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Can we prevent tornadoes?

by SpaceGuy50
Tags: prevent, tornadoes
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Dotini
#55
Jun1-11, 07:59 PM
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http://abcnews.go.com/WNT/video/torn...river-13737392

Here is a video, taken on cue for you just minutes ago, of a tornado crossing a major river at Springfield, Mass.

Respectfully submitted,
Steve
Evo
#56
Jun1-11, 08:07 PM
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Quote Quote by DaveC426913 View Post
In refuting artist's claim that dumping water into a torando would weaken it, you pointed out that "...tornadoes form from severe rain storms and hurricanes...". While you didn't say explicitly that tornadoes get their strength from moisture, it seemed to be the implication - the significance of the comment - to this reader (and thus possibly others). So I went to see if I could bolster the notion (after all that is how hurricanes get their power). But I haven't been able to find a reference either way.
Just remember, if I don't say something, it's because I didn't say it, for a reason. So please refrain from guessing what I might have said or might have meant. You can always ask "did you mean to say *this* and forget?, and I'll say *no*.

What causes tornadoes?
Thunderstorms develop in warm, moist air in advance of eastward-moving cold fronts
But that doesn't mean that these conditions always create tornadoes. All I asked was for him to back up what he said. He refused.

http://www.nssl.noaa.gov/edu/safety/tornadoguide.html

Since he's reading the global rules now. Here's the earth forum rules for artist.

Earth Sciences Posting Policy

Controversial claims must be supported by evidence that comes from a scientific, peer-reviewed journal or a similarly reliable source, i.e., unsubstantiated claims are not allowed.
Evo
#57
Jun1-11, 08:21 PM
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Quote Quote by Dotini View Post
http://abcnews.go.com/WNT/video/torn...river-13737392

Here is a video, taken on cue for you just minutes ago, of a tornado crossing a major river at Springfield, Mass.

Respectfully submitted,
Steve
Wow, amazing.
cph
#58
Jun1-11, 11:09 PM
P: 45
Might larger cities statistically be more protected because of a heat shield effect? Perhaps the heat of a city is distruptive, in that if more heat (energy) is added to the atmosphere, then perhaps less exothermic water droplet formation.
Ophiolite
#59
Jun2-11, 11:51 AM
P: 288
This 2010 paper appears to contradict artists claim. The detailed maths are rather dense, but if I am interpreting it correctly, water would enhance rather than detract from the energy of the tornado.
Dotini
#60
Jun2-11, 12:03 PM
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http://www.rawstory.com/rawreplay/20...funnel-clouds/

This is excellent video of the business-end of a Springfield 6/1/11 tornadic vortex just as it attaches itself to the surface. Without this critical leech-like attachment, tornadoes would be only a minor nuisance. Wouldn't learning how to prevent, reverse or destroy this one feature solve our problem?

Respectfully submitted,
Steve
Evo
#61
Jun2-11, 01:25 PM
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Quote Quote by cph View Post
Might larger cities statistically be more protected because of a heat shield effect? Perhaps the heat of a city is distruptive, in that if more heat (energy) is added to the atmosphere, then perhaps less exothermic water droplet formation.
I've actually read that more heat causes more tornadoes, but this was in a discussion of AGW, so you will need to do your own research on that.

Here is a reason we do not see many tornadoes in a major downtown area.

Why does it seem like tornadoes avoid downtowns of major cities? Simply, downtowns cover such tiny land areas relative to the entire nation. The chance of any particular tornado hitting a major downtown is quite low--not for any meteorological reason, but simply because downtowns are small targets. Even when tornadoes hit metro areas; their odds of hitting downtown are small out of space considerations alone. For example, downtown Dallas (inside the freeway loop) covers roughly three square miles, Dallas County, about 900 square miles. For a brief tornado in Dallas County, its odds of hitting downtown are only about 1 in 300. Still, downtown tornadoes have happened, including at least four hits on St. Louis alone. The idea of large buildings destroying or preventing a tornado is pure myth. Even the largest skyscrapers pale in size and volume when compared to the total circulation of a big tornado from ground through thunderhead.
http://www.spc.noaa.gov/faq/tornado/
Evo
#62
Jun2-11, 01:26 PM
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Although this from the two tornado links I posted previously.

Are there electromagnetic or magnetohydrodynamic explanations for the development of tornadoes?

As far as scientists understand, tornadoes are formed and sustained by a purely thermodynamic process. As a result, their research efforts are towards that end. They have spent a lot of time modeling the formation of a tornado and measuring many parameters in and around a tornado when it is forming and going through its life cycle. They have not seen any evidence to support magnetism or electricity playing a role.
http://www.nssl.noaa.gov/faq/faq_tor.php
Dotini
#63
Jul21-11, 07:17 PM
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Quote Quote by Evo View Post
Although this from the two tornado links I posted previously.
I was unable to locate the statement regarding "tornadoes being formed and sustained by purely thermodynamic processes" in the NOAA FAQ. Perhaps it has been deleted?

Anyway, I thought readers, particularly Chas Chandler, would be intrigued by this:

http://www.jstor.org/pss/1723338

Electric Currents Accompanying Tornado Activity

Abstract
Measurements of the magnetic field and earth current in the vicinity of a tornado show large step-like deflections coincident with the touching down of the funnel. Calculations with a simple current model indicate that a minimum current of several hundred amperes must be postulated to account for the observed deflection in magnetic field. The existence of a steady current of 225 amperes for a period of about 10 minutes provides joule heat at the rate of approximately 10$^{10}$ joules per second, and involves a total charge transfer of 135,000 coulombs. The calculations imply that a tornado is electrically equivalent to several hundred isolated thunderstorm cells active simultaneously.


Respectfully submitted,
Steve
ChasChandler
#64
Jul24-11, 09:22 PM
P: 13
Quote Quote by Dotini View Post
Do such multiple vortexes feed only a single cyclonic cell, or do they each have their own? Such organization and complexity is really impressive.
Hey Steve,
I have never seen any evidence of there being more than one mesocyclone (the large, rotating updraft) inside a supercell. The mesocyclone typically has a diameter of something like 2 km, which is the diameter of a very large tornado. While there can be tornadoes anywhere in the vicinity (sometimes several km away), to my knowledge the main tornado is always associated with the mesocyclone.

Quote Quote by DaveC426913 View Post
In refuting artist's claim that dumping water into a tornado would weaken it, you pointed out that "...tornadoes form from severe rain storms and hurricanes...". While you didn't say explicitly that tornadoes get strength from moisture, it seemed to be the implication - the significance of the comment - to this reader (and thus possibly others). So I went to see if I could bolster the notion (after all that is how hurricanes get their power). But I haven't been able to find a reference either way.
Here are some rough calculations that I did, using numbers from the source that Steve quoted, as well as other sources. Tornadoes do seem to get a respectable amount of energy from the release of latent heat from the condensation of water vapor, while ohmic heating from the electric current inside the tornado appears to make a far more substantial contribution.

First the latent heat calculations. Let's assume that the ambient temperature is a sweltering 40 C, and that the relative humidity is 100%. The lowest pressure drop ever recorded in a tornado was 100 mb below ambient. That would lower the temperature to roughly 10 C, forcing the condensation of most of the water vapor, and the release of latent heat.
maximum water vapor content at 40 C = 51.1 g/m3

maximum water vapor content at 10 C = 9.4 g/m3

condensation = 51.1 − 9.4 = 41.7 g/m3

tornadic inflow (EF1) = 1,000 m3/s

total condensation = 1,000 m3/s 41.7 g/m3 = 41,700 g/s

latent heat from condensation of water = 2,257 J/g

total latent heat = 41,700 g/s 2,257 J/g = 94,117,000 J/s

watt = joule / second

power = 94,117,000 W
Now the ohmic heating calculations. The magnetic field generated by a tornado was measured at 1.5  10−8 teslas from a distance of 9.6 km away using a magnetometer. From this we can calculate the amps.
amps = teslas 2 π r / permeability

permeability of air = 4 π  10−7 N/A2

amps = (1.5  10−8 2 3.14 9600) / (4 3.14 10−7) = 720 A
Guessing that the tornado was 300 m tall, and given an electric field of 5 kV/m, we can then calculate the watts.
volts = 300 m 5,000 V/m = 1,500,000 V

watts = amps volts = 720 1,500,000 = 1,080,000,000 W
More conservative estimates of the typical current densities are in the range of 100~250 amps, but even at the resultant 150~375 million watts, that's still a lot more power than the 100 million watts that could be coming from latent heating.

In addition to the ohmic and the latent heating inside the tornado, there is also, of course, the low pressure aloft inside the thunderstorm enhancing the updraft, and there is also frictional heating at the lower boundary.

Only the frictional heating at the ground level could possibly be responsible for the extreme low pressure at the base of the tornado, as it is the only energy source that is concentrated near the ground. Estimates of the (destructive) work done by the tornado on the ground are in the range of 5 million watts for an F1 tornado, to 5 billion watts for an F5. The effect on the air of the thermalized energy is, of course, to increase its buoyancy, accounting for the vigorous updraft at the base of the vortex, which cannot be explained in any other way.

Quote Quote by Dotini View Post
I was unable to locate the statement regarding "tornadoes being formed and sustained by purely thermodynamic processes" in the NOAA FAQ. Perhaps it has been deleted?
Here is the link. The quote is in a pop-up that appears if you hover over the question in the right-hand sidebar, "Are there electromagnetic or magnetohydrodynamic explanations for the development of tornadoes?"

TORNADO FAQs
anonymity
#65
Aug10-11, 12:34 AM
P: 163
Quote Quote by Borek View Post
I think it is possible - you have to find (and kill) correct butterfly in time.
lol @ chaos theory jokes =s
ak666666
#66
Aug11-11, 03:23 AM
P: 1
With much more greenery, IR would be reflected back more, ground will heat up less and hot air will rise up less. This could lessen tornado force. No?
DoggerDan
#67
Aug13-11, 08:54 PM
P: 77
Quote Quote by Ivan Seeking View Post
While weather experts understand what conditions tend to produce tornadoes, I think there is a good bit not understood about exactly when, where, and why they occur. Until we have a better understanding, it would seem that prevention is a little ahead of the game. Beyond that, there are such tremendous amounts of energy involved that one wonders if intervention could ever be practical. For the foreseeable future, increasingly effective early warning systems are probably the best hope.
Some dwellings are far more tornado-resistant than others. If I ever moved to Kansas, I wouldn't life in a traditional two-story house!
atheerzahroon
#68
Aug27-11, 09:39 AM
P: 3
I think if we can make a thermodynanic changes to the maximum or minimum pressure regions of tornado we can control it. Is there a pressure diagram of these regions ?
atheerzahroon
#69
Aug27-11, 09:57 AM
P: 3
Here are some rough calculations that I did, using numbers from the source that Steve quoted, as well as other sources. Tornadoes do seem to get a respectable amount of energy from the release of latent heat from the condensation of water vapor, while ohmic heating from the electric current inside the tornado appears to make a far more substantial contribution.




This is a very good calculations. But dont you think that making such big magnetic field is hard to reach and you need to direct your magnetic effects to the tornado. How can you do the by using a wide spread magnetic field.
atheerzahroon
#70
Aug27-11, 10:08 AM
P: 3
how is that
DoggerDan
#71
Sep9-11, 06:56 PM
P: 77
It appears you're saying the best counter against a tornado is to cool it, or at least the air feeding it. Since it's usually heavily laden with moisture, an aerosol of water wouldn't be very effective.

Obviously, the application of heat would simply strength it, right? If so, detonating a nuke would only add energy to the system, although it may can enough disruption to stop one.

I doubt that, though.

The electric perspective might have merit, but again, I doubt we could afford to generate any sort of counter-current of that magnitude. Tornadoes much generate/use massive amounts of energy. What would it take? The output of the entire Eastern Seaboard?
joema
#72
Sep22-11, 04:04 PM
P: 101
It appears progress in radar and computers might effectively accomplish the same goal as tornado prevention, at least to some degree. If you could predict with extreme accuracy and lead time when a tornado happened, this would reduce the need to prevent it (which might not be possible, anyway).

A big limitation to current tornado warnings is the slow 5 minute update cycle on the WSR-88D doppler system. This limits warning time, plus limits data needed for vortex signature analysis.

Currently tornado warnings are issued only on visual sightings or radar-indicated features combined with human analysis. There's a fairly high false detection rate. You normally want more than a single radar frame before calling a warning, which would take 10 minutes for two frames. A rapidly developing storm can slip between such slow updates.

Phase array radar (like used on Navy Aegis ships) could increase the update rate to 60 sec for a total volume coverage pattern, maybe faster. In weather reflection tests, the Navy Aegis SPY-1 radar already exceeds the temporal and angular resolution of the NexRad WSR-88D, despite the latter using 750,000 watts output. See graphic.

The National Weather Service has a single phased array weather radar test installation, called MPAR (Multi-mission Phased Array Radar). The optimum scan pattern is still being researched. Also, because the beam is electronically (not mechanically) steered, a severe storm region could be selectively painted every few seconds without sacrificing less-frequent 360 deg. coverage. This could increase the update rate for a given storm cell by a factor of 50 over the current WSR-88D system.

If MPAR is ever funded and deployed nationwide, the additional data from the high update rate could be combined with new computer models to issue high-confidence warnings much further in advance. At least that's the theory. The goal is "warn on forecast", vs the current "warn when tornado is detected".

If that happens and the lead time, accuracy and confidence level of tornado warnings greatly improve, people can just get out of the way.

http://celebrating200years.noaa.gov/...ome.html#intro

http://www.nssl.noaa.gov/research/radar/mpar.php

http://www.nssl.noaa.gov/research/forewarn/

http://www.youtube.com/watch?v=R6Nrc...eature=related
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SPY1VsNexRad.JPG  


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