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Author Topic: Can a jet engine pointed skyward avert global warming?  (Read 3173 times)

Offline cheryl j

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(I had no idea what to title this)
I watched a  environmental documentary tonight called "Elemental." One of the people in the documentary was a man who claimed that a jet engines pointed toward the sky could actually create thermal air currents that would break up the layer of greenhouse gases that are blocking the escape of much of Earth's heat. He says this will at least slow down global warming and buy us some time. According to Harmon, one device, ten feet in diameter "can affect a very large area up to 20,000-25,000 feet high and 20 miles in diameter."

Is there any way something like this would work?

 
« Last Edit: 27/11/2013 22:54:08 by chris »


 

Offline alancalverd

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Re: Jay Harmon's invention
« Reply #1 on: 25/11/2013 08:31:29 »
People have been pointing jet engines in various directions for about 70 years, with no measurable effect on anything.

Thunderclouds are formed by natural thermal vortices that can extend up to 50,000 ft and a good cold front (such as passes over the UK every week) delivers as much energy as several atomic bombs. Adding a puny jet engine will just make you feel even more insignificant.

And the people who peddle greenhouse scare stories will tell you that the greenhouse bogey gas is intimately mixed and distributed throughoput the atmosphere, not confined to a layer.   
 

Offline CliffordK

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Re: Jay Harmon's invention
« Reply #2 on: 25/11/2013 09:06:02 »
Here is a summary of Jay Harman's idea.

So, the idea is to create an artificial tornado to "mix" the warm lower atmosphere with the cool upper atmosphere.  And, it might be effective by actually increasing the heat flux away from the planet. 

I assume the article says to use a jet engine, but perhaps one would better consider a very large turbine engine such as a helicopter uses.  Then drive a monster Lily Impeller. 

I agree, however, with alancalverd that the energy to produce a tornado would be extreme.  Some of the energy might come from the natural updraft of warm air, but still, it wouldn't be easy to maintain a stable tornado. 

And, as the article mentioned, one may not truly wish to actually produce tornadoes near a populated region even if it was possible. 

The other thing is that if CO2 is truly the problem, would one wish to add another engine burning the equivalent fuel of a A380 or Boeing 787?

As far as putting the vortex in the Himalayas.  The glaciers are maintained by the high altitude cooler air.  It may be effective to mix high altitude air with even higher altitude (which, of course, is very thin).  However, mixing valley air with the mountain peak air could accelerate the glacier melting.

It is an idea to try to augment evaporation with the goal of increasing rainfall in arid regions.
 

Offline Bored chemist

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Re: Jay Harmon's invention
« Reply #3 on: 25/11/2013 11:06:48 »
"According to Harmon, one device, ten feet in diameter 'can affect a very large area up to 20,000-25,000 feet high and 20 miles in diameter'."
20 miles in diameter is 10 miles in radius that's about 16,000 metres
pi r squared gives 800 million square metres or so of area.
Each square metre picks up something like 1KW from the sun, so that's a solar energy input of roughly a million megawatts.
This jet engine is going to make how big a difference to that?

 

Offline distimpson

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Re: Jay Harmon's invention
« Reply #4 on: 25/11/2013 18:21:24 »
(I had no idea what to title this)
I watched a  environmental documentary tonight called "Elemental." One of the people in the documentary was a man who claimed that a jet engines pointed toward the sky could actually create thermal air currents that would break up the layer of greenhouse gases that are blocking the escape of much of Earth's heat. He says this will at least slow down global warming and buy us some time. According to Harmon, one device, ten feet in diameter "can affect a very large area up to 20,000-25,000 feet high and 20 miles in diameter."

Is there any way something like this would work?

The key word is "affect", could mean substantial or very little. I would think the folks at NCAR with their atmospheric models could answer the questions, how large a fan would give what effect.

Here is a link to his company  http://paxscientific.com/. He could be a sincere fellow with an idea to save the world but I do not know any corporations that would invest in that.  Could go for direct crowd sourcing but I'd be pitching to one of the ultra rich, google, facebook, amazon, ..., founders as they have already done the work (of crowd sourcing that is).

Disclaimer, I do not have any direct knowledge of this fellow, his company or his efforts and do not know if the concepts are sound or not. My response is provided for entertainment purposes only.

 

Offline CliffordK

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Re: Jay Harmon's invention
« Reply #5 on: 25/11/2013 19:12:50 »
Each square metre picks up something like 1KW from the sun, so that's a solar energy input of roughly a million megawatts.
This jet engine is going to make how big a difference to that?
The watts may be irrelevant as the goal is to send warm lower atmosphere air upward, and bring cool upper atmosphere air downward.  I.E "Mixing".  With the radiation of heat in the upper atmosphere taking a shorter path to radiate into space. 

Still, it would be an ambitious project to make an artificial vortex, say 10,000 feet tall, and augmenting the atmospheric mixing over several square miles of area.

If successful, perhaps it might be able to reduce the likelihood of tornadoes by homogenizing the atmosphere, assuming it could hold the cyclones in one place and didn't loose them.

I would think he should be able to at least make some artificial dust devils to study his vortices in air rather than water or on a computer.
 

Offline alancalverd

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Re: Jay Harmon's invention
« Reply #6 on: 25/11/2013 19:28:20 »
No problem doing it. And no point.

(a) When the atmospheric conditions  are suitable for the production of a stable vortex, it happens anyway. That's how cumulus clouds - and tornadoes - are formed. If the lapse rate won't sustain a vortex, there's no point in trying to start one. 

(b) The atmosphere is already homogeneously chemically mixed thanks to convection and geostrophic wind.

(c) There is nothing chemically inhomogeneous about tornadoes. Adding a few more at point A won't prevent them forming at point B. 

(d) Hundreds of jet aircraft take off and land all over the world every day. Their wingtip vortices persist for a few minutes and have damn-all effect on the rest of the atmosphere. Their engine vortices persist for a few seconds and have even less effect. In really unstable conditions you can nucleate a bit of fog, but it's inconsequential to anyone except the next plane in the landing sequence.

(e) pointing a stationary jet exhaust upwards  is a lot of fun until the vortex gets sucked back into the intake, at which point the intake temperature rises and all hell breaks loose.
 

Offline CliffordK

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Re: Jay Harmon's invention
« Reply #7 on: 25/11/2013 20:20:10 »
If you could mix the hot low altitude air and cold upper atmosphere air, (or is it a high/low pressure?), anyway, it might help dissipate or prevent tornadoes. 

I don't think the idea is to use an unmodified jet engine, but rather using a turbine powered  Lily Impeller which may be quite different. 

Jets do, of course, add moisture to the upper atmosphere, and may affect the climate due to the upper atmosphere moisture.  A ground based device wouldn't do that, at least not in the same way.

The required power does seem to be high.
 

Offline JP

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Re: Jay Harmon's invention
« Reply #8 on: 25/11/2013 20:52:10 »
Skepticism is good here.  I note that in the site you linked, Clifford, there are also stories which take the "water has memory" idea seriously and claim that if you put a flower in water, images of water droplets all look like the species of flower you used.  I'm not going to dignify that "research" with a link.  :)  Science stories posted on sites with dubious scientific credibility without any peer-reviewed publications to back them up are hard to take seriously, and the claim that using a fancy new turbine would allow us to spin stable vortices in the atmosphere that extend up 10,000 feet is a pretty extraordinary claim. 

The energy contained in the vortex alone (since it would have to be fairly wide and fast to be stable in real atmospheric conditions) would have to be huge, and the process of generating and sustaining it would be hugely inefficient.  A back of the envelope calculation shows that a single vortex of 100 meters in width rotating once per minute would have about 1/1000th of the energy of an atomic bomb.  It would also probably not be big enough or fast enough to be stable.  At one mile wide and rotating once every 3 minutes (an outer wind speed of 55 mph), your vortex would have an energy equivalent to the largest nuclear weapon ever set off.  As Alan pointed out, to be significant, and given losses in generating these things, you'd be using a significant fraction of the world's total energy output in a given year to do this...

Though it does point out how insignificant out energy output is compared to even a single large storm.
« Last Edit: 25/11/2013 21:02:37 by JP »
 

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Re: Jay Harmon's invention
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