Makarieva et al: Condensation driven winds – an update

Posted: January 31, 2013 by Rog Tallbloke in solar system dynamics

tallbloke:

Important post

Originally posted on Climate Etc.:

by Anastassia Makarieva, Victor Gorshkov, Douglas Sheil, Antonio Nobre, Larry Li

It’s official: our controversial paper has been published. After a burst of intense attention (some of you may remember discussions at Climate Etc., the Air Vent and the Blackboard), followed by nearly two years of waiting, our paper describing a new mechanism driving atmospheric motion has been published in Atmospheric Chemistry and Physics.

View original 2,725 more words

Comments
  1. tallbloke says:

    This is great. New science to fathom.

  2. Stephen Wilde says:

    Although I was negative in some of my earlier comments that was primarily a result of being distracted by the biotic pump material.which seemed somewhat political in character.

    I agree with the basic premise that condensation does involve an effect on atmospheric pressure but that is simply a mirror image of the effect of evaporation lower down.

    The question seems to be whether there really is something new in this that is not already implicit in the known workings of the water cycle and adiabatic ascent and descent within the main high and low pressure cells that together form our permanent climate zones.

    It is clear that the water cycle enhances the adiabatic movements within an atmosphere and perhaps this is the first attempt to quantify and explain that enhancment in detail.

    Certainly potential energy is at the heart of the matter and latent heat is indeed a form of potential energy so this could well be consistent with my own ideas regarding the water cycle as a regulating factor.

    Whether it is a complete answer to the question as to how the atmosphere might stay at the same temperature despite variable radiative characteristics of constituent gases may be doubtful (I think it is primarily a pressure based process involving adjustments in atmospheric volume) but it may well be a useful step forward in explaining how the parts of the system fit together.

  3. tallbloke says:

    Stephen: “I think it is primarily a pressure based process involving adjustments in atmospheric volume”

    Yes, This is the issue. And the authors say condensation of water does plenty of adjusting of volume. Which adjusts pressure.

  4. Stephen Wilde says:

    And volume ?

    I’d say evaporation expands the air at low levels whereas condensation contracts the air at higher levels which is a pressure pumping process as they say.

    But that relates only to the troposphere and there is a lot going on above the tropopause which has an equally important role in stabilising the system even though more than 90% of atmospheric density is below the tropopause.

    I would say that the water cycle acting via surface pressure on and sunlight into the oceans does most of the work below the tropopause but higher up the main effects are solar influences on atmospheric composition especially involving ozone.

    The Makarieva paper has a place but it is not sufficient in itself.

    Forests clearly have an influence too but I’m sure that the ITCZ ( above the tropical forests) and the mid latitude depression tracks (above the mid latitude forest belts) were in place before the forests grew so the implication is that wetness causes forests rather than vice versa.

    I’ll be very interested to watch how it goes at Climate etc and elsewhere.

  5. tallbloke says:

    Stephen: “higher up the main effects are solar influences on atmospheric composition especially involving ozone.”

    In the stratoosphere yes. But not far below, Solar influences on specific humidity at the 300mb level are going to affect things too.

  6. dlb says:

    Stephen Wilde,

    I used to be quite sceptical the role transpiration plays in troposheric climate. But the graphs at the website “climate4you” have convinced me otherwise. It would appear the Nth hemisphere forests increase global column water vapour by around 15% each year, peaking in August – September.

    I would have originally thought the oceanic dominant Sth hemisphere would have caused a peak around March, which is not the case.

  7. Stephen Wilde says:

    tallbloke and dlb.

    Points taken but tallbloke is referring to long term specific humidity whereas dlb is referring to seasonal relative humidity.

    I agree that both affect things as part of the overall thermal stabilisation mechanism but they are peripheral to the main point raised by Anastassia and her colleagues.

    Apart from that I think I have worked out why talk of ‘pressure’ has become confusing.

    For a planet with a fixed atmospheric mass and a fixed gravitational field there can be no absolute change in total pressure.

    All that can happen is that from place to place there can be pressure variations in the horizontal plane relative to the vertical plane.

    Thus, considering a single parcel of air of indeterminate initial volume:

    i) That parcel of air can be caused to expand relative to adjoining air parcels either by direct input of more solar energy where insolation is uneven (as it always is) or indirectly by the injection of potential energy in the form of latent heat of evaporation carried by water vapour.

    Once it expands it pushes against the adjoining parcels so pressure increases in the horizontal plane but pressure in the vertical plane remains the same so the expanded and lighter air parcel moves in the direction of least resistance which is upward.

    In the vertical plane viewed from the surface one then has lower pressure because the rising air is less dense and lighter. The higher the column of rising less dense air goes or the faster it rises the lower surface pressure will become in the vertical plane.

    At the same time the changed pressure relationship between the vertical and horizontal planes will set up an air flow which serves to bring in new air low down to replace at the surface the air that has risen.

    In extreme scenarios there can be tornados or hurricanes.

    Note that from a meteorological point of view that is the formation of a low pressure cell because pressure in the vertical plane has dropped in order to relieve the increased pressure in the horizontal plane.

    ii) Now let’s look at the other side of the same scenario which is the condensation process that Anastassia is considering.

    When condensation occurs that parcel of air shrinks relative to adjoining parcels when it loses its latent heat of evaporation via condensation.

    Having shrunk it no longer pushes against adjoining air parcels. Instead it gives way and pressure in the horizontal plane falls. Again, pressure in the vertical plane stays the same so the contracted and heavier air parcel moves in the direction of least resistance which is downward.

    In the vertical plane viewed from the surface one then has higher pressure because the falling air is more dense and heavier. The higher the column of descending less dense air or the faster it descends the higher pressure will become in the vertical plane.

    An air flow will be set up whereby the descending air replaces the air at the surface that has gone to replenish the nearby rising column and there we have a circulation.

    So, in light of that it is potentially misleading to say that condensation causes a reduction in pressure because one assumes that such reduction in pressure has occurred in the vertical plane so as to accelerate convection.

    In fact, condensation only results in a pressure reduction in the horizontal plane and the only effect of that lateral pressure change is to complete the downward half of the circulation already provoked by the initial uplift.

    Note that I said that the initial uplift could be caused by any provision of more energy at the surface.

    That means that the process I have just described is applicable with or without a water cycle. The only effect of a water cycle is to increase the sensitivity of the system as a negative response to surface heating.

    The water cycle assists stabilisation of top of atmosphere energy balance and reduces the need for a more vigorous circulation.

    The effect of CO2 and other non condensing GHGs is just the same but without the added efficiency provided by phase changes.

    All GHGs make it easier and not harder for the global circulation to match energy in with energy out at top of atmosphere.

  8. Derek says:

    Condensation does have a large effect. It is a fact that the tropopause lowers considerably above convection cells (this has been observed over areas, for seasons, not just individual thunderstorm cells…). Presumably due to the reduced pressure caused by….. condensation of water vapour.. Which releases heat and increases IR emissions that can more easily escape to space, because the tropopause has owered as a consequence of ….condensation of water vapour…. Latent heat of water vapouriastion and condensation is a massive, constantly variable, AND with a far greater capacity than it needs or usually uses, to pump of energy from earth’s surface to space, in a very similar manner to how a fridge works. Literally earth’s surface is a solar and geothermal powered refrigerator. The refrigerant is water by it’s phase changes from liquid to gas and back again to liquid. Anastassia Makarieva, Victor Gorshkov, Douglas Sheil, Antonio Nobre, Larry Li are on the right track.

    If some lose the GH obsession (there is no such thing – it is IMAGINARY), and the radiative obsession (importance WITHIN earth’s climate system GROSSLY over estimated due to incorrectly accepting the black body power = amount assumption), we will all get a lot further, a lot quicker.

  9. Stephen Wilde says:

    “Condensation does have a large effect. It is a fact that the tropopause lowers considerably above convection cells (this has been observed over areas, for seasons, not just individual thunderstorm cells…). ”

    Yes that is part of my point.

    Condensation high up lowers the heights (higher surface pressure) whereas evaporation lower down raises them (lower surface pressure).

    Reading the reference to reduced pressure from condensation in Anastassia’s paper one gets the impression that she and her colleagues think that the upward force is enhanced by condensation but it is not.

    On the basis of my detailed description above the reality is that evaporation causes lower surface pressure by pushing aside adjoining parcels of air in favour of a lighter less dense parcel of rising air and condensation causes higher surface pressure by allowing adjoining parcels of air to flow back into the vacated space once more so that it is occupied by heavier more dense descending air.

    I suspect that if the air that has had its vapour removed were visible then we would see it being pushed aside by the rising column and cascading down the outside of the growing turrets of cumuliform clouds as they continue to press on upward.

  10. tallbloke says:

    I’m going to concentrate on trying to understand Makarieva et al’s update rather than do battle with Stephen’s restatement of his own hypothesis.

  11. Stephen Wilde says:

    Fair enough Rog, but rather than a restatement it is a linking of my hypothesis to her correct observation that pressure reduces locally when condensation occurs.

    It might reduce horizontally but the inflow of less vapour rich air actually raises surface pressure.

    Above the air parcel involved there is no reduction in pressure because the weight of the molecules above the air parcel stays the same for any given height. A reduction in pressure can only occur laterally.

    You can’t reduce surface pressure as a result of evaporation and reduce surface pressure again when condensation occurs.

    That would be a rather neat perpetual motion machine.

  12. tallbloke says:

    Pressure is reduced when precipitation occurs however. Water is heavy stuff.

  13. Stephen Wilde says:

    Rising air from surface heating leads to a surface pressure reduction then to condensation higher up and then often but not always precipitation follows.

    Precipitation doesn’t cause a reduction in pressure at the surface but I do accept that condensation causes a reduction of pressure in the horizontal plane leading to an inflow of air that is denser than the vapour laden air was for a net recovery of surface pressure.

    Vapour laden air is clearly less dense and lighter than vapour free air.

    Since rainfall is just an agglomeration of droplets that have already condensed out there is no further pressure reduction from that agglomeration.

  14. tallbloke says:

    “This relationship determines that in hydrostatic equilibrium any work -w∂pi/∂z performed by the vertical partial pressure gradient per unit time per unit atmospheric volume is compensated exactly by the work -wγiρg performed by the force of gravity that acts on a corresponding molar share γi of the air mass (here w is vertical velocity). In other words, all work performed by the non-condensable gases as they ascend and expand is fully spent on elevating their respective molar shares of total air mass in the gravitational field. Nothing is left to generate kinetic energy.”

    Leaving aside the dangerous wording which states that the force of gravity does work, is there an implicit recognition in here that the lapse rate pre-exists the dynamic motion of the atmosphere? That would please Hans Jelbring. Could it be that through their quantification from first principles, Makarieva et al have found empirical proof of the Loschmidt conjecture? :)

    I think to avoid problems they would be well advised to restate this in terms of potential and kinetic energy. Stephen might then find it easier to integrate their theory with his own hypothesis too.

  15. Derek says:

    Err,
    “pressure reduces locally when condensation occurs”
    Yes.
    “Condensation high up lowers the heights (higher surface pressure)”
    I can not see this. Tropopause lowers for starters. Is it a too simplistic pressure at earth’s surface is the weight of all the air above you view point?

    Loschmidt, Jelbring, and Cotton take little, to no account of, change of state (gas to liquid specifically) to my understanding. Anastassia Makarieva et al do. BIG DIFFERENCE.

  16. tallbloke says:

    Derek: Sure, Makarieva make a far more detailed study of the internal dynamics of an active atmosphere with energy passing through it. What interests me is their statement that gravity is doing work. If it is, when will it all be used up? I ask because I want to know when I’ll be needing to fasten my clip harness to something solid. ;)

    What I’m getting at is that Makarieva et al seem to be working with -g/Cp for the lapse rate, as an independent axiomatic state of affairs before they deal with parcels of moist air moving around in it. That would imply a non-isothermal equilibrium. I may be wrong of course, but I’d sure like one of the author team to explicitly tell me.

  17. Derek says:

    “What I’m getting at is that Makarieva et al seem to be working with -g/Cp for the lapse rate, as an independent axiomatic state of affairs before they deal with parcels of moist air moving around in it. That would imply a non-isothermal equilibrium.”

    Penny drops, I think you are correct in that is what they appear to be saying. The quandry being that the non-isothermal equilibrium (with altitude) will show up on a solid thermoeter as a temperature drop due to reduced gas pressure.

    Such a pity “we” can not measure the individual gas molecules total kinetic energy, nor it’s constituent parts. This could run and run…

  18. tallbloke says:

    “This could run and run”

    I’m sure it will. Especially after I present new experimental evidence for a thermal gradient in a column of air in a gravitational field which I have been sent. :)

    But I want Marakarieva et all to clarify the issue first, and have emailed her and Douglas.

    “a pity “we” can not measure the individual gas molecules total kinetic energy”

    I think this may lie at the root of Nick Stokes objection:
    http://judithcurry.com/2013/01/31/condensation-driven-winds-an-update-new-version/#comment-290718
    But your justification was based on molecular kinetics, and you incorporated it in a continuum equation. Now you seem to be saying that, if that’s wrong, it’s still true on some larger averaged scale. But what is the justification for that? And how can an averaged result be incorporated in differential equation maths?

  19. tallbloke says:

    Berényi Péter says:
    http://judithcurry.com/2013/01/31/condensation-driven-winds-an-update-new-version/#comment-290686
    “We have described a new and significant source of potential energy governing atmospheric motion. Previously, the only such recognised energy source was the buoyancy associated with temperature gradients.”

    OMG. Is this piece of 19th century physics new in this field? Gravity is a weak force, molecular forces are strong.

    Moving water into the gas phase, 1 micron away from the surface of droplets (evaporation) needs the same amount of work required to lift it to a height of 230 km above Earth’s surface. In case of ice crystals (sublimation) it is 264 km. These values are more than an order of magnitude higher, than tropospheric thickness, therefore potential energy storage in the atmosphere is dominated by the water cycle.

    Also, mass of water evaporated (and recondensed) annually is roughly the same as that of the entire atmosphere. Most of it (~90%) never reaches the surface, but re-evaporates in mid air. Atmospheric distribution of water is extremely non-uniform on all scales.

    Back-of-the-envelope calculations do have their merit.

  20. tallbloke says:

    Given Peter’s comment, it may be that the origin of the lapse rate isn’t too much of a hill of beans so far as Makarieva et al are concerned.

  21. Stephen Wilde says:

    “Is it a too simplistic pressure at earth’s surface is the weight of all the air above your view point? ”

    That would be the correct approach.

    The pressure differences observed at the surface would then depend on the density of the air in the column immediately above the observing position.

    Generally, warmer or water vapour laden air is less dense and lighter so a lower pressure is observed.

    Colder air or air with no water vapour is more dense and heavier so a higher pressure is observed.

    When condensation has occurred there is more colder denser air able to enter the column from the sides because of the shrinkage of the formerly vapour laden air so pressure gets higher as measured from the surface.

    The amount of air above the parcel of air remains the same so no change in pressure above the air parcel occurs.

    I’m intrigued by tallblokes suggestion that raining out of the condensed water vapour involves lower pressure. I would have thought that once the water has been removed by precipitation then the drier air would be heavier and so would have a higher pressure.

    We do see pressure falling before rain (increasing water vapour) and rising after rain (decreasing water vapour).

    Water vapour is lighter than air which is why humid air is lighter (lower pressure) at a given temperature but water droplets are much heavier than air so I see tallblokes point but it doesn’t seem to work out the way he suggests because heavy droplets rain out so as to be no longer available to affect the pressure of the column and any droplets that do not rain out have already affected pressure at the point of condensation and so will have no additional effect when they clump together prior to falling.

  22. Derek Alker says:

    Stephen, given the diurnal bulge, how can one say that the pressure at earth’s surface is the (sum) weight of the colum of air above that point? If that were the case gases would not be buoyant, and how would one explain the diurnal bulge?

    It is perfectly possible to have two parcels of air at the same temperature and the same pressure, BUT with differing amounts of moisture in them. The moister air parcel would be lighter and hence convect, because convection is gravity powered. I wonder if the suggestion that moister air will be of a lower pressure is in effect from a retrospective view point, when the air itself has no memory of what it was.

    Tallbloke, thanks for pointing out that I agree with Nick Stokes….GULP. LOL, that is rare… But, it is a concern I have also been raising. I have been told I only need to consider total KE, and then immediately I am given an explanation that then goes on about rotational energy, translational energy, etc, etc, etc. In other words that is not the only issue that “Loschmidt” wants to take whichever way suits, when it suits, or so it seems to me. Of course, it could be me just not understanding what has tried to be explained to me.

    I am very interested in the new evidence you mention.

    I like part of Stephen’s approach, and I like part of Makarieva et al approach, but niether in total.

    “Loschmidt” I just can not see. A rubber ball has PE, but a buoyant gas!!!! No, at least, not in the same way. I keep getting the feeling this is a solid or liquid explanation applied to a gas. Which might explain the apparent flip flopping mentioned above.

    BTW – When a buoyant gas (with in effect little or no PE) condenses and becomes a liquid, all of a sudden it has PE. That I would describe as a gravity energy input. It is constantly available, but that does not mean it is a constant input.

    I am still trying to understand Peter’s comment, but it sort of sounds right.

    [Reply] Sorry for delay, dropped into spam bucket for unknown reason.

  23. DocMartyn says:

    This is worth a read and needs to be digested by someone with more physics than me

    http://weather.ou.edu/~tanamach/IRPaper.PDF

    Infrared Thermal Imagery of Cloud Base in Tornadic Supercells

    Might I also suggest someone has a look at

    Infrared characteristic radiation of water condensation and freezing in connection with atmospheric phenomena; Part 3: Experimental data

    Tatartchenko, V.; Liu, Yifan; Chen, Wenyuan; Smirnov, P.

    Earth Science Reviews, Volume 114, Issue 3, p. 218-223.

  24. Stephen Wilde says:

    tallbloke:

    i) Pre condensation a given volume contains:

    a) Water vapour and b) A quantity of air.

    ii) After condensation that same given volume contains:

    a) The same amount of water vapour in condensed form and b) That initial quantity of air and c) More air and water vapour imported from the surroundings.

    Isn’t ii) going to be heavier than i) for a net increase in surface pressure ??

    What has happened is that a nominal pressure reduction locally at height caused by contraction has imported more molar material into the original volume for an increase in pressure at the surface below.

    Isn’t tthat a serious problem for Anastassia ?

    Derek:

    I don’t think the diurnal bulge is relevant.

    That is caused by expansion from solar heating which comes and goes between day and night causing expansion and contraction of an entire half of the atmosphere at a time.That is quite different from condensation contracting volume locally such that more molar material can be imported to that inital volume from the surroundings in the way I just explained to tallbloke.

    Although the height of the atmosphere varies from day to night the amount of molar material in the vertical column remains the same at any given location.

    That is also why one cannot change average surface pressure for an entire planet from a rising or falling of the atmosphere as a whole.

    In contrast, the process of condensation results in a lateral redistribution of molar material which does alter the weight of the vertical column from one place to another.

    Likewise, evaporation pushes the adjoining denser air away thus reducimg the amount of molar material in the expanded parcel containing water vapour.

  25. tallbloke says:

    Stephen: “What has happened is that a nominal pressure reduction locally at height caused by contraction has imported more molar material into the original volume for an increase in pressure at the surface below. Isn’t that a serious problem for Anastassia ?”

    Well, it has also ‘stretched’ the surrounding air, lowering its density, so it depends on the scale you are considering. If it does suppress convection from below, then that argues for the more likely lateral filling of the reduced volume of the parcel where condensation takes place. That supports her argument rather than causing it a serious problem I would have thought.

  26. Stephen Wilde says:

    The surrounding air is the rest of the globe so I don’t think any stretching of it will count for much compared to the injection of additional molar material into the original (not the reduced) volume.

    ii) above clearly contains more material than i) above so it must have a greater weight and thus a higher surface pressure.

    Evaporation creates buoyancy and condensation removes it.

  27. tallbloke says:

    Stephen:”Evaporation creates buoyancy and condensation removes it.”

    Until the precipitate goes into freefall.

    Returning to the science under consideration in this thread and contnuing from the quote I posted above:

    By contrast, if we consider the saturated water vapor, condensation means that we have

    (eq 2)

    That is, the work of the partial pressure gradient of water vapor greatly exceeds what is needed to overcome gravity. The main physical statement behind our new view is that this net remaining power q (W m−3)

    (eq 3)

    is available to generate kinetic energy and drive the Earth’s atmospheric dynamics. Roughly speaking it is the power that remains after the water vapor has “lifted itself”. The value of q represents the volume-specific power of the “motor” that drives the atmospheric circulation.

    The formation of strong vertical winds is directly inhibited by the atmosphere’s condition of hydrostatic equilibrium. For that reason the dynamic power of condensation is mostly translated into the power of horizontal pressure gradients and winds:

  28. Stephen Wilde says:

    “Until the precipitate goes into freefall.”

    How does that change surface pressure and for how long ?

    I liken the effect of falling precipitation to that of a downdraft from a cloud. Obviously it affects surface pressure on a short micro basis but has little effect on the pressure trace shown by a barograph which gives falling pressure as humidity rises and rising pressure as humidity falls with no discernible variation from falling precipitation.

    I’m pretty sure that Anastassia is discussing macro rather than micro so we can consider vapour and condensate alone with precipitation being pretty much ignored because the pressure change occurs at the moment of condensation from vapour and not at the time precipitation arises from clumped together particles of condensate or at the time precipitation hits the ground.

    Is there any authority for precipitation in free fall making a difference to surface pressure ?

  29. tallbloke says:

    “Is there any authority for precipitation in free fall making a difference to surface pressure ?”

    Only needs logic. If the weight of the water is no longer being carried by the air parcel, the air parcel becomes more buoyant, reducing pressure below.

  30. Stephen Wilde says:

    I accept the logic but is that a good guide to significance ?

    Pressure rises after rain and the removal of humidity because air is heavier than water vapour.

    The function of precipitation in removing humidity seems to have a larger effect on pressure than the weight of the condensate itself.

    It is a dynamic system after all. Precipitation is just a transitional phase in the reduction of humidity and that reduction results in a pressure rise.

    That isn’t Anastassia’s point though.

    She says that the contraction that occurs when condensation happens reduces pressure but in fact although it reduces local pressure momentarily the contraction actually increases surface pressure by pulling more molar mass into the original volume.

    ii) above is clearly heavier than I) above.

  31. Derek Alker says:

    Tallbloke – No problem re earlier delayed reply. It might be because I post from two different computers, depending on where I am. I have lost many posts before on other blogs in a similar manner, so maybe it is a blog software thing.

    btw – http://www.globalwarmingskeptics.info/thread-2095-post-12271.html#pid12271

    DocMartyn says:
    February 2, 2013 at 2:51 am

    This is worth a read and needs to be digested by someone with more physics than me

    http://weather.ou.edu/~tanamach/IRPaper.PDF

    Infrared Thermal Imagery of Cloud Base in Tornadic Supercells

    Might I also suggest someone has a look at

    Infrared characteristic radiation of water condensation and freezing in connection with atmospheric phenomena; Part 3: Experimental data

    Tatartchenko, V.; Liu, Yifan; Chen, Wenyuan; Smirnov, P.

    Earth Science Reviews, Volume 114, Issue 3, p. 218-223.

    These sound very interesting, and very relevant. I hope I can find the second one in partcular. Does anyone have a link for it please?

  32. tallbloke says:

    “although it reduces local pressure momentarily the contraction actually increases surface pressure by pulling more molar mass into the original volume.”

    Molar mass isn’t created ex nihilo, if there’s more of it in the original volume, it’s because there’s less of it in adjacent volumes. I think to get to the bottom of what happens to surface pressure, we’d better include all the other factors (including downdrafted air and the evaporation it promotes as the winds generated blow over the surface, and the increase in columnar height as clouds bubble upwards) and follow the physics M10 and the update expounds, compared to the standard theory.

  33. Stephen Wilde says:

    “Molar mass isn’t created ex nihilo, if there’s more of it in the original volume, it’s because there’s less of it in adjacent volumes.”

    The molar mass in the original volume was initially reduced below global average by the injection of latent heat when evaporation occurred at the surface.

    Condensation simply restores it to the global average.

    No creation ex nihilo.

    Just a simple balanced two way process but it is the evaporation that comes first whereas Anastassia seems to think that condensation comes first.

    You must agree that evaporation is the driver because we have previously agreed that global equilibrium temperature is set by surface air pressure on the oceans controlling the amount of evaporation and the energy cost of that evaporation at a given level of solar input.

    [Reply] “Anastassia seems to think that condensation comes first.” Please, no more of this sort of comment.
    “we have previously agreed that global equilibrium temperature is set by surface air pressure on the oceans controlling the amount of evaporation”
    I hope we’ll be able to engage the authors with our own theory once we have demonstrated that we have made the effort to understand Theirs.

  34. Stephen Wilde says:

    “For that reason the dynamic power of condensation is mostly translated into the power of horizontal pressure gradients and winds”

    Why not say that it is the dynamic power of evaporation injecting potential energy in the form of latent heat into parcels of air that then rise until that potential energy can be released by condensation so as to create a circulation translating into the power of horizontal pressure gradients and winds.

    I think that is what she actually means.

    In that formulation her proposition becomes mundane to anyone who knows about the water cycle but it is true that the climate models disregard it or rather they assume it to be a net neutral phenomenon that is subsumed into radiative theory.

    The essential point that the models omit is the potential for variability within the water cycle so that it can act as a thermostat.

    As least Anastassia’s ideas recognise variability via vegetation changes but in the end the system can negate that too in my opinion.

    Our theory proposes that in the wider pressure based scenario the forest effects on the water cycle don’t matter for eventual top of atmosphere radiative balance but would she accept that?

    Her theory is still valid for conservation purposes but doesn’t then have the all encompassing power that she seems to be claiming.

  35. wayne says:

    “Why not say that it is the dynamic power of evaporation injecting potential energy in the form of latent heat into parcels of air that then rise until that potential energy can be released by condensation so as to create a circulation translating into the power of horizontal pressure gradients and winds.

    I think that is what she actually means.”

    I’ll agree with that Stephen.

    While we are speaking on a more macro-global-scale you also need to look into what gradients, divergence, and curling (back to the calculus of the matter) have to do with this topic, not only laterally as you see on weather isobar maps but vertically as moist air rushes into a low system along the surface and converges and curls upward. The opposite occurring in a high pressure system, divergence in play there.

    Lows are where the air moves generally upward pulling even more moist air near the surface, if available, and the highs are where there is general slow sink maintaining the overall mass balance. Within high systems, with air moving downward, the air diverges and curls horizontally that creates and maintains the force that increases the surface pressure there. Moist horizontal winds blowing into low system have to converge and curl upward creating and maintaining the local low pressure there at the surface even though those both of those air systems may be moving across the surface.

    Maybe take a look at the weather maps in this light. Seems their is a bit of Bernoulli at work at this scale, both horizontally and vertically.

    I’m just not sure Makarieva Etal’s concept has an overriding effect in this global picture though it is bound to have some effect, and the loss of mass definitely needs to be included in the GCMs if not already there.