EHD Model of Tornadoes

[CharlesChandler]

The defining characteristic of a tornadic vortex is that the tightest radius is on the ground. From there, the radius expands in the direction of the flow. The constriction of the radius at the ground is caused by an extreme low pressure that supplies the necessary centripetal force. Above the ground, the low pressure relaxes in the direction of the flow, eventually faring into the lesser pressure deficit within the parent thunderstorm, and the radius expands with the loss of centripetal force approaching the source of the low pressure. (See Figure 1.)

Tornado in Mulvane, KS, 2004-06-12
Figure 1. Tornado in Mulvane, KS, 2004-06-12, credit Eric Nguyen, courtesy Corbis Corporation.

The tight radius at the ground is not just how we distinguish tornadoes from other types of vortexes. The concentration of energy at the ground is what makes tornadoes so destructive. In spite of skin friction, air moving along the ground in response to the extreme low pressure achieves its greatest speeds entering the vortex, and the revolution rate as well as the angular velocity relax with altitude. If the tightest radius and fastest air speeds were at the source of the low pressure inside the cloud, damage on the ground would be far less. So understanding the destructive power of a tornado necessitates identifying the force that constricts the radius at the ground.

In rough terms, a tornado can be considered a vacuum vortex, with a flow field motivated by the low pressure in the cloud above. But the extreme low pressure at the ground, away from the source of the low pressure in the cloud, is unexpected in an open thermodynamic system. If energy can neither be created nor destroyed, and if entropy always increases with distance from the source of the energy, the lowest pressure in any open-air vacuum vortex must always be at the source of the low pressure, which would be inside the cloud. There shouldn't be a way of getting an extreme low pressure away from the source of the low pressure, nor should air speeds be the fastest where the friction is the greatest (i.e., on the ground). Hence fluid dynamic principles do not allow the inverted funnel shape in a open system. Therefore, a tornado is some sort of closed system, in which one or more non-fluid dynamic forces have modulated the flow field.

The only "non-fluid dynamic forces" in the atmosphere (and especially in thunderstorms) are electromagnetic. So while the vacuum vortex is caused by fluid dynamic factors (i.e., the low pressure inside the cloud), the constriction of the radius at the ground can only be due to EM factors, as they are the only other physical forces present.

For EM factors to influence the behavior of air in a fluid dynamic vortex, they (obviously) have to be capable of exerting forces on the air. Since air is only infinitesimally responsive to the magnetic force, it can be confidently ruled out. Hence the constriction of the radius at the bottom can only be due to the electric force. We can also say with absolute certainty that for the electric force to alter the behavior of the air, the air has to be charged.

Because the tornadic inflow is clear, we know that it is free of water aerosols and rain drops. Relative humidity readings in the air are typically ~20%, meaning that the water content is less than .2% by volume. Liquid and solid water particles are the primary negative charge carriers in the storm, while the gaseous nitrogen and oxygen molecules are not good at hosting net negative charges. Hence the absence of liquid or solid water particles in the tornadic inflow suggests that any substantial space charge would have to be positive, not negative. This will be confirmed by other means later, but it is more straightforward to identify the sign of the space charge when first acknowledging that the air is, in fact, charged.

All other factors being the same, there are many ways that a space charge could influence the behavior of a gas, but we can limit the solution domain to only one possibility if we stick closely to definitions. We know that we are attempting to explain the constriction of the radius of a vacuum vortex, away from the source of the low pressure, with the fastest air speeds where friction is the greatest (i.e., on the ground). While such is impossible in an open thermodynamic system, these are the defining characteristics of a bottleneck flow in a closed system. (See Figure 2.)

Bottleneck Vortex
Figure 2. A fluid pulled through a bottleneck has its fastest speed and lowest pressure at the bottleneck.

The air flows the fastest through the bottleneck, as the same volume of air has to move at a greater speed to get through a smaller aperture. In an ideal gas, with no friction, there would be no pressure gradient. But skin friction at the bottleneck increases with the square of the velocity, and this impedes the flow of air. Once past the bottleneck, the air accelerates rapidly, leaving an extreme low pressure at the bottleneck. Then the low pressure relaxes as the air approaches the source of the low pressure. Demonstrations of such behaviors use an apparatus similar to that in Figure 3.

Vortex Apparatus
Figure 3. An apparatus that creates a bottleneck vortex.

Figure 4 shows the results at different "swirl ratios" (i.e., the angular velocity divided by the vertical velocity). In the 1st panel, slight angular velocity enables a narrow vortex that stays organized. In the 2nd panel, with a larger swirl ratio, we see a phenomenon known as "vortex breakdown." Rotating rapidly while surrounded by stationary air, the vortex is subjected to friction, which begets turbulence. This allows the surrounding air, which lacks centrifugal force (because it is not rotating), to flow into the vortex. Once inside, it seeks the extreme low pressure at the base. A "downdraft" inside the vortex relieves the low pressure, and thereby reduces the centripetal force. This results in the rapid widening of the vortex just prior to its breakdown. Note that even in tightly-controlled conditions, this configuration is extremely unstable. In the 3rd panel, with an even higher swirl ratio, vortex breakdown occurs at soon as the air exits the hole. And in the 4th panel, the turbulence is so robust that it shrouds the vortex.

Vacuum Vortexes
Figure 4. Laboratory demonstration of laminar and turbulent vortexes, courtesy C. R. Church.

All of these distinctive forms have been observed in tornadoes.

Bottleneck Vortex Comparison 1
Figure 5. Vortex breakdown midway through the vortex. Note the evaporation as the low pressure relaxes in the direction of the flow.

Bottleneck Vortex Comparison 2
Figure 6. Vortex breakdown just above the boundary.

Bottleneck Vortex Comparison 3
Figure 7. Vortex breakdown shrouded by turbulence that it created.

So the laboratory research demonstrated that vortex breakdown can only occur if the low pressure is relaxing in the direction of the flow, and that the fastest air speeds occur at the lower boundary, not in spite of skin friction, but because of it, as this is what creates the bottleneck. The researchers successfully recreated all of the distinctive tornadic forms, but they failed to demonstrate how the properties of bottleneck vortexes were relevant to the study of tornadoes, which are assumed to be open systems, incapable of bottleneck flows. The reason is that in the 1970s, they did not have the EM data and the EHD principles necessary to understand how the electric force could introduce closed-system properties into an atmospheric vortex. This can now be accomplished.

We have already acknowledged that the tornadic inflow is charged, and that this somehow results in the constriction of the radius at the ground. We have seen that in a bottleneck flow, the constriction comes from skin friction at the bottleneck. So we know that for charged air to create a bottleneck flow, somehow it has to accentuate skin friction. If the air is charged, it will induce an opposite charge in the ground, resulting in an attractive force. With the air pulled down to the ground, skin friction then impedes the flow, producing the bottleneck.

Open & Closed Vortexes
Figure 8. Vortexes, open & closed.

We only need one more piece to have a complete description of the phenomenon. In the laboratory apparatus, the air encountered skin friction as it moved toward and through the lower aperture. In a tornado, the air encounters skin friction as it moves along the ground. But we need an "aperture" in which the inflow is released from its attraction to the ground — otherwise, the air would simply cling to the ground, and the low pressure aloft would get its air from elsewhere.

The properties of this "aperture" can be deduced with confidence. There is no changing the conductivity of the Earth, which supports an induced charge if exposed to charged air. So the only way to release the air from its attraction to the ground is to neutralize its charge. To neutralize a space charge, we need an equal supply of the opposite charge. We previously identified the sign of the space charge as positive. So we need a supply of electrons to neutralize the positive charge in the tornadic inflow.

There are two possible sources of electrons, and there is evidence that both are active electron donors. The first is the Earth itself. But it is not a flow of free electrons out of the Earth. Very few of the molecules in the tornadic inflow actually come into contact with the ground. Those get neutralized, but the neutralizing electrons do not spread readily through the low conductivity of the air. The most effective charge neutralization comes from charged dust that is lofted by the electric force into the tornadic inflow. This produces a mixture of positive and negative ions, where the charges haven't actually recombined, but the electric force binding the air to the ground is effectively neutralized, because the mixture is net neutral. The other electron donor is the massive negative charge region inside the storm, and somewhat surprisingly, this appears to be the more reliable source of electrons. The reduced pressure inside the vortex lowers the electrical resistance, thereby enabling a faster Townsend avalanche. The electrons can also flow faster through condensed water in the vortex wall than they can through the clear air at the ground. The electron drift within tornadoes has been confirmed by the magnetic field that it generates, by radio frequency interference, and in extreme cases, by glow discharges within the vortex. All of the data indicate that the current density is in the range of 100~250 amps.^1,2,3,4

So the tornadic inflow is positively charged, hence it induces a negative charge in the Earth, and is thereafter attracted to the Earth, until the charges are neutralized, near or inside the vortex, at which time the air is free to ascend. Thus the electric force, and the neutralization thereof, instantiate a bottleneck vortex in the atmosphere.

Tornadic Potential
Figure 9. Tornadic potential energy is the product of the electric force holding the air down, when it would have curved upward in response to the low pressure aloft.

References

1. Winn, W. P.; Hunyady, S. J.; Aulich, G. D., 2000: Electric field at the ground in a large tornado. Journal of Geophysical Research, 105(D15): 20145-20153

2. Brook, M., 1967: Electric Currents Accompanying Tornado Activity. Science, 157(3795): 1434-1436

3. Watkins, D. C.; Cobine, J. D.; Vonnegut, B., 1978: Electric Discharges Inside Tornadoes. Science, 199: 171-174

4. Berson, F. A.; Power, H., 1972: On the geo-electromagnetic aspects of tornado initiation. Pure and Applied Geophysics, 101(1): 221-230

[captain swoop]

OK so now show some evidence of that these charges and currents are the cause of the vortex rather than just being results.

I don't see anything in what you have written here apart from you asserting they are.

[Shaula]

Also some calculations or modelling to show that the observed charges are strong enough to produce the effects you assert would be useful - I'd be surprised if the charge is strong enough to have that kind of physical effect.

[CharlesChandler]

OK so now show some evidence of that these charges and currents are the cause of the vortex rather than just being results. I don't see anything in what you have written here apart from you asserting they are.

I don't really understand your comments. The observable evidence in question is that in a tornado, the narrowest radius is the furthest from the source of the low pressure. Everybody knows that, but nobody sees it as "evidence" of anything. They just take it for granted, that this is the way tornadoes are, but it doesn't tell us anything about the forces at work. Yet to me, it tells the whole story. So there is sufficient evidence to support the proof.

The proof that the electric force is responsible is that it is the only possibility. (If fluid dynamics cannot explain it, such constitutes rigorous proof of the presence of one or more non-fluid dynamic forces. In the relevant environment, there are only two non-fluid dynamic forces: the magnetic force, and the electric force. The magnetic force is eliminated because of its extremely weak interaction with air. That leaves the electric force as the only legitimate candidate.) As concerns how the electric force does the deed, attention is called to the fact that by definition, an extreme low pressure, away from the source of the low pressure, is only possible in a bottleneck flow. The rest was derived from there, and constitutes definitive proof. (Most of what passes for proof in this world is not proof at all. But this actually is proof, because it's by definition, wherein all other possibilities have been eliminated.)

Also some calculations or modeling to show that the observed charges are strong enough to produce the effects you assert would be useful - I'd be surprised if the charge is strong enough to have that kind of physical effect.

Let's run the numbers for an EF1 tornado (with 40~50 m/s winds). Since these are far and away the most common, the data are more reliable.

In the OP I noted that the current within the tornado is in the range of 100~250 amps. We'll use the lower number.

By atmospheric standards, 100 amps is actually a lot of current. The current in a lightning strike can exceed 10,000 amps, but only for a thousandth of a second. If there was 1 strike every second, that would be an average of 10 amps. At one strike every 30 seconds, we have only .3 amps, and 100 amps sounds like a big number. Yet supercell thunderstorms are highly electrified, and have been recorded issuing over 25 strikes per second. Furthermore, while the tornado is active, the lightning strike rate falls to near zero,^5,6,7,8 suggesting that the tornado is draining the charge that otherwise would have produced lightning. The area experiencing the lightning deficit due to the tornado is typically 10 km², which is the size of the supercell itself. If we consider 25 strikes per second to be extreme, but 10 strikes per second to be more typical, and if all of that current is in a Townsend avalanche or glow discharge within the tornado instead of arc discharges, sustained 100 amp currents become possible. To look at it another way, the total charge in a supercell has been estimated at 100,000 Coulombs.² 100 amps equals 100 Coulombs per second. At that rate, it would take 1,000 seconds to drain all of the charge out of the cloud. That's 17 minutes, which is the typical duration of a tornado.

When viewed from another angle, 100 amps seems like too weak of a current to do anything at all. An EF1 tornado expends approximately 5 MW of power on the ground. 100 amps is not directly responsible for that power.

But the significance of the current is not that all of it is thermalized, thereby generating all of the power spent on the ground. In fact, only a vanishingly small amount of thermalization occurs near the ground at the point of charge recombination. Rather, the current releases the tornadic inflow from its attraction to the ground. In other words, it provides the hole that enables the continuous flow through the bottleneck. The bulk of the power expended on the ground is just an artifact of the buoyancy of the air inside the vortex. There, the 100 amps does have a thermal significance. If the tornado is 300 m tall, and if the electric field is 5 kV/m,^1,9,10 we can then estimate the resistive heating from the current flowing through the tornado.

• volts = 300 m × 5,000 V/m = 1,500,000 V
• watts = amps × volts = 100 × 1,500,000 = 150,000,000 W

150 MW of resistive heating inside the vortex is the primary source of buoyancy, and is roughly twice the power of latent heating from condensation inside the tornado. The 5 MW that is lost to skin friction at the ground is small by comparison.

Given the current density, and assuming that the current is neutralizing the space charge in the tornadic inflow, if we know the charge density of the air, we can calculate how much charged air would have to be flowing into the tornado to absorb all of that current. Previous research estimated the number of charged particles in the tornadic inflow to be one part per billion (2.14 × 10¹⁴ charged particles/m³), and the charge per particle to be 3.2 × 10⁻¹⁷ C.¹¹

• space charge = 2.14 × 10¹⁴ × 3.2 × 10⁻¹⁷ = 6.8 × 10⁻³ C/m³

The result is realistic, but the researchers assumed that the charges would be borne by microscopic aerosols (Ø 0.02 µm), which as noted in the OP does not agree with the typical relative humidity readings. If we assume that the charged particles are all molecular ions missing only one electron, a reasonable estimate would be one part per million.

• molecules in a cubic meter of air = 1 × 10²³
• one charged molecule per million = 1 × 10¹⁷ ions/m³
• 1 coulomb = 1.6 × 10¹⁹ electrons
• space charge = (1 × 10¹⁷ ions/m³) / (1.6 × 10¹⁹ electrons/coulomb) = 6.25 × 10⁻³ C/m³

So this way, we get 6.25 × 10⁻³ C/m³, which agrees with the estimate of 6.8 × 10⁻³ C/m³ from previous research. So let's see how much air, at that charge density, it would take to absorb 100 amps of current.

• at 6.25 × 10⁻³ C/m³, 1 coulomb = 1 / 6.25 × 10⁻³ m³ = 160 m³
• 1 amp = 1 coulomb / second
• current = 100 amps = 100 C/s = 100 × 160 m³/s = 16,000 m³/s

With that as the volume, we can then determine the horizontal velocity of the inflow.

• depth of inflow layer = 1 m
• circumference of tornado 100 m wide = 314 m
• cylindrical surface of vortex mouth = 314 m²
• velocity of inflow = 16,000 m³/s / 314 m² = 50.96 m/s

50.96 m/s is just barely into the EF2 range, which would seem appropriate for an electric current at the low end of the 100~250 amp estimates.

The current could actually be a lot less, if the space charge was less. If the air is clinging to the ground because of an electrostatic attraction, but picking up 5 MW of thermalized skin friction, we know that the minimum amount of charge to maintain this configuration will be the charge that can keep the air clinging to the ground, despite the buoyancy that results from 5 MW of heat.

First we'll consider the force of the electric field that is pulling the air toward the ground.

• electric field = 5 kV/m
• newtons = coulombs × electric field = 6.25 × 10⁻³ × 5,000 = 31.25 N/m³

Next we'll assume an inflow rate of 1,000 m³/s for an EF1, and apply 5 MW of heat to it, and see what that does to the temperature. Raising the temperature of 1 m³ of air by 1 °C in 1 second requires approximately 1,340 watts.

• watts per m³ of air = 5 MW / 1,000 m³/s = 5,000 W/m³/s
• temperature difference = 5,000 W/m³/s / 1,340 W/°C/m³/s = 3.73 °C

From the temperature difference, we can calculate the buoyancy.

• mass of air at STP = 1.2 kg/m³
• newtons = kilograms / 0.101971621
• gravitational force at STP = 1.2 / 0.101971621 = 11.77 N/m³
• standard temperature = 15.6 °C = 288.75 K
• after frictional heating = 288.75 K + 3.73 = 292.48 K
• temperature ratio = 288.75 / 292.48 = 0.987246991
• gravitational force after heating = 11.77 N/m³ × 0.987246991 = 11.62 N/m³
• buoyancy = 11.77 N/m³ − 11.62 N/m³ = 0.15 N/m³

With a downward electric force of 31.25 N/m³, and an upward buoyancy of only 0.15 N/m³, that's 208 times more electric force than buoyancy. With 2 orders of magnitude less electric force, the air would still stay near the ground until the electric charges are neutralized. So we'll consider 6.25 × 10⁻⁵ C/m³ to be the minimum space charge necessary to hold the air down as it is heated by friction. That's only 1 part per 100 million, and which will only take 1 amp of current to neutralize.

References

1. Winn, W. P.; Hunyady, S. J.; Aulich, G. D., 2000: Electric field at the ground in a large tornado. Journal of Geophysical Research, 105(D15): 20145-20153

2. Brook, M., 1967: Electric Currents Accompanying Tornado Activity. Science, 157(3795): 1434-1436

3. Watkins, D. C.; Cobine, J. D.; Vonnegut, B., 1978: Electric Discharges Inside Tornadoes. Science, 199: 171-174

4. Berson, F. A.; Power, H., 1972: On the geo-electromagnetic aspects of tornado initiation. Pure and Applied Geophysics, 101(1): 221-230

5. Buechler, D. E.; Driscoll, K. T.; Goodman, S. J.; Christian, H. J., 2000: Lightning activity within a tornadic thunderstorm observed by the optical transient detector (OTD). Geophysical Research Letters, 27(15): 2253-2256

6. Murphy, M. J.; Demetriades, N. W., 2005: An analysis of lightning holes in a DFW supercell storm using total lightning and radar information. Conference on Meteorological Applications of Lightning Data, 2.3

7. Steiger, S. M.; Orville, R. E.; Carey, L. D., 2007: Total Lightning Signatures of Thunderstorm Intensity over North Texas. Part I: Supercells. Monthly Weather Review, 135: 3281-3302

8. Trostel, J. M.; Matthews, J., 2010: Application of an Improved SCIT Algorithm to Investigate Lightning Characteristics of a Tornado Outbreak in Georgia. 26th Conference on Interactive Information and Processing Systems (IIPS) for Meteorology, Oceanography, and Hydrology

9. Freier, G. D., 1959: The Earth's Electric Field during a Tornado. Journal of the Atmospheric Sciences, 16(3): 333-334

10. Gunn, R., 1956: Electric field intensity at the ground under active thunderstorms and tornadoes. Journal of the Atmospheric Sciences, 13: 269-273

11. Dehel, T. F.; Dickinson, M.; Lorge, F.; Startzel, R., Jr., 2007: Electric field and Lorentz force contribution to atmospheric vortex phenomena. Journal of Electrostatics, 65(10–11): 631-638

[Shaula]

Your assumption in your calculations is that all the electrical energy is converted into heat. Given that the whole reason it called a glow discharge is because it glows due to electronic transitions why do you believe that the heating efficiency is 100% in this special case?

[CharlesChandler]

Your assumption in your calculations is that all the electrical energy is converted into heat. Given that the whole reason it called a glow discharge is because it glows due to electronic transitions why do you believe that the heating efficiency is 100% in this special case?

Glow discharges inside tornadoes are extremely rare. They have only been successfully photographed once.

Two luminous tornadoes that did F4 damage in Toledo, OH, 1965-04-11, courtesy James R. Weyer.

It's possible that the discharges are only robust enough for luminosity in the most extreme cases. Then, of course, it's true that some of the watts go out in visible photons, but there are no data for how many watts that might be. There are also a few watts that go out in radio frequency interference. (If the tornado is within 1 km, the sferics can be detected by a TV set.) But I say "a few watts" because the tornado has to be very close. Somebody might have more precise numbers, but nobody is currently contending that the photonic power is sufficient to do anything except cause static in a nearby receiver. (In the 1960s, one researcher attempted to demonstrate that the energy transport mechanism, from the cloud down to the ground, was RFs generated by a ring current in the cloud.¹ But the work was based entirely on some very rare cases, and we can safely say now that the researcher's extrapolations were out of range.) In the more typical cases that support only Townsend avalanches, the amount of potential that is not thermalized inside the tornado is insignificant, and thinking that all 150 MW in a small tornado contribute directly to the buoyancy is not terribly unreasonable.

I'd like to elaborate a little bit on the general scheme here, as there is a counter-intuitive piece to it that you won't get unless you think really hard about it, or I help lay it out for you. The 5 MW of power lost to skin friction on the ground are in no respect coming from the electric current. The skin friction is caused by air moving along the ground as it approaches the tornado, accentuated by the electrostatic potential that keeps the air traveling along the ground, despite the buoyancy that it picks up (+3.73 °C = 0.15 N/m³ of buoyancy, which should have hoisted the heated air out of the inflow). The electric current eliminates that electrostatic attraction of the inflowing air to the ground, enabling an updraft inside the vortex, and releasing that thermal potential. This causes the rapid upward acceleration of air at the base of the tornado, where the heated air seeks its equilibrium point ~50 m above the ground. The buoyancy that results from skin friction is small compared to the other heat sources inside the tornado, but it is the one potential that gets released entirely at the base of the vortex, and this is responsible for the extreme low pressure at the ground.

To highlight the counter-intuitive aspect of tornadoes, we should start at the other end, up in the cloud. Thinking of a tornado as a vacuum vortex, we orient our thoughts around the source of the low pressure, which is the updraft inside the cloud. But once in that framework, we are hard-pressed to understand how a vortex in the inflow encounters a bottleneck on the ground. Remember, we're talking about an open-air system. I can establish how a space charge in the tornadic inflow can hold the air down to the ground, where it develops thermal potential due to skin friction. And I can show that the electric current inside the tornado neutralizes the space charge, enabling an updraft. But starting from the low pressure aloft, and since it's an open-air system, air not involved in the bottleneck should flow more freely toward the pressure deficit aloft.

Analogously, if I open a door 1 cm, to give just a crack through which air can rush, and then stand 10 m away with a vacuum cleaner hose pulling in air at 10 m/s, I'm not going to get air rushing through the crack in the door in a bottleneck flow responding to the low pressure in the vacuum cleaner hose. The reason is that there is too much distance between the vacuum cleaner hose and the door, and the vacuum is more easily satisfied by air that does not have to get through the bottleneck in the cracked door. And this is the problem in understanding a tornado. There might be a 50 mb pressure deficit inside the cloud. But how does the low pressure project all of the way to the ground and start fighting skin friction there?

The answer is that the centrifugal force in the vortex creates a "sealed pipe" that allows the low pressure to project away from the source of the low pressure, until it hits a boundary, where it will be truncated.

But that doesn't explain how a bottleneck at the boundary will result in a further reduction in pressure, as this should not be possible. It also doesn't explain how the low pressure is piped down to the ground after vortex breakdown, when the centrifugal seal is no longer present.

To get this sorted out, we have to acknowledge that the centrifugal force does, indeed, seal the pipe, but there are also heat sources inside the vortex. Roughly speaking, we have 150 MW of resistive heating, and 50~100 MW of latent heating (due to the condensation of water vapor in the vortex). With 200+ MW of heat inside the vortex, it's not a simple vacuum vortex anymore. It's generating its own low pressure. Now take a long look at this image (cited previously):

Vortex breakdown just above the boundary

On the left side, we see a vacuum vortex inside a sealed chamber, where the air passes through the bottleneck because that's the only opening. But on the right side, we see a tornado in the open air. It's definitely a bottleneck vortex, but how does the low pressure aloft pull air through the bottleneck, instead of from elsewhere? And where is the sealed pipe that is transporting the low pressure down from the cloud?

The answer is that the low pressure aloft is not the main source of energy, and might not even be present in a mature tornado. Rather, it's energy conversions inside the vortex itself that are powering the tornado. Resistive and latent heating, and a little bit of skin friction at the ground, produce the buoyancy necessary to sustain the updraft, and the centrifugal force consolidates all of the conversions within the vortex.

References

1. Silberg, P., 1966: Dehydration and Burning Produced by the Tornado. Journal of the Atmospheric Sciences, 23: 202-205.

[publiusr]

http://www.energycompressibility.inf...adogenesis.htm

I seem to remember Kurt Vonnegut's relative Bernard Vonnegut had ideas about electric tornadoes.
http://en.wikipedia.org/wiki/Bernard_Vonnegut

He was awarded an Ig Nobel Prize in 1997 for his paper "Chicken Plucking as Measure of Tornado Wind Speed."
That was most likely from "flight molt," as per Tom Grazulis of www.tornadoproject.com
http://www.tornadoproject.com/oddities/odditys.htm

Yet in his book:
http://www.amazon.com/Significant-To.../dp/1879362031
There is an old photo of what looks like two glowing column shaped tornadoes. I think they might have been search lights looking for a funnel...hard to tell.

In Tornado Video Classics, we see Sterling Colgate firing rockets into a tornado--or trying to, rather...
http://www.youtube.com/watch?v=2UkhE_Hmozc

He was trying to prove an electric tornado theory I think: http://www.youtube.com/watch?v=2UkhE_Hmozc
We know that sferics can be real--even as you can listen to meteors with radio reflectivity..
http://www.kilty.com/t_elec.htm

The biggest find is that tornado wind speeds do not have to be as great as once thought to do damage. Once people thought tornado wind speeds approached the sonic range--but you don't need F-5 winds to do F-5 damage. Thus the Enhanced Fujita (EF-) scale of today.

If tornado wind speeds are lower, one might call into question the tornado as generator theory. Sometimes, storms only show a mezocyclone as they go tornadic. There is an idea that tornadoes are spun up by smaller invisible funnels near an updraft. More bottom up than top down as per some... We saw Jarrell start off as a landspout and back into a more favorable environment and just explode into growth.

Still, the ideas of sprites and elves and jets still interest me. Maybe Sterling was on to something--but not many think so now... Count me skeptical.

Storm Chaser and Warning efficacy researcher Matt Biddle holds that there is no such thing as ball lightning, even though it has been talked about in even a few skeptical magazines. Lightning running toward you, or perhaps a lightning stroke breaking up into beads fools some. There are even folks who question the will o the wisp, as being a glowing fungus that might adhere to night owls plumage and scare folks when it flies above foxfire....

I was fortunate enough to assist Matt in his recent trips to Alabama, in 1998
http://www.colorado.edu/hazards/rese...116/qr116.html
http://www.stormtrack.org/library/archives/stnov00.htm

And just last year
http://stormeyes.org/wp/2011/04/dixi...iate-thoughts/

[CharlesChandler]

From the web-page you cited at the beginning of your post (Tornado-genesis by an Isentropic Energy Transformation), with my bolding:

It was a fine, warm sunny morning with little or no wind. At about 11 a.m. my wife suddenly called out in alarm at the sudden appearance out of nowhere of a small, whirling, column of mist over the water in a small bay about 100 meters from our boat and about 50 meters from the wooded shoreline. The swirling mist column was about 2 meters feet high and 1.5 meters in diameter, embedded in a larger patch of disturbed surface water about 8 meters in diameter. The mist column was whirling round and round violently and emitting a hissing sound. After about 10 to 15 seconds in the same location it disappeared as suddenly as it had formed, leaving only a small darkened, breeze- ruffled area on the surface of the water which then drifted away across the lake at about 10 km/hr toward the eastern shore. This lake is shallow, not over 7 meters or so deep at the deepest spot. Inspection of the little bay where the whirlwind had erupted showed no signs of any disturbance in the water itself which was perfectly clear right down about a meter or so to the lake bottom. Obviously the whirl had been in the air above the water only. The lake water was cool at around 18 ˚C. The air temperature was warm at about 25˚C (24 to 26˚C).

With little or no wind, there is no instability in the atmosphere, and adiabatic updrafts are not possible. This is especially true if the lower boundary (in this case, a lake) is a heat sink, and the air at the bottom is unusually cool, and therefore more dense than usual. And condensation is not a self-sustaining energy source at this scale. Once water vapor starts condensing, the air is dryer, and its temperature is increased by latent heating. Both factors widen the gap between the wet and dry bulb temperatures. Hence at a fixed elevation, condensation is self-extinguishing. This leaves him with a perfectly stable situation where the forces prevent energy conversions. And it doesn't matter that there is little friction. Changing it to an isentropic conversion doesn't create energy where there was none.

For me, the "hissing sound" (that he reports but does not explain) is the key. That's the sound of a corona discharge. My guess is that the abundant sunlight manufactured some positive ions in the surrounding hills, which convened in the bay, attracted to the conductivity of the water. When the electrostatic potential became sufficient, a discharge began, which produced the heat necessary for an updraft, as well as the hissing sound. It's an improbable explanation, but that's appropriate for an extremely rare event. And it has an energy source.

Bernard Vonnegut had ideas about electric tornadoes.

Vonnegut did a lot of work. Most notably for my purposes, he studied the interaction between a vortex and an electric current, which form a positive feedback loop. The reduced pressure inside the vortex allows the passage of more current, while the current heats the air, contributing to the buoyancy, which enhances the vortex. He demonstrated that in conditions insufficient for a vortex and for a glow discharge, with a weak pressure gradient and a weak voltage, the positive feedback resolves into a well-defined vortex and a robust current.

Yet in his book [...] there is an old photo of what looks like two glowing column shaped tornadoes. I think they might have been search lights looking for a funnel...hard to tell.

Vonnegut researched this, and no, there weren't any search lights there, nor any other artificial light source. So the luminosity had to be coming from the tornadoes themselves. To my knowledge, this is the only time this luminosity has been photographed.

The biggest find is that tornado wind speeds do not have to be as great as once thought to do damage. [...] If tornado wind speeds are lower, one might call into question the tornado as generator theory.

The one piece that is present in my work, and not in any other (thermodynamic or electromagnetic), is an accounting for the bottleneck properties. Resistive heating through the 1 km height of the tornado isn't going to create a bottleneck flow at the ground. That's just going to create a vortex that will act like it's responding to an even greater pressure deficit inside the cloud, as the thermalization will be distributed throughout the entire height. The same goes for latent heating, which continues well up into the cloud, and therefore does not release all of its heat just at the ground. The extreme low pressure at the ground is the source of the destructive power of the tornado, but because people don't understand, the significance of this fact is not addressed in their treatment of the topic. Yet it's the key to the whole thing. Without a bottleneck, none of the energy conversions identified anywhere in the literature would produce a tornado.

[Shaula]

If we consider 25 strikes per second to be extreme, but 10 strikes per second to be more typical, and if all of that current is in a Townsend avalanche or glow discharge within the tornado instead of arc discharges, sustained 100 amp currents become possible.

Glow discharges inside tornadoes are extremely rare. They have only been successfully photographed once.

So according to your argument no current flows, which rather hurts:

The electric current eliminates that electrostatic attraction of the inflowing air to the ground, enabling an updraft inside the vortex, and releasing that thermal potential.

So basically it looks like you double count the electrical energy, or at the very least ignore all other forms of dissapation to get that 150MW figure.

Townsend avalanches only happen over a small range of voltage/current combinations - they tend to evolve into glow discharges pretty fast. What mechanism do you propose keeps the system within these limits? Or is there something that prevents glows from occuring?

[CharlesChandler]

So according to your argument no current flows...

No, the "current" is there, though it definitely isn't an arc discharge, and is only a glow discharge in rare cases. Some people would prefer to call it simply an electron drift. The direct evidence of the drift is in the magnetic fields that it generates. See:

Brook, M., 1967: Electric Currents Accompanying Tornado Activity. Science, 157(3795): 1434-1436

There hasn't been any follow-up on this line of evidence, since in the early 1970s, there was a major paradigm shift, from the physics of tornadoes, to probabilistics. But I know of two other unpublished efforts, one by a scientist and another by an engineer, which detected the same magnetic field. Other lines of evidence include sferics and telluric currents. This study was focused on lightning, but there happened to be a tornado there, and they observed a direct correlation between the tornado and in-ground currents:

Winn, W. P., Hunyady, S. J., and Aulich, G. D., 2000: Electric field at the ground in a large tornado. Journal of Geophysical Research, 105(D15): 20145-20154

Townsend avalanches only happen over a small range of voltage/current combinations - they tend to evolve into glow discharges pretty fast. What mechanism do you propose keeps the system within these limits? Or is there something that prevents glows from occurring?

Nothing is going to prevent the discharge from stepping up to glow mode, if the voltage/resistance allows it. But the electric field under a supercell thunderstorm is typically something like 5 kV/m. That will produce only a dark discharge. A glow discharge requires 100 kV/m at STP. This happens, and is called St. Elmo's Fire when it occurs in the atmosphere. But it is rare. In the reduced pressure inside the tornado, a glow discharge can occur at lower volts, but again, it's rare, so it doesn't figure significantly in my work.

[CharlesChandler]

No more criticisms??? Whaaaaaa... Four years ago I fired up a thread here on tornadoes. I didn't know what I was talking about, but I knew which direction I was headed, and I just wanted to see who else might be headed in that direction. Not knowing what I was talking about, I got flamed really bad. But I've done a lot of work since then, and I guess now I pass the test, at least if the lack of flamings are any indication.

Nevertheless, I'll criticize myself if that's the only way to make progress, and I'd like to clarify a few points. In post #4, I said that supercell thunderstorms have been recorded issuing 25 lightning strikes per second. At 10,000 amps apiece for 1/1,000 second, that would be 10 amps per second per strike, for a total of 250 amps of continuous current. That was a bit misleading, and I don't want others investigating these issues to see an uncorrected misrepresentation. First, using record-setting numbers for a general theory is always questionable. Second and more significantly, more than 90% of the lightning "issued" by a highly electrified supercell is cloud-to-cloud lightning, and does not speak to the total charge transfer between the cloud and the ground. Hence the amps in a typical cloud-to-ground strike (i.e., 10,000) multiplied by a record-setting cloud-to-cloud strike rate (i.e., 25/s) is a bit of an undistributed middle, and does not prove that such energy is available to drive a tornado.

There is definitely a current inside the tornado. Some researchers have actually maintained that it was a lot more than what I'm saying. Brook (1967) found the magnetic field generated by a tornado to be 1.5 × 10⁻⁸ teslas, using a magnetometer from a distance of 9.6 km. From this we can calculate the amps.

• permeability of air = 4 π × 10⁻⁷ N/A²
• amps = teslas × 2 π r / permeability
• amps = (1.5 × 10⁻⁸ × 2 × 3.14 × 9600) / (4 × 3.14 × 10⁻⁷) = 720 A

The magnetic field was sustained for over 15 minutes, and showed a distinct "step-up" that coincided with the touch-down of the tornado, and it dropped back to near the resting field density when the tornado broke up. There were also beginning and ending peaks in the field strength, between which the field maintained the 1.5 × 10⁻⁸ teslas.

Yet 720 amps, sustained for 15 minutes, is ridiculous. It was high-precision equipment that recorded these numbers, but the charge densities in the cloud necessary to support the charge separation that could move that many Coulombs are off the charts. Subsequent research that acknowledged the validity of the raw data challenged the conclusions. IMO, there is a lot that we don't know about the charge structure of supercell thunderstorms, and I am convinced that a massive amount of charge is recirculating within the storms. So I don't think that Brook was measuring a discharge, but rather, a recirculation (driven by the thermodynamic factors at play) that just happened to be bearing charged particles, creating a poleless current. So instead of 300,000 Coulombs getting transferred in 15 minutes, it might have been 50,000 Coulombs in a thermodynamic recirculation of air. The step-wise behavior of the magnetic field is then an artifact of the polarization of the charge structure caused by the tornado. There is no question that there is a low pressure inside a tornado, and this low pressure alters the conductivity of the air. Neighboring charges sense this conductivity at the speed of light, and become polarized by it. Now all of a sudden, the entire storm is generating a unified magnetic field that Brook records at 1.5 × 10⁻⁸ teslas, and which coincided with the birth and death of the tornado. But that doesn't mean that 720 amps were flowing through the tornado.

At the end of post #4, I corrected myself in demonstrating that the critical charge density for a tornado is simply a space charge capable of overpowering the buoyancy resulting from thermalized skin friction. Here again I'd like to call attention to this image:

Vortex breakdown just above the boundary

Remember that a vortex is not an entity -- it is a condition in a medium, and in order to understand the vortex, we have to neglect the vortex and study the medium instead. The important thing in this image is not what we see (i.e., the vortex), but what we don't see (i.e., the clear-air inflow). Imagine that you're the air, and ask yourself why you would accelerate that rapidly on entering a vortex on the ground, where the friction is so much greater. The only possible answer is that you're being drug along the ground, and friction is impeding your progress. As soon as you get inside the vortex and get lifted above the ground, the friction is gone, and you can freely manifest your thermal buoyancy. So we know that whatever force keeps the air near the ground, it has to be more powerful than the 0.15 N/m³ of buoyancy coming from 5 MW of thermalized skin friction. This only necessitated a space charge of 6.25 × 10⁻⁵ C/m³ (1 part per 100 million) in air flowing at 1,000 m³/s, which would only require 1 amp to neutralize.

So the incredible thing here is not that tornadoes are powered by an impossible 720 amps of sustained current. Rather, it's that an EF1 tornado expending 5 MW on the ground is made possible by a space charge that is neutralized by only 1 amp of current (at minimum). Nevertheless, this amount of current is easily within range for a moderate thunderstorm, and the behavior of the vortex taking this into account makes sense, while not taking this into account leaves the tornado making no sense whatsoever.

There is just one other point I'd like to make before moving on. We have a bottleneck flow, wherein charged air is being drug along the ground, impeding its progress, and building up thermal potential as it goes. When neutralized by the current inside the tornado, the thermal potential is released, and a vigorous updraft results. But working backwards from the source of the energy (i.e., the thermal buoyancy), why did the updraft choose to pull air along the ground, instead of from above? Videographic evidence shows that the inflow layer is extremely shallow. Most researchers say that it is no more than 10 m deep, while I'm inclined to believe that it might be only 1 m deep, and that's the number I use in my calculations. So why doesn't the updraft inside the tornado tap into air more than 1 m above the ground, which experiences a lot less friction, and which has no affinity for the ground, because it is not charged? This is a problem for any tornado theory, but especially for a theory that asserts that something is pulling the air down to the ground, accentuating skin friction.

There is only one possible answer to that question. Charged air has a much lower viscosity. Electrostatic repulsion prevents the particle collisions that instantiate friction. Of course, at 1 charged particle per 100 million, this isn't pure plasma, which would behave as an ideal gas because of the microphysics. But at the macroscopic level, even weak space charges discourage the transition to turbulence, which is the main source of friction in the air. So the charged air flows more freely. All other factors being the same, a shallow inflow layer moving rapidly along the ground would be the path of greatest resistance, which is generally the road less traveled in natural phenomena. But all other factors are not the same, and low-viscosity air is channeling through high-viscosity air to get to the low pressure, developing 5 MW of thermal potential as it goes.

Thanks so much for the comments, 4 years ago and now. I never would have been able to work all the way through this without the benefit of the diverse talents on this board.

Now, if we're done here, I'll start preparing the OP for a new thread on the next related topic, which is dust devils (terrestrial and Martian), which are distant cousins of tornadoes.

Cheers!

[Shaula]

I think my main criticism is still there I am just not good enough with electricity to articulate it properly or argue it fully! Your heating effect is far too large, I think. You seem to say all the energy in the current is converted to heat. I just don't see that. If it were that good/easy the ionosphere would be far hotter! But electricity is my big weak spot in physics.

[CharlesChandler]

Do you know of anybody else who might want to take a crack at it? EHD is a fringe discipline, but I figured that I'd find more people with knowledge of it on an astronomy board than anywhere else. That's why I'm here, instead of on a meteorological board, because it's totally outside of their field of focus. All I get out of them is, "That's not how we do things." And the EEs who have looked at this didn't understand enough about fluid dynamics to realize the significance of the interplays that I'm describing. Regardless, I think that I have a legitimate scientific advance in the making, and I'll continue to seek critical reviews wherever I can get them. But only people with knowledge of both fluid dynamics and EM (such as plasma physicists) are going to "get it."

[Shaula]

There are some plasma physicists on here - but I am not sure how many of them read this section of the forum.

What might be putting people off is the sheer length and 'wall of text' effect of your post. If you want to have it looked at more clearly then presentation is a big thing.

Break out your post into sections, provide equations rather than things like "newtons = coulombs x electric field". That is the crux of my issue with your heating equation. P=IV describes the electrical power of DC. You are essentially claiming that is converted to heat with 100% efficiency. P=I^2 R might be a better fit if you assume that air breaking down acts like an Ohmic resistor.

Small note 150MW of resstive heat requires the air to have a resistance of 15,000 ohms at 100 amps. A quick look around gave a relationship where air resistance (in ohm cm) = 6e18 / N where N is the number of ions. 15Kohm total resistance over 300m is just 0.5 ohm cm. So N = 1.2e19 ions. Assuming 80m across, 300m tall that is a conical volume of 5e5m^3. So the ion density would be about 2.3e14 ions per cubic metre. At the high end a storm produces 5000 ions per cubic cm or 5e9 pr cubic metre. So you have a factor of 5,000 times more ions in a tornado than a thunderstorm? Or am I totally out here.

[R.A.F.]

There are some plasma physicists on here - but I am not sure how many of them read this section of the forum.

What might be putting people off is the sheer length and 'wall of text' effect of your post.

When the OP posts that Most of what passes for proof in this world is not proof at all, then it becomes very difficult to "find" a common ground for discussion.

[CharlesChandler]

P=IV describes the electrical power of DC. You are essentially claiming that is converted to heat with 100% efficiency. P=I^2 R might be a better fit if you assume that air breaking down acts like an Ohmic resistor.

Whatever energy does not escape the system is always fully thermalized within the system (assuming that there is no way of converting it to potential in some other form). As far as I know, the only energy that escapes a tornado is a little bit of EM radiation. So it's not 100% efficient. But the difference between 100% and 90%, if there was that much difference, still wouldn't be theoretically significant. The issue is that there is a major heat source within the tornado itself. This is part of the difference between a tornado and a standard vacuum vortex. In fluid dynamics, entropy increases with distance from the source of the energy. Hence the low pressure should relax with distance from the source of the low pressure. But a current through the vortex causes resistive heating throughout the entire vortex. If the general sense of the flow field is upward, the heat accentuates the flow, and that's throughout the vortex, which is different from a simple vacuum vortex, which is getting all of its energy from one end of the system.

At the high end a storm produces 5000 ions per cubic cm or 5e9 pr cubic metre. So you have a factor of 5,000 times more ions in a tornado than a thunderstorm?

The reduction of pressure inside the tornado reduces the electrical resistance, which encourages the current. I don't know about 5,000 times more ions, but we'd expect it to be far higher than the resting ion density in a thunderstorm.

If there is a ground current would it not be possible to encourage or start (or discourage and terminate) tornado formation by suitable ground conductors forming a shorted turn?

Since the Earth is a conductor, wires on the ground wouldn't make much difference. Even pointy conductors in the vicinity of a tornado have no noticeable effect. Only massive differences in conductivity, on a big scale, affect the behavior of a tornado. For example, tornadoes "seem" to pick up strength when crossing rivers or lakes. One explanation is that the reduction in skin friction over water enables faster airflows, but I think that the increased conductivity accentuates the electrostatic forces at play. When it comes to induced charges that result in Coulomb body forces on gases, a pointy object isn't all that effective (because the "body force" is only at the point), while a huge conducting surface (e.g., from a body of water) can influence a lot more air.

When the OP posts that Most of what passes for proof in this world is not proof at all, then it becomes very difficult to "find" a common ground for discussion.

Is it not the truth? Please explain.

[R.A.F.]

Is it not the truth? Please explain.

If it is your contention that Most of what passes for proof in this world is not proof at all, then by what method do you determine what is true and what is not??

[CharlesChandler]

If it is your contention that Most of what passes for proof in this world is not proof at all, then by what method do you determine what is true and what is not??

The measure of a model is its ability to explain and predict the associated phenomena. From a pragmatic standpoint, the comprehensiveness, accuracy, and simplicity of the model determine its theoretical "cash value" (whether you're talking about predictions or postdictions).

The measure of proof is whether or not it is by definition, and only by definition. If the characteristics within the problem domain define a fully constrained solution domain (i.e., in which there is only one possible answer), such constitutes definitive proof. If you still have two possibilities, you don't have proof of either one of them, as such would be impossible. You might have a couple of darn good working hypotheses, but you don't have proof.

Usually when I say that I can provide definitive proof that tornadoes are bottleneck vortexes, and that the electric force is responsible for the bottlenecks, people ask me to cite the authority from whom I got this. And I have never successfully convinced anybody that argumentum ad verecundiam is not proof. Either you understand logic or you don't.

[profloater]

Since the Earth is a conductor, wires on the ground wouldn't make much difference. Even pointy conductors in the vicinity of a tornado have no noticeable effect. Only massive differences in conductivity, on a big scale, affect the behavior of a tornado. For example, tornadoes "seem" to pick up strength when crossing rivers or lakes. One explanation is that the reduction in skin friction over water enables faster airflows, but I think that the increased conductivity accentuates the electrostatic forces at play. When it comes to induced charges that result in Coulomb body forces on gases, a pointy object isn't all that effective (because the "body force" is only at the point), while a huge conducting surface (e.g., from a body of water) can influence a lot more air.

.

Thanksfor this but is not the water picked up a sink for energy as it evaporates releasing energy again higher in the cloud? So there is a net increase in input energy from electric flows over water?

[profloater]

If there is a ground current would it not be possible to encourage or start (or discourage and terminate) tornado formation by suitable ground conductors forming a shorted turn? What would be the effect of a great shorted turn laid on the ground under a vortex drawing a radial ground current? This would be the magnetic equivalent of a lightning conductor discharching the lower portions of a thundercloud.

[Shaula]

Well, can't really argue against a series of assertions. I would rather see a model for this producing predictions than these postdictions. I am really not convinced that all energy in a system that doesn't escape is thermalised by default.

Does your model works for waterspouts too?
Surely the water should produce some radical changes in behaviour if the tornado is electrically heated?

[CharlesChandler]

Well, can't really argue against a series of assertions.

Which assertions do you believe are unsupported?

I would rather see a model for this producing predictions than these postdictions.

I agree that explaining after-the-fact is a lot easier than predicting the outcome of future research. I can get into predictions if you want, but there will be no way for anybody to provide any sort of critical review until the data are collected. In the meantime, all that we can do is check for consistency with existing data, and suspect that if the model can't even explain data we already have, accurate predictions will probably be just dumb luck.

Just in terms of postdictions, it's nevertheless significant that this is the first truly physical model of tornadoes that identifies adequate energy sources, and accounts for the locations and forms of the energy releases. Previous physical models can be easily dismissed, and purely numeric models are not competitors in this endeavor.

The potential value of this line of reasoning is that it might greatly improve our tornado forecasting ability. Currently, meteorologists do not use EM data in their evaluation of tornado risks. My work is saying that if the EM factors are not present, a tornado will not form. This might explain why 27% of all tornadoes strike without warning, and 77% of the warnings are false alarms. Meteorologists aren't looking at the essential ingredients -- they're looking at indirect side-effects, and that's why they're getting so many false positives and negatives.

Does your model work for waterspouts too?

Yes.

Not all theorists consider waterspouts to be the same breed of vortex. The standard model asserts that tornadoes are just extensions of the rotation within the cloud (i.e., the "mesocyclone"). But 20% of the vortexes reported as tornadoes were associated with storms that did not have any significant rotation. These are called waterspouts, or "landspouts" if they occur over land, and people sticking to the standard model dismiss these as some other type of vortex, that cannot be predicted with existing technology (i.e., Doppler radar looking for rotation inside the cloud), and therefore should not be allowed to muddle the theoretical treatment of the topic.

To me, that's data collection driving theory, which is always a mistake. The physics problem is the same. There has to be a heat source within the vortex, or the air would never get hoisted > 1 km inside the vortex. In the atmosphere, at this scale, updrafts (and downdrafts for that matter) can only happen if there has been a heat exchange. Vortexes that occur in the absence of rotation in the cloud, and even while the primary updraft in the storm is weakening, are not "some other type of vortex" that shouldn't confuse us. Rather, our inability to accurately predict tornadoes should confuse us, and vortexes occurring when the fluid dynamic factors are weak should tell us to pay more attention to non-fluid dynamic forces (i.e., EM).

[tusenfem]

Unfortunatly, I am too busy with refereeing and writing papers, preparing talks and posters for several meetings and helping my student, so I have no time to get into this at the moment.

[CharlesChandler]

tusenfem, thanks just for taking the time to decline. Your criticisms 4 years ago surely saved me an untold amount of time, and I wouldn't be where I am now without your help then. Please know that I appreciate it. Cheers!

[chrlzs]

This may be a ludicrously simplistic set of questions (never stopped me before..), but there seems to be some implication that the bottleneck shape (and the fact it goes down and not up?) is somehow unexplained by current theories, or better explained by this theory, yes?

In that case, can you please supply:

1. Some checkable maths, numbers, dimensions, calculations, predictions.. showing your theory in action, or at the very least, explain how it can be tested/verified/falsified.

2. Is the bottleneck effect in waterspouts, and in a body of any fluid (eg in my bathtub or coffee mug) that is whirlpooling into a similar vortex, in some way fundamentally different, or is your suggestion applicable to those too? I see you have 'answered' the first with a vague handwave, but how about the second?

I'm not a meteorologist and so I'm way out of my depth and probably wrong.. but I have to say I didn't even agree with your very first phrase:

The defining characteristic of a tornadic vortex is that the tightest radius is on the ground..

That's THE defining characteristic? Or just one characteristic you are interested in..

BTW, I'm finding the wall-of-text to be a problem too, and while again i admit my depth of knowledge is lacking, I can't help thinking there are a truckload of unexplained assumptions and unsupported assertions being made, plus some examples where you use your own unsupported hypothesis as a base to build further hypotheses, eg:

We have already acknowledged that the tornadic inflow is charged, and that this somehow results in the constriction of the radius at the ground..

Who is the we that acknowledged this?

And the following phrases made me cringe...!

The proof that the electric force is responsible is that it is the only possibility...
Most of what passes for proof in this world is not proof at all. But this actually is proof, because it's by definition, wherein all other possibilities have been eliminated... {er.. say what?}
No more criticisms??? Whaaaaaa...
..and I guess now I pass the test... {yes, that one had a smilie, but even so...}
I'll criticize myself if that's the only way to make progress... {This after just two days at a forum focused on astronomy, NOT meteorology???}
There is only one possible answer to that question... {O Rly?}
Now, if we're done here, I'll start preparing the OP for a new thread... {See above - after two days??}
That's why I'm here, instead of on a meteorological board, because it's totally outside of their field of focus...
Previous physical models can be easily dismissed...
Either you understand logic or you don't...

I'm afraid stuff like that leaves me cold..

[CharlesChandler]

I'm finding the wall-of-text to be a problem too...

Ah, but then should I answer your questions, having already answered them in previous posts, and be further criticized for being too verbose?

BTW, in previous threads, it didn't take two days for me to get flooded with criticisms -- it took only two hours.

[R.A.F.]

The measure of a model is its ability to explain and predict the associated phenomena. From a pragmatic standpoint, the comprehensiveness, accuracy, and simplicity of the model determine its theoretical "cash value" (whether you're talking about predictions or postdictions).

The measure of proof is whether or not it is by definition, and only by definition. If the characteristics within the problem domain define a fully constrained solution domain (i.e., in which there is only one possible answer), such constitutes definitive proof. If you still have two possibilities, you don't have proof of either one of them, as such would be impossible. You might have a couple of darn good working hypotheses, but you don't have proof.

Usually when I say that I can provide definitive proof that tornadoes are bottleneck vortexes, and that the electric force is responsible for the bottlenecks, people ask me to cite the authority from whom I got this. And I have never successfully convinced anybody that argumentum ad verecundiam is not proof. Either you understand logic or you don't.

You failed to mention by what method you are able to determine true from untrue....which is what my question actually was.


...but that's "ok"....since I don't understand logic, I won't be posting to this thread...

[Shaula]

It is not about numbers of words (although to be fair you could easily cut them down and present points in a crisper way). It is about presentation. I'm bad at being concise myself and over the years have had to learn to draft things two or three times, cutting down the words and refining the structure each time. It has really helped when writing reports and papers.

You only give current values for a tornado - does the current play any effect in tornado genesis? Or are you only proposing it sustains a tornado (your comments in #20 seem to imply otherwise)?

I would expect to see you go about showing your model works in the complete opposite way to the way you have done it if you do think EM forces are important in the creatoin of a tornado. First you show how the current flows form and when they should/should not form. Then you work out the effects of this. Then you show how these effects naturally lead to a tornado, giving assumptions, calculations and mechanisms for all steps. You do not start with the phenomenon you want to describe, say what you think it looks like and then fit your ideas to it via a series of wordy explanations.

And as I said before you need to give equations in a far better way than you have. State what each term means, rather than just give them in terms of units. Equations are intrinsically linked to what they describe, not just their units.

[CharlesChandler]

You only give current values for a tornado - does the current play any effect in tornado genesis? Or are you only proposing it sustains a tornado (your comments in #20 seem to imply otherwise)?

I'm saying that the neutralization of the space charge in the air just above the ground is the prime mover, which is responsible for spawning and sustaining the tornado. This neutralization can occur due to an electric current down from the cloud, through the reduced resistance inside the vortex, or it can come up from the ground, in the form of charged particles that are lofted into the charged air by the electric force. Either way, the charged air at the ground is the essential ingredient, without which there would not be a tornado.

As concerns your other comments about my general approach, I "think" that I understand what you're saying. And I certainly appreciate your helpful tone. The problem with the step-by-step, bottom-up approach is that I can't seem to get people to part with their pre-formed conclusions. Everybody thinks that tornadoes are already well-described in purely fluid dynamic terms. Hence I can identify all of the necessary forces, and cite all of the available data in support of my contentions. But people are convinced that I'm solving a non-problem, and that somewhere in there, I must have slipped a decimal point. This is why I decided to directly confront the failure of fluid dynamic principles in accounting for the power of a tornado. In an open system, a bottleneck vortex just isn't possible, and tornadoes are definitely bottleneck vortexes. If I can't get people to acknowledge that, there's no point in going any further. Give me some time to try to figure out how to present this in a more straight-forward way, that would also separate people from their false assumptions.

Is not the water picked up a sink for energy as it evaporates releasing energy again higher in the cloud? So there is a net increase in input energy from electric flows over water?

Water is picked up, and it does evaporate, releasing its energy (via condensation) higher in the tornado. But there's no net increase in energy. First the water in a heat sink, then it's a heat source. The charge recombination, between the positive air and the negative water, releases heat, which helps with the evaporation. Evidence of this heat source at the base of the waterspout is commonplace. Notice that in the following images, there isn't any condensation at the bottom of the vortexes. This is interesting because that's where the pressure is the lowest. If water vapor doesn't condense there, it shouldn't condense anywhere in the vortex. But it does condense, within the first 100 m of its ascent, once the heat has been distributed amongst the other molecules, and the water vapor is cool enough to condense.

Waterspout near Oran, Algeria, 2007-10-30, courtesy Nassimatique.

Waterspout off the coast of Brach, Croatia, 2006-08-04, courtesy D. J. Malden.

Line of waterspouts off the coast of Albania, 1999-08-01, courtesy Roberto Giudici.

[CharlesChandler]

Oh and there's one other problem with attempting a bottom-up explanation of this theory that I forgot to mention. The foundational piece is that the air flowing into the tornado is charged. Well, this "fact" was inferred rather than observed. To my knowledge, nobody has ever done a space charge study of the tornadic inflow. So I don't have that fact, which I can then piece together with other facts to put together the puzzle.

There is plenty of indirect evidence. For example, in the previous post I included photography of waterspouts showing an absence of condensation at the bases of the vortexes. This is anomalous because that's where the pressure is the lowest, and therefore, that's where we'd expect condensation, if anywhere in the system. One possible reason for the absence of condensation is the release of heat from charge recombination, which would get the air above its dew point, as mentioned previously. But if you think about it, there has to be more to it than that, because there is also a major heat sink, in the evaporation of aerosols lofted into the vortex. The Joule heating from charge recombination should be small compared to evaporative cooling. The other possibility is that the air is still charged, and the Coulomb force is preventing ions from condensing. If that's the case, it makes sense that the water vapor then condenses higher in the vortex, assuming that there is a neutralizing current inside the vortex. The neutralization removes the Coulomb force that was preventing condensation. Hence asserting that the air is charged enables a physical explanation of this phenomenon.

And I can demonstrate that the problem domain is full of such phenomena, all of which make no sense unless we consider the possibility that the tornadic inflow is charged. Then everything makes sense. Furthermore, I can demonstrate that charged inflow is the only piece capable of making sense of all of it, as I can rule out all other possibilities in the analysis. Latent heating doesn't adequately explain tornadoes, not does a sustained cloud-to-ground electrostatic discharge, nor do any of the other physical possibilities. So I can prove that this inference is correct.

What I cannot figure out how to do is present this as a simple derivative work, where I take a collection of previous works, and show that something new can be constructed of them, without having to do any inductive reasoning. And if I write it as a "what if" paper, presenting the hypothesis that the tornadic inflow is charged, and then working out the implications, I first have to convince people that there is a need for "what-if's" in this topic. I can't even figure out how to do that.

Any suggestions?