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Preempting Hailstone Formation To Protect Cars
Makarand writes "Nissan has become the first automaker in the United States to start using
a device that suppresses hail formation to protect its fleet of new vehicles
from hailstorm damage. The device is a cannon capable of shooting sonic waves upto
50,000 feet in the air to keep hailstones from forming. The
device comes with its own weather radar and activates when it detects
conditions favorable for hail formation. The device can provide
hailstorm protection in an area with one-mile radius by firing
sonic waves every five seconds."
Now they just need sharks with frikkin' radar beams.
I have bad karma....
Open source is heavenly, Microsoft is the devil, SCO is going to hell
These fine people from "ke-bek"
Sponge!
...instead of having hail fall on your car, 747s do.
This is common practice around my area (Christchurch, New Zealand) to protect pip fruit and grape crops from hail damage. I'm frankly surprised this is news.
was known as a roof.
Customer Rep. Exec: Apparently consumers are complaining about hail damage to their cars.
CEO: Hail damage?
Head Engineer: Great, just great. The biggest problem that people want to complain about, we have no solution for. Hell, we were never even told that this was a problem!
CEO: Ok, ok. Look, we have to think. Does anybody have an idea as to how we handle this?
Guile: Sonic boom!
And so, Col. Guile's post-Street Fighter career, previously up in the air, was solidified.
Until Slashdot fixes the funny modifier, use insightful or interesting. The poster knows your intentions.
Apparently you don't want to live nearby (see the bottom of the story).
This sounds like it's worse than living next to an airport.
Related:
r ology/Weather_Modification/
. php
http://dir.yahoo.com/Science/Earth_Sciences/Meteo
http://www.weathermod.com/projects/hail/argentina
http://www.ametsoc.org/policy/wxmod.html
Any idea what the environmental impact is from these things?
What's that you say? I can't hear you!
First reading of the article gave the impression that Nissan's new cars would be equipped with some kind of sound raygun which could be used for far more interesting things than blocking hailstones. Hey, aim that raygun at Ms Jone's house, watch the windows shatter. Cops coming? A little blast of decibels and their cars explode. Not to mention their eardrums and maybe even heads. Ugh.
But no, we're not going to see commercialized versions of the famous Somalian 'technicals', pick-ups with anti-aircraft guns mounted in the back.
Instead it's some kind of 'Highlander 2' plot in which giant rays are going to be beamed into the sky in order to prevent catastrophe raining down.
So, I have three questions.
(a) does anyone actually believe it's possible to stop hailstones forming in the heart of giant thunderclouds whose energies are hugely more than anything we can produce.
(b) what happened to the 'roof'? A simple, yet efficient way of stopping hailstones.
(c) who sold Nissan this thing? I'm looking for a good salesman for my company.
Ceci n'est pas une signature
That said, I'm really curious if it even works.
Of course it works!! Here's a little fun with science you can make yourself that proves how this works.
What you need:
1 peice of paper.
1 speaker, connected to a stereo.
some music.
Start by ripping the paper into little shreds and balling them up into tiny little balls. Next, take all the little balls and mash them together into one big ball.
Now if you have decent speakers you can just set the paperball mass on top of the cabinet. For those wussy computer speakers, I recomend turning it on it's side and placing the ball directly in the cone.
Now crank up your volume and watch what happens to those little balls. They start dancing around and the bigger ball falls apart! See! Now imagine that on a smaller scale, say ice crystal size. That is exactly what is happening to the hail when it gets sonically blasted.
These guys have seriously been had. Anyone that knows anything about atmospheric physics can tell you that most atmospheric models neglect sound waves, and for a very good reason--because they are insignificant when compared with other phenomena present in the atmosphere, such as...surprise...wind. Anything on the scale of a severe thunderstorm strong enough to produce golf-ball sized hail or larger will have vertical air motions in excess of 40-50 m/s (100mph). Combine this with the tremendous amount of turbulence associated with such violent vertical motions, and a few piddly sound waves don't stand a chance.
Furthermore, hailstones of the size they're concerned with usually form miles from the location they actually fall in, and are held aloft for substantial periods of time--sometimes longer than an hour. Eventually, however, the updraft in the storm will weaken or reposition itself, and when it does, look out below. So even assuming this device could prevent hail from forming within a 1-mile radius of itself, your stuff is still gonna get the crap beat out of it anyway.
Whether the guy that sold them on this was a meteorologist or not, this sort of crockery is what gives meteorologists a bad name.
Well, if thats 120 db of any Britney song, its bound to have the hail running for the hills.
"And that solves the mystery of the missing ring" - Bender
... drive nearby sandworms to a frenzy and provoke them to attack the vehicle, swallowing it whole?
...I am proof that intelligent beings are not always intelligent...
Back in the 1970's I was able to buy a hail damaged new Falcon for $750. Ford was dumping them because the cost to repair the damage would be more than the car was worth. I thought it was a super deal.
It had dozens of quarter sized dimples, and ran really fast. I'm not sure, but it might have benefited from some kind of golf ball wind resistance effect.
Hailstones form inside the thundercloud, and grow larger as they are suspended by the thunderstorm's updraft or recycled through it. Clear ice in a hailstone corresponds to growth in warmer regions of the cloud where the water has time to flow before freezing, cloudy ice corresponds to ice formation in colder regions of the cloud where the water freezes on contact.
Hail forms when a raindrop freezes inside a cloud, but shoots back up (due to massive updrafts), and falls back down, gaining more layers of frozen rain/ice. It continues this cycle until the ball of ice is too heavy to be lifted by the updrafts, at which point it falls to the ground as hail.
Ah, but unlike 'good ions', cation has a proper scientific meaning. Cations are simply positively charged ions. As they're charged they're fairly easy to direct using magnetic fields and *waves hands* what-not. An example is a helium nucleus, which has a charge of +2, also known as alpha-radiation. So, some smoke detectors work by 'shooting cations' across a small gap.
Of course, the problem with this is that alpha-radiation is stopped by a few centimetres of air, and larger particles are probably even less effective. I've no idea if they actually 'shoot cations' thousands of feet into the air or not - it seems more likely that a large charge would propagate through the air, without any individual particle travelling very far, if they could produce enough of a potential difference.
I wouldn't say it's baloney but it does sound somewhat exaggerated.
I say we take-off and slashdot the site from orbit... it's the only way to be sure
This is funny.
In the book 'the skunk works', one of the pilots in the stealth fighters in the first Bush gulf war describes how before the war began they used to go to their hangars in the morning and find the planes surrounded by dead bats.
There were a lot of bats in the area, and the design of the fighters meant they not only didnt reflect radar, they didnt reflect sound. So these bats would be swooping around what sounded like an empty hangar, when suddenly they'd run into an invisible force field that would injure or kill them...
Yeah, that web site looks pretty sketchy to me, not that I'm an expert. The photo you mentioned has a white area in the foreground---could be snow, could be hail---and a HUGE non-white area in the background. That is NOT a picture of a "small hail-free patch", surrounded by an area with hail. There is no hail or snow visible on the far side of the hail-free area. It does not seem possible from the picture on their website to verify that the white stuff is actually hail; it could be snow. The whole thing could be Photoshop.
Other pages on the site have:
* inconsistent information (every 5.5 seconds; every 6 seconds; every 5 seconds; the noise level is listed at various levels, too...)
* dubious statements like "supersonic explosions do not affect animals"
* incorrect spelling and punctuation
* overuse of jargon and jargon-y words (such as "ascending thermionic explosions"). Looking at this web site, I got the feeling that they did not want me to understand how it works, they just want me to be impressed.
* Worst of all: statistics! Why do they start the noise level measurements 50m away? Are you not supposed to go closer than 50m while it's operating? What if you install this on the roof of your car?
Of course, they don't have to explain their patented super-invention to me. But if they are going to deliberately withhold information, they could have been less patronizing about it! Overall, the site seems to have a very low level of professionalism. To whatever degree this reflects on the device itself, it reflects poorly.
zach
Is that 120 db pulse every 5 seconds really going to do anything to a giant thundercloud
When I spent my summers as a kid in italy on the farm when ever it looked like hail I would hear a booming sound like cannons. My mother told me it was the cannons that they fired into the clouds to stop the hail from knocking the grapes off the vines.
http://Lenny.com
"Hailstones are formed and begin with a piece of dust in the clouds," he explains. "There is a lot of activity going on, and what we do is to de-ionize that activity in the clouds and keep those dust particles from collecting moisture out of the clouds in turn reacting and forming what we know as a hailstone."
I'm a professor of meteorology. If one of my students had written that drivel I would have flunked 'em!
The microphysics of clouds is very complex. I'd really like to know what mechanism they really are trying to stifle here. Here is a bit on how hail forms. First, some background:
In a rapidly growing cumulonimbus (thunderstorm) cloud, you have a strong updraft (air rising rapidly). This air is contains humid air, which condenses to form liquid cloud droplets as it cools (rising air expands and cools - basic thermodynamics). It is indeed true that cloud droplets condense upon pieces of dust/salt/gunk in the atmosphere, but ionization has very very little to do with it. Many of these so-called condensation nuclei are not ionized. Water will condense upon just about anything if cooled enough.
Eventually this rising, cloudy air reaches heights where temperatures are well below freezing - say -20 degrees C. Water actually does not have to freeze when it is below 0 degrees C, and in fact what leads to lots of hail is the fact that there is an abundance of supercooled (below freezing liquid) cloud droplets in this cloud.
Eventually some ice crystals form, either spontaneously (supercooled cloud droplets freeze at about -40 degrees C - this is called homogeneous nucleation of ice), or because they come in contact with an ice nucleus (something that has a similar crystal structure to water ice). These ice crystals fall and co-mingle with the supercooled cloud droplets. Due to the difference in saturation vapor pressures over ice and water at a given temperature, these ice crystals grow and grow at the expense of the cloud droplets without actually making physical contact!
Now the stage is set for hail. There is an abundance of supercooled cloud droplets, which freeze upon contact with ice crystals. Contact is made, and graupel is formed. Graupel is kind of an intermediate form of ice between snow and hail. The updraft of the storm keeps everything going, and in fact can suspend heavy hail particles for a while before they either become so heavy they fall through the updraft, or they are tossed horizontally to a part of the storm where they fall to the ground. The largest hailstones form with the strongest updrafts because the hail can acrete lots and lots of supercooled water (hail will melt and refreeze also as it rises and falls within the cloud).
Again, I simply cannot fathom what process they are trying to stifle with these sound waves. Hail suppression research has focused mainly on seeding clouds with silver iodide. Silver iodide is a powdery substance which has an ice crystal shape very similar to that of water ice. Overseeding a cloud with AgI, so the theory goes, will convert all that supercooled cloud water into small ice crystals, scavenging all the liquid so there won't be any "lucky" graupel particles growing to the size of hail stones.
The Russians claimed some success with this process during the cold war (launching AgI laced rockets into clouds) but frankly I think they were overstating their success. Hail suppression work reached its peak in the 70's but because of the lack of any real statistical success, funding for this kind of work has pretty much dried up.
Anyway, a sucker is born every minute.
Leigh Orf
A squid eating dough in a polyethylene bag is fast and bulbous, got me?
This irritated me so much I looked it up. From HailShield.com:
and
So there we have it. They do move cations into the atmosphere, but they don't shoot them out of the cannon.
I say we take-off and slashdot the site from orbit... it's the only way to be sure
Did you even read the article? This is the ninth one installed in the United States. There are 400 world wide, ... its primary use is to protect crops...
And you think it doesn't work? How'd they sell 400 of the things? When's the last time you saw an apple with hail damage? Did you think it had just stopped hailing?
As for changing nature, sweet jeebus, we're humans we change nature to suit us all the time, or did you think crops just naturally formed in large patches of ground? You're surfing the net, if you have a CRT monitor you have electrons shooting out into your face right now. Did you think that someone just found it on the beach?
The basic principle is that nature is not as fragile as it's portrayed. I don't think shooting a couple of shock waves into the air is going to cause any irreparable damage, and if we didn't screw with nature occasionally we would still be sitting in caves, eating berries and grubs.