thermal radiation, the limitation is that the released latent heat must be ultimately radiated to space. That is, if you want to have a larger air velocity, you must radiate more efficiently.
Atmosphere with gravity is unique in that there is an adiabatic temperature gradient that persists in the region of ascent irrespective of how large the vertical velocity is. There is no problem of disposing heat (the process is adiabatic yet the temperature drops) to maintain the temperature gradient that is needed to sustain condensation. This allows for a positive feedback between velocity and condensation: the larger the vertical velocity, the larger the condensation rate S, the larger the pressure gradients associated with condensation (see Eq. 37 in M10), and so on. Such a positive feedback would be absent at g = 0.

Anastassia Makarieva says:
January 26, 2011 at 6:28 am
“When we speak of adiabatic condensation this means that the latent heat released upon condensation remains within the air parcel where condensaton occurred….What is meant by ‘maximum effect’ of latent heat: this means that there is no heat conductivity between the column, such that the temperature difference between them amounts to over 40 K at a height of several kilometers. In reality this never happens: due to strong horizontal mixing, the ascent is not adiabatic. Latent heat is at least partially removed from the air parcel where condensation takes place. It is lost by radiation to space and by turbulent mixing to the descending column which is being warmed. Actually such circulation pumps the latent heat from the condensation area to the surface of the area where the air descends. This was happening for over two months this summer during the heat wave in Russia.”
In your statements I don’t see where you explain that at least some energy in latent heat is expressed as work, not heat, on the surrounding air during an adiabatic cooling process. The temperature of the ascending air mass goes down without any increase in temperature to adjacent air masses, just energy expressed as work, but at the moment of condensation suddenly there has to be a heat transfer between the water vapor and the surrounding air? Every joule (or most) ends up as released heat right then and there at the moment of condensation? If so, I don’t think that I am ever going to understand this adiabatic atmospheric process.
It seems like you are treating “latent heat” as a special kind of energy that, during adiabatic atmospheric cooling, acts differently from all of the other energy in the air mass. The temperature of the water vapor goes down without any heat exchange between the water vapor and surrounging air mass, just an energy exchange in the form of work. But this work is not an adequate energy exchange to allow water to condense without a significant heat exchange? I don’t understand why the energy exchange needed to achieve condensation cannot also be expressed as work on the surrounding air instead of heat.

Steve:
“The temperature of the ascending air mass goes down without any increase in temperature to adjacent air masses,”
That’s not true: the adjacent air masses warm up. The ascending gas compresses the descending gas. The descending gas heats up.
“just energy expressed as work”
The work done by the expanding gas turns into heat and pressure energy in the adjacent gas.
“but at the moment of condensation suddenly there has to be a heat transfer between the water vapor and the surrounding air?”
Absolutely, at that very moment.
“Every joule (or most) ends up as released heat right then and there at the moment of condensation?”
Yes, every Joule.
“If so, I don’t think that I am ever going to understand this adiabatic atmospheric process.”
Indeed: if what you said was true, nothing would make sense. But I hope that what I say holds together.
“I don’t understand why the energy exchange needed to achieve condensation cannot also be expressed as work on the surrounding air instead of heat.”
If you start thinking it through again, I hope you won’t get to this question. There are several answers. To start again, you could try this simple explanation of convection:
http://homeclimateanalysis.blogspot.com/2010/04/convection.html
To see why some gas has the energy to compress other gas, and thus cause circulation, see the p-V diagram here:
http://homeclimateanalysis.blogspot.com/2010/04/work-by-convection.html
And after that you will be able to explain to me how a jet engine works.
Yours, Kevan
PS. I still have not been able to understand Anastassia’s recent explanation of the condensation-suction process. I am still trying.

Anastassia Makarieva says:
January 26, 2011 at 10:19 am
wayne

However, there is one aspect I don’t understand yet and I haven’t been able to completely absorb the paper. In the summer here there are many days with clouds (condensation) floating across the sky, building and dissipating, day after day, never raining, and the moisture is just being recycled over and over. As I spoke of sailplanes there is tremendous convection happening under these large clouds always but that is all very local wind in nature. It seems just by intuitive logic that until it does actually rain and liquid water is removed from the system in large quantities that the effect stays local. But with heavy rain I can then see the horizontal aspect you spoke of, the paper thin atmosphere compared to the horizontal plane. Is that the only time when it then becomes regional (500-1000 km) in nature, when rain/ice/snow is removed?

This is a very interesting question. Note also that it resonates with the comment of Dr. Judith Curry (the only reviewer so far of our work):

I disagree with the authors regarding evaporation vs. condensation. They identify
“salient differences” between them which in fact do not exist. Evaporation is not a
surface specific process. When a cloud forms in the atmosphere, the condensed
water has one of two fates: fallout in the form of precipitation or evaporation. The
precipitation efficiency of clouds is rather low, much less than 10%. So most of
the condensed water in the atmosphere eventually evaporates in the atmosphere.
But I don’t see that this has much impact on their overall argument.

When vapor condenses, the air pressure is lowered. When moisture evaporates, air pressure rises. If we see a constant amount of cloud water but no rain, this means that this process is localized in the atmosphere on a small scale: condensation occurs in the region of ascent where the cloud resides, evaporation (of condensed droplets) occurs in the region of descent, where relative humidity is less than unity. This may result in the formation of regular patterns like cloud streets.
When is this possible? It should be possible when the droplets that are formed are sufficiently small (have high surface to volume ratio and low terminal velocity) and the circulation velocity is sufficiently low. Only in this case the droplets will have time to evaporate before reaching the surface. One can hypothesize that such a regime is unstable: if vertical velocity increases and/or droplets get larger, they are removed more quickly from the atmosphere across a larger area. The balance evaporation – condensation = 0 in the atmosphere is then broken in this area and it becomes a large scale area of low pressure.
But note also that persistent clouds without rain may also represent a non-stationary accumulation of liquid water in the atmosphere: in this case, the entire area with clouds gradually becomes the low pressure area despite there is no rainfall.
It would be great if climate scientists, many of whom do find time to do blogging and may even happen to read this thread, would join the discussion of condensation-induced dynamics. There is much to discuss here. It is beyond doubt that having got acquainted with the main propositions, people will be able to use them to explain many weather and climate patterns of which we may have little or no knowledge at all.
— —
You know, after asking that question of you I had some secondary doubts on my own question.
If there is any condensation, this effect of lowered pressure is going to happen regionally whether there may also be local effects or not. Stratus clouds may not even have a local effect. Cumulus always do due to the clumps. But you know, both local and regional is always happening at the same time, it is never really just local. When clouds form, like after a clear night, that IS the condensation even though the droplets are not large enough to fall in participation. Thinking of that it doesn’t seem to matter if 1 cm3 of water has condensed to form 21 raindrops or 10,000 tiny particles forming the mist from which clouds are made.
The condensation has already occurred.
And if you imagine yourself raised up high in the atmosphere and look down (as in a plane) you see condensation has occurred everywhere, maybe enough to cover an entire state or more. That suction would then be horizontally. You would see individual clouds dissipate but there would always be another to take it’s place and the over all effect would be lower pressure compared to the cloudless night a few hours before. Most importantly, that would seem to make the atmosphere as a whole pulse every diurnal period as the clouds of that type normally disappear every night, reform the next day. There is something I had never thought of in that way.
That made me reconsider my whole question, what exactly was I asking you. Sure didn’t want to infer something that would lead to a thought that wasn’t real, like: If it doesn’t fall to the ground as rain there is no effect for now I see it does. Seems if it does participate that just adds permanency to the effect. Kind of like a closure of a single event. When precipitating, the effect is no longer a one-time event but a continuous force laterally as long as the water is falling out.
I see it now. (if not, please clarify) Don’t you love it when you are able to think in an entirely different direction that just yesterday you thought was so perfectly logical and in reality was so wrong. That’s exactly why I follow science as a hobby!

Kevan Hashemi says:
January 26, 2011 at 11:49 am
“Steve – The temperature of the ascending air mass goes down without any increase in temperature to adjacent air masses…Kevan That’s not true: the adjacent air masses warm up. The ascending gas compresses the descending gas. The descending gas heats up.”
So because the expanding, rising volume is doing work on adjacent air volumes (moving them by applying pressure), those adjacent volumes must be heating up from the pressure increase? Well, if the pressure is applied to a gas that remains in the same volume, yes I can see how the temperature must increase (ideal gas law). But if the pressure is applied and the gas simply moves (wind)? Are you saying that in adiabatic processes there really is a heat transfer, it’s just in the form of work that is immediately translated into heat?! That would be confusing. Why don’t they just call it a heat transfer?
“The work done by the expanding gas turns into heat and pressure energy in the adjacent gas….If you start thinking it through again, I hope you won’t get to this question. There are several answers. To start again, you could try this simple explanation of convection: http://homeclimateanalysis.blogspot.com/2010/04/convection.html”
Hmmm, the explanation at that link doesn’t really help me. In it you state,”In short, we assume that any heat the Volume loses or gains on the way up is negligible. The expansion of the Volume will be adiabatic. As a gas expands adiabatically, it cools down, even though it loses no heat.” That statement doesn’t make sense to me. It cools down but it loses no heat? It most certainly does lose heat or it would be the same temperature! What it doesn’t do is transfer heat – it transfers energy. I understand that at some point somewhere all that energy will end up as heat, but that could end up being far away in time and space. For example, a helium balloon that rises to great altitude and lands on a mountain will have some portion of it’s original internal energy stored as potential energy as long as the mass of that balloon remains on that mountain. Adiabatic expansion is completely new to me, so I have no idea how long it takes for the work of moving an air mass to be expressed as heat, and how far away from the expanding air mass this work will be expressed as heat.
Kevan Hashemi says:
January 26, 2011 at 11:56 am
“Steve: I noticed another comment above from you. You say that when water condenses, some of the energy we put in to vaporize it can manifest itself as work. No, it can’t. That would violate the Second Law of Thermodynamics, which says that you cannot make a machine that is 100% efficient at converting heat into work. All it takes to vaporize water is heat, so if I can get work out of the act of condensation, I’d be able to start again by adding heat, and so build a cyclic machine that creates work.”
As I said to Anastassia, it seems like you are treating latent heat as a special kind of energy. Which may be true, I’m just looking for the “how”! Adiabatically, the energy of the rising water vapor can be transferred to the surroundings as work, except for the energy of it’s latent heat?
Hmmm. You don’t have a problem getting heat out of condensation, but if I say “work” (same units, joules) suddenly I’ve invented a perpetual motion machine? I don’t expect a 100% return in the form of work, which is pretty clear since you quote me as claiming “some of the energy we put in to vaporize it can manifest itself as work.” According to you, 0% of the latent heat can be transferred as work (“No, it can’t.”). How is that?

Retired physicists who might help:
Hal Lewis
Freeman Dyson

Kevan Hashemi says:
January 26, 2011 at 4:36 pm
“You say, “It cools down but it loses no heat? It most certainly does lose heat or it would be the same temperature!” Well, the word “loss” in thermodynamics means something irreversible. In adiabatic expansion, internal heat is turned into work and work only. No heat is “lost”. When heat is converted into work, it is not “lost”. We can convert it back into heat any time we want. Only when heat flows out of our system do we say it is “lost”. Or at least that’s how I was taught to use the word.”
Ahhhh, I didn’t know about “loss” terminology. An energy transfer within two components of the system is not referred to as a “loss” by either component of the system – got it.
“Condensation results immediately in faster-moving molecules, which is heat.”
As state changes from gas to liquid to solid, the molecules have less kinetic energy, not more. What are the faster moving molecules – the air adjacent to the condensation?
“If we say that condensation energy is converted directly into work, we are glossing over the fact that some other component is required to cooperate with the conversion of heat into work. In this case, what is that component?”
Again, I’m not following how the latent heat transfer (as work) is any different from all of the other energy transfer in an adiabatic process.
I’m a visual thinker, and I imagine a hornets nest of air molecules pushing out as their mass rises. This pushing, ascending in altitude, is work and lowers the kinetic energy of every molecule in the air mass (i.e., the temperature of the air mass drops). Considering that the potential energy of the mass is increasing as it lifts itself through the atmosphere, it isn’t surprising that something has to give. Those molecules can’t do work, get an increase in potential energy, and keep their original kinetic energy! Within this air mass are water molecules that are losing their kinetic energy while still colliding with each other. Eventually the collisions lack the energy necessary to overcome the attractive power between the water molecules and they stick together – we have atmospheric condensation. (That’s simple condensation – a cloud nuclei, such as a bit of dust, is more likely to serve as the condensation surface.)
I understand that some of the temperature drop in the air mass will be due to heat exchange with adjacent, colder air masses. Cooling will not be 100% adiabatic! But what adiabatic cooling there is, to my understanding, is work, not heat transfer. That air mass climbed a mountain! I don’t see how it can be assumed that condensation results in a temperature increase to adjacent air masses that is equivalent to 100% of the energy of latent heat.
“I’m saying that air with moisture will be warmer as it rises, so it will expand and be less dense. Now it will rise above the dry air, like your balloon to the top of a mountain. That’s work. But we needed the dry air to make the conversion possible.”
I understand that. My confusion commenced when you stated that the transfer of latent heat at condensation would cause expansion of adjacent air that was 8 times the magnitude of the compression experienced when the water vapor condenses. I took that to mean that as warm air rises you suddenly get a burst of positive pressure when the dewpoint is reached. That seemed off (I expected a negative pressure), so I had to research this adiabatic cooling process.

Steve,
I agree with your description beginning “I’m a visual thinker.” Furthermore, I can perfectly see how “I took that to mean that as warm air rises you suddenly get a burst of positive pressure”.
But what I meant was that adiabatic expansion of dry air from V1 to V2 where V2 > V1 gives a greater pressure drop than adiabatic expansion of moist air. The latent heat causes the air molecules around the water droplets to buzz around more rapidly.
If we have a 1-km wide body of air, we can imagine that the heat transferred by mixing, conduction, and radiation across the boundaries of the body will be negligible compared to the work done by the gas in expanding and rising. I assume you agree with that. If so, then you’ll see that the ideal adiabatic expansion equation is useful in understanding how the gas cools as it rises.
We can arrive at the effect of latent heat upon the gas in several ways, and one of the simplest is to imagine the gas expanding adiabatically (no heat transferred by conduction, mixing, or radiation) to a certain volume and pressure, and then we calculate the effect of condensation upon the pressure, even though we know that this condensation would occur during the expansion, not at the end. The net effect is positive: condensation raises the pressure compared to that of dry air.
In Anastassia’s paper, it seems to me (and recall that I still don’t understand her most recent explanation, so I could just be ignorant) that the authors are confused by the fact that condensation occurs only when pressure drops. They take this to mean that condensation causes a pressure drop, when in fact condensation reduces the pressure drop.

Kevan Hashemi says:
January 27, 2011 at 12:43 am
Steve,
I agree with your description beginning “I’m a visual thinker.” . . . .
Laurie says, . . . . .that’s why graphs and diagrams are good. They are worth a thousand words.
http://en.wikipedia.org/wiki/File:Water_cycle.png

It’s been a busy week so I’ve not had time to follow this discussion in detail or to respond to Anastassia’s comments.
I left the discussion after she mentioned the simple model of a flat, isothermal Earth (to which I narrowly avoided quipping that that’s how many climate modellers see it). But I was reminded of the (classic) conditions for natural (free) convection in a compressible fluid (without phase change); and the heat transfer within. To date, this thread hasn’t mentioned Grashof, Prandtl or Nusselt.
Free convection is due to body forces; those due to gravity.
Forced convection is due to surface forces; those due to fluid pressure, exerted “mechanically” from “outside”.
The Grashof number is the ratio of buoyancy to viscous force.
The Prandtl number is the ratio of momentum to thermal diffusivity.
The Nusselt number is the ratio of convective to conductive heat transfer.
There is no free convection until the Rayleigh number (Gr.Pr) exceeds a threshold. All heat transfer is conductive below that threshold. (Radiative heating is insignificant near the surface when compared to conductive and subsequent convective.)
For free convection to occur, it is only necessary for the buouyant forces to overcome the viscous and gravitational ones; by thermal (conductive) expansion of the fluid.
It is not necessary for (part of) the fluid to undergo any phase change for free convection to occur. If it does; does warm air rise above a fog in calm conditions?
As a final short note: The Earth’s surface is far from an isothermal plane. It has vast thermal gradients that change with time.

Brian H says:
January 27, 2011 at 12:18 am
wayne & steve;
you’re both trying to imagine what happens, and failing. 100% of the latent heat is transferred to the surrounding molecules. A window pane that condenses water vapour is warmed by that process. Air temperature cannot drop below the “Dew point” because condensing the dew dumps heat into the air, until humidity is lowered to the point that the dew point also drops. And so on.
———
Brian, you might re-read my comment giving Steve a few questions to think about. Latent heat until condensing begins is potential, or are you saying you disagree?

Kevan Hashemi says:
January 27, 2011 at 5:01 pm
“Steve, you say, “I’m still trying to figure out the mechanism by which this heat is physically transferred to the surrounding air – conductive? radiative?”…… I tried to answer that question in my second comment tonight. Did you see my description of how a water molecule becomes bound to others, as a result of statistical chance, and how it might escape. If you stick to your buzzing molecule picture, it will all work out.”
I did see your explanation, but as soon as I read “A water molecule condenses when random encounters with other vapor molecules leave it almost stationary and not vibrating” I lost understanding. Water is still condensed as 99 C on my stove. That is a lot of kinetic energy – those condensed water molecules are most certainly moving and vibrating! Why must this be different for a gas? “Almost stationary and not vibrating” sounds like “almost absolute zero” to me, and the water vapor in a cloud is well above that temperature.
I did more of my own research and it looks like my question, “Is it a pseudo-chemical bond in which radiative heat transfer must occur?” points to the correct answer.
I know about hydrogen bonds but I didn’t realize they resulted in more stable electron configurations. They are pseudo-covalent bonds. Read this from 1999:
http://www.sciencedaily.com/releases/1999/01/990121074852.htm
At vaporization, energy breaks these hydrogen bonds, leaving the individual water molecules with all electrons in their “standard” covalent bonds. At condensation hydrogen bonds reform at an average of 2 – 3.6 hydrogen bonds per water molecule, depending on conditions (and experimentally there is some debate). As with any electron moving into a more stable covalent bond, some energy must be radiated immediately as a photon.
I think that kinda answers it for me. At condensation there will an immediate radiation of heat commensurate to the energy of the hydrogen bonds formed. So condensed air must indeed transfer latent heat into the atmosphere at the moment of condensation. Not during it’s ascent. Not when the water hits the ground. But the instant those electrons go to a lower energy state.

Steve:
Yes, the reason liquid water molecules are hard to separate is because of hydrogen bonds. But you end with, “At condensation there will an immediate radiation of heat commensurate to the energy of the hydrogen bonds formed.” Absolutely not. Who said anything about radiation? You made that up yourself. Nothing is radiated. The reason the gas gets hot is because of the statistical reason I gave you: only when a water molecule is deprived of most of its kinetic energy by random collisions can it be bound to another water molecule. You can figure all all this out in terms of molecules bouncing around. It’s as simple as that. That’s Statistical Mechanics, and it works fine. There is no radiation involved. Why do you want to make it more complicated?
As to “water at 99C” being hot, well, that’s true. But what do you mean by “hot”? Two bodies are at the same temperature when they exchange no heat. That does not mean that they contain the same amount of heat per kilogram or per atom. Water contains far more heat per kilogram than iron at the same temperature. Steam contains far more heat per kilogram than water at the same temperature. What’s the problem with that?

Anastassia:
Thank you for your further explanation, which I found thought-provoking.
You say, “If we let the partition between the boxes move under the action of the higher pressure, we will see an oscillating motion.” I suppose you mean the gas on each side will act as a spring, with the partition as the weight, so we get simple harmonic motion. If we allow the partition to conduct heat, I see that its average position will move to the center. Otherwise, the partition can remain away from the center forever.
You go on to say, “If the heat transfer is efficient, no motion will develop.” For this to be true, the mass of the partition has to be so large that the pressure difference causes only negligible acceleration during the time it takes for the temperature to equalize. I can’t think of any physical material that would meet that requirement. So you must be talking about fixing the partition in place with glue or a few nails.
Now you talk about a pressure difference and how, “In this case there is no way to reach the equilibrium other than to move the partition. ” Well, that’s true. If your partition is impermeable to pressure, the partition must move. But it’s also true that if your partition is impermeable to heat (insulating), the partition will have to move.
You say, “In the second case, there is no way to reach the equilibrium other than by doing work ” I disagree. You could make the partition vanish in an instant, and the two bodies of gas would mix freely without doing any work. We could make the partition out of thin latex and pop it. The mixing would be isenthalpic, but not isentropic. Or we could also put a throttle between the two, and let the gas go through the throttle without pushing anything around.
I agree that heat and work are different, but I don’t think your examples have pointed out the difference. Furthermore, the fact remains that moist air expands more than dry air when the two experience the same pressure drop. Moist air will end up less dense. It will float above any surrounding dry air.

Kevan
For me it is a pleasure to discuss all this, so thank you for your further comments. We are looking for interest, that is why this unusual appeal.
In both cases in the box example we originally nail the partition such that it is, in your words, impermeable for pressure.
The important distinction is that if the partition is permeable for heat, in the first box the equilibrium sets in without generating any motion. In the second case, the disequilibrium will infinitely persists until the partition is allowed to move. If we remove the partition, as you point out, we will also see air motion in the second box.
The use of throttle will equally affect the motion in both boxes. This is just equivalent to introducing resistance for the flow.
This box example illustrates the well-known point that if you want to obtain work from heat, you must be concerned about the efficiency. That is, about the share of extra pressure that will leak as heat without performing any work.
You say

Furthermore, the fact remains that moist air expands more than dry air when the two experience the same pressure drop. Moist air will end up less dense. It will float above any surrounding dry air.

Several dozen comments ago I wrote:

If there is air ascending without condensation nearby starting from the same surface temperature and if all latent heat remains in the volume where condensation takes place (nothing is radiated to space), then the pressure in the column where condensation takes place can be higher — if the surface pressure is the same.

In essence, we do not seem to be in disagreement. However, your general conclusion, about moist air floating above any surrounding dry air, neglects all those ifs and is equivalent to neglecting the efficiency of transformation of heat to work.
Let me also say that while discussing buoyancy is undoubtedly interesting per se, our paper is not about buoyancy and not about the impact of condensation on buoyancy. The condensational pressure gradient force can make the air rise even if it is negatively buoyant in comparison to the surrounding air. By the way, atmospheric updrafts characterised by negative buoyancy are pretty common (see, e.g., Folkins 2006).
wayne
Thank you for your comments. Surface evaporation is implicitly taken into account in the condition dNv/dx = 0. This means that despite air pressure falls along the x axis, the saturated concentration of water vapor is maintained constant over the considered isothermal surface by local evaporation. This is discussed in Section 4.5 “Evaporation and condensation”. We have neglected evaporation from droplets.
Regarding forests and their role, you might be interested in reading this paper. In particular, pay attention to Fig. 2c, which compares precipitation patterns in North America (forested) versus China (deforested) at one and the same latitude.
I am signed to receive comments from this thread, so please, if further questions arise, I will be delighted to discuss them as time permits. When we have new work published, I will certainly put a note here.

It’s amazing Anastassia how different branches of science always tend to cross at some point. You bring in osmosis and my major was physiology and my final paper before graduation long ago was the osmotic transport of c14 tagged glucose across the semi permeable membrane in the intestines of a species of worms (pig gut worms actually, can’t recall the species). So, that last explanation is plain ‘English’ to me!
You must be speaking of what would visually show itself at the rolling tops of clouds, not the bottoms where condensation first appears, in the cumulus case the undefined silky gray bottoms. Of course I had never considered osmosis would have a hand in the replenishment of the water vapor. That is interesting.
Or, I guess some of that effect would occur at any stark edge of a cloud where clear air meets the saturated vapor, that in cumulus case, is the constant rolling at the distinct edges and tops and stratus type at mainly the tops. Is that close or way off?
You could be speaking more at the smaller molecular level and this occurring anytime condensation occurs which leaves that depleted parcel exposed with a osmotic gradient but there I don’t visualize an edge.

Here’s a complexification (note to Anna — that’s a made-up word! Don’t borrow it. 😉 ):
My understanding is that the bulk of precipitation begins its condensation/joining cycle not as “droplets” but as ice crystals (since the air temperature high in rain clouds tends to be well below 0°C), and then melt into raindrops on the way down. Hail, of course, goes through numerous fall-rise cycles into the cold zone to build up.
All of which introduces another layer or two of latent heat exchanges to be factored in.

Anastassia, I didn’t understand at first what you were trying to portray but it’s becoming clear. I had a problem grasping what exactly “atmospheric column where the moist saturated air ascends” statement meant in relation to the osmosis. Outside of that column you must mean air that has less humidity, as in a downdraft around that column. In that context I clearly see the virtual ‘membrane’ and the water vapor in the column would always be moving outward to mix with the less humid surroundings therefore losing a bit of humidity as it rose.
Re-reading your first comment over again, twice, I see you are trying to tell me the same thing I was trying to visualize. You were also describing the ‘rolling’ or ‘sustaining continuous air circulation’ as you put it and I went right by it. I’m not quite used to some of the proper atmospheric physics nomenclature, but I’m starting to get it down. I read the whole section four with no problem but section one, well, in general I understand but I would like to grasp each equation and that’s a bit slower. Thanks so much for opening my eyes to some new aspects. Spent a whole summer last year watching clouds float by but now I’ll never look at them quite the same. I need to read section 2 & 3.

David
January 26, 2011 at 11:15 am

I looked at your web site on land use issues and the effects of deforestation etc and find it intresting and informative. Have you been in communication with Dr Pielke Sr and Jr, http://pielkeclimatesci.wordpress.com/ http://rogerpielkejr.blogspot.com/ and are you familiar with their work on land use issues and climate?

I contacted Professor Pielke Sr. several times starting from October 2008 asking for comments/criticisms regarding our work, both on the role of vegetation in driving the hydrological cycle, on the physical bases of condensation induced dynamics and on social issues associated with difficulties of challenging a consensus in climate science and the associated caveats of the peer-review process.
Regarding science, I received two comments from Prof. Pielke, which are as follows. First, Prof. Pielke does not “see how the effect of the changes partial pressure of water vapor can have a major effect relative to the much larger effect of the release of latent heat and other diabatic effects as they alter the vertical and horizontal pressure gradient”. Second, “if the atmosphere is in (or close to) hydrostatic balance, the mass remains unchanged overhead regardless of the phase the water is in”, such that condensation within the atmospheric column cannot instantaneously reduce local air pressure at the surface.
Prof. Pielke advised that we should submit our considerations to an AGU or AMS journal where they will be peer-reviewed. He also advised that we should consider submitting to physical journals as “the advantage of having physicists review your work is that they are not as likely to have some of the biases you report.” In response to our query whether he would find it possible to make a public comment on our work, Prof. Pielke clarified that he “receive(s) quite a few communications to comment on research, and prefer(s) not to generally do that”.
Posted with permission of Prof. Pielke Sr.

Anastassia, does the system I described above elucidate a mechanism for the forces involved in tornadoes/hurricanes that you state are not accounted for in the current meteorological equations? When I asked “does it just not happen that way” I was not being facetious. I don’t know how the atmospheric dynamics play out. For mass to increase in the volume while maintaining hydrostatic equilibrium, I can imagine the dynamics but they are very tricky.
At condensation the water vapor itself loses vapor pressure, so there is a negative pressure coupled with latent heat. Is that negative pressure likely to pull in air from the same horizontal level? Is the air at that horizontal level likely to be at or near the same dew point at which condensation just occurred? In that case, the negative pressure of condensation can indeed pull in more air that condenses in the same volume, increasing the mass of that atmospheric column.
Coupled with the release of latent heat, you can get a growing mass of water condensate that remains in hydrostatic equilibrium if the energy of it’s own latent heat is increasing the vapor pressure from below and decreasing the vapor pressure from above. There is a large build up of pressure potential with the mass of water acting as a barrier in between. Take the water out of the way and you will experience a sudden large negative pressure at the surface. The atmosphere below is REALLY going to want to push through that cloud. It will eventually either: punch a hole through, spread out horizontally and seep up around the edges, or transfer its heat to the cloud by contact.
If a hole is punched, condensate will fall adjacent to warm, rising air. The condensate can then pick up the energy needed to vaporize again, allowing it to join the rising warm air. Depending on the scale of your suspended cloud layer and the size of the whole punched through it, I can imagine how this dynamic could create either a hurricane or a tornado.

Steve
February 2, 2011 at 5:09 pm
Thank you for your further comments.

(1) There is a large build up of pressure potential [due to decrease of partial pressure of vapor by condensation] (2) with the mass of water acting as a barrier in between. (3) Take the water out of the way and (4) you will experience a sudden large negative pressure at the surface. (5) The atmosphere below is REALLY going to want to push through that cloud.

You ask my view. Statements (1), (4) and (5) are correct. Statements (2) and (3) are not.
The idea that nothing happens until the mass of condensate is removed represents a fundamental physical misunderstanding of the nature of hydrostatic equilibrium. This misunderstanding is spread widely, as illustrated, for example, by the quoted comment of Prof. Pielke above and earlier of Dr. Gavin Schmidt. The error is visualized with utmost transparency in the work of Bryan and Fritsch (2002) (see our critique here, p. C12011), where a static (motionless) atmosphere in equilibrium accomodates liquid droplets that neglect gravity by hanging around everywhere throughout the atmospheric column, while the air pressure is strongly non-hydrostatic (due to the rapid decline of vapor pressure with height).
The correct equation for hydrostatic equilibrium is
   (1)
where is total air pressure (vapor plus dry air), is total air density.
This fundamental equation is replaced in meteorology by the following one:
,    (2)
where is the total amount of matter, including liquid, per unit volume. From this equation one concludes that surface pressure remains unchanged until the total mass of the column changes.
For pressure at an arbitrary height we have from (2)
    (3)
Now let us see how (2) violates the ideal gas law. Suppose initially we had a static equilibrium atmosphere with no liquid, . It satisfies both (1) and (2). Then we took an air volume at some height and replaced it with an air volume with the same total density but containing liquid instead of vapor. That is to say, we first had and then , with and kept constant.
Since neither the total amount of matter in the column nor total density distribution has been changed by such a procedure, from the modified “hydrostatic equilibrium” (2) and Eq. (3) we would have to conclude that pressure has not changed either. Dr. Gavin Schmidt referred to this as “condensation *per se* has no effect on air pressure”.
But the ideal gas law teaches us that pressure (which is, by the way, a scalar) is proportional to the total number of particles per unit volume. By replacing vapor by liquid we have reduced the amount of particles by the number equal to the number of vapor molecules. In the result, pressure at has dropped by the amount of partial pressure of vapor: .
To summarize: liquid does not make a contribution to the ideal gas pressure, in contrast to what Eq. (2) supposes.
Immediately upon replacement of vapor by liquid, pressure has dropped and a non-equilibrium pressure gradient force appeared. By formulation, this force will be (and have been) ignored in all models where hydrostatic equilibrium is incorrectly represented by Eq. (2).
The deviation of the observed pressure distribution from (1) can tell us how much liquid falling at terminal velocity the upwelling flow could possibly sustain in the atmosphere. (Direct observations show, btw, that this amount is very minor, . ) But it is not the other way round! The amount of liquid that suddenly appears in the atmospheric column has nothing to say about whether the hydrostatic equilibrium is maintained or not.

wayne
February 2, 2011 at 8:02 pm

Don’t leave density out of your considerations. Pressure is only on side of it. Both play into the dance in the sky so to speak.

Thank you for your further comments. One of our points is that the Archimedes force associated with buoyancy is minor in comparison with the condensational pressure gradient force associated with vapor removal from the gas phase.
Kevan provided several useful calculations which can be viewed as epitomising the concerns of Prof. Pielke and some other scientists about the “much larger effects of latent heat.” Let me overview them here once again.
The release of latent heat diminishes the rate at which temperature drops with height when the air ascends adiabatically. The moist adiabatic lapse rate depends on the amount of vapor and grows as the vapor is depleted: from about 4 K/km at the surface at T = 20 C. The dry adiabatic lapse rate is 9.8 K/km (you can see these lapse rate profiles in Fig. 2e here). At 10 km the cumulative temperature difference between the moist adiabatic and dry adiabatic columns amounts to about 30 K, or 10% of absolute temperature T ~ 300 K.
At one and the same pressure the air that is warmer by 10% will have approx. 10% lower density rho’ = pM/R(1.1T) than air at temperature T with rho = pM/RT . This estimates the net effect of buoyancy as (rho’ – rho)g as 0.1 rho g. This gives us 1 N/m^3 if we take rho = 1 kg/m^3 (in reality rho is lower at 10 km, but we neglect this). Kevan correctly estimated (see also my reply) that even complete removal of vapor by 10 km will make a minor correction to this estimate. (To which direction — depends on how you define the atmospheric columns that you are comparing. One can argue that removal of vapor with Mv = 18 g/mol makes the air heavier (reduces buoyancy) by increasing its molar mass M ~ 29 g/mol. Alternatively, one could conclude (as Kevan originally did, if I got him right) that vapor removal increases buoyancy by decreasing pressure p. But in either case the effect is minor due to the small ratio pv/p ~ 0.01.)
It is at this point where some people would stop having concluded that the condensational vapor sink is unimportant for atmospheric dynamics.
In our paper we are presenting a different force, not calculating a contribution of the vapor sink to buoyancy. This condensational pressure gradient force is estimated as dpv/dz = pv/hv ~ 1 N/m^3 in the lower atmosphere (pv ~ 2×10^3 Pa, hv = 2 km). As one can see, thus estimated, the two forces — buoyancy and condensational — are of comparable magnitude, 1 N/m^3. (This is another interpretation of the result shown in Fig. 1c of our paper, where the maximum pressure differences above and below zc are approximately the same).
But the buoyancy effect estimate is a gross overestimate. In reality 30 K temperature differences are practically never observed between the areas of ascent and descent. Horizontal mixing destroys this theoretical temperature difference, making the lapse rate close to the average value of 6.5 K/km everywhere. Moreover, the dry adiabatic descent increases surface temperature in the region of descent, further diminishing the theoretically possible temperature and density difference. There is also the problem of surface to volume ratio (a small warm balloon and a several hundred or thousand kilometers’ wide warm atmospheric volume will differently react to buoyancy differences).
In our paper we do not estimate the buoyancy effects (enormous work has been done on that). We show that the condensational pressure gradient force alone is sufficient to explain the observed circulation intensity on a variety of spatial scales. This is an independent argument that, in the same context, the buoyancy effects (whether due to latent heat release or differential heating) are minor in comparison. The continued neglect of the condensational pressure gradient force is scientifically unjustified.
Note that both the buoyancy-related (rho’-rho)g and the condensational pressure gradient pv/hv forces are vertical forces. Under the independent condition that the atmosphere is close to hydrostatic equilibrium, the action of both forces is manifested via formation of horizontal pressure gradients, like the one we estimate in Eq. 37 of our paper.
Note also the different spatial localization of the forces: as calculated above, the buoyancy related force depends on height and grows with increasing temperature difference caused by latent heat release. The condensational pressure gradient force, in contrast, dominates in the lower several kilometers of the atmosphere, i.e. where most weather phenomena that affect our life occur. The condensational pressure gradient force tends to zero in the upper drier atmosphere due to the decrease of pv.

Anastassia,
I can’t tell you how much I have enjoyed this conversation. You have really open my eyes to some very important aspects of water vapor. So I don’t overstay the welcome I’ll just add a few things that might let you know where I was coming from and a pointer that might make it easier for you to press your point while trying to get others to see deeply into your paper, but quickly.
I almost feel a bit of boyish guilty of hijacking this topic and dragging it into talking of single clouds while all of the time I did realize that your paper is speaking on a much, much larger scale, cloud/vapor systems at the global scale. Here’s why: I spent so many hours years ago in a sailplane trying to understand clouds. I was failing miserably. The manuals told of heat, thermals, condensation and what on the ground you were to look for to lead you to these invisible thermals. Of course it is heat, look for dark plowed fields below, large black parking lots, etc that is where you will find lift. It also pointed out to stay away from water, forests, and most anything green for that was always where the sink would be for these were always cooler.
Well, as it turned out that simple explanation in the manual was wrong about half of the time. A large lake with green around the edge usually, if there was a slight breeze, would have great thermals with clouds always on the leeward side and that made absolutely no since at the time. Here was two cool surfaces with great lift and the dry, dark plowed fields closer to the airport had terrible sink, we were then in a drought and it was bone dry. I was lost, moisture never crossed my mind. To the library for meteorology books. They said basically the same, it’s all in the heat.
I guess you see my absolute glee in your paper. You have answered a question I have pondered on for some twenty five years. I kick myself now, of course, it’s the condensation, dummy! See, I was trusting the authorities, the manual and meteorological books as the information source without ever questioning it. What enlightenment. Even though that sailplane experience only lasted for a few years and that was long ago I think I’ll pass this information on to some soaring clubs and maybe Schweizer sailplane manufacture to have them pass it along to any newbies. Every pilot when soaring should know this effect.
So much for that.
Now, on your paper, it was a tiny mention of someone above that mentioned that water vapor takes up 1000 times more volume that water. That is all it took to get my attention !! Otherwise, I might have skipped right by this whole post. Meteorology always interests me but seeing deep math sometimes I think, don’t have time right now and go on, super glad I didn’t.
I calculated that 1000x volume and came up with a much larger value, I hope I did it correct, some 23500 times the volume, water to water vapor. Really either if these values are big enough to work in letting anyone visualize immediately this huge differences involved, for without that mental view, it seems many just pass it something like this: it’s a big atmosphere so surely some water vapor is not going to make that much difference. Next time it rains 4 inches over this state I will know it is equal to some one and a half vertical miles of the atmosphere that just fell. Anyone with the least bit of imagination knows immediately that this results in huge horizontal pressure differences.
I wish all science papers were required to have a “plain English” lead in so a mental view could be formed before the heavy math came into play, but that’s just the way my mind works. Guess I’m suggesting that you might consider getting it visual up front. Sometimes pure equations can hide the huge scale until you get your mind deep into them and start applying some actual numbers. Just a thought.
Wish I could be more help but my sidetrack into planetary atmosphere physics (climate science ☺) started but a little over a year ago. My last thirty years of interest in physics has always been more in other areas, particle physics, astrophysics, gravity, etc.