SoylentNews is people
SoylentNews
Volkswagen is reversing course on the use of controversial weather-altering technology at a major Mexican car plant after local farmers complained that the system caused drought by preventing rainfall.
The German carmaker had installed hail cannons, which fire shockwaves into the atmosphere, at its Puebla site to prevent the formation of ice stones that had been damaging finished vehicles parked outside its facility.
But local farmers said the devices, which were set to fire automatically under certain weather conditions, caused a drought during the months that should have been Mexico’s rainy season.
Gerardo Perez, a farmers’ representative in the area, told the AFP agency that the cannons meant the “sky literally clears and it simply doesn’t rain”.
A group of local farmers claimed that 2,000 hectares (5,000 acres) of crops were affected, and filed a suit claiming 70 million pesos (€3.2m) in damages from the carmaker, AFP reported.
In response, VW said it would install netting above the cars to protect them from hailstorms in the future.
[...] The carmaker invested in the hail cannon technology to prevent damage to its vehicles earlier this year.
[...] Hail storms present significant problems for car manufacturers, which often have large numbers of finished vehicles parked outside at distribution centres or plants.
Also at UPI, C|Net, MSN, and Business Insider:
Instead of using smoke or projectiles, modern hail cannons — like those used at the Puebla Volkswagen plant — rely on loud shockwaves, fired repeatedly every few seconds as a storm approaches.
"This shockwave, clearly audible as a large whistling sound, then travels at the speed of sound into & through the cloud formations above, disrupting the growth phase of the hailstones," the manufacturer wrote.
Winemakers and auto manufacturers make use of the cannons to try to protect their valuable goods. In 2007, a California NPR station reported that winemakers were using the cannons to try to prevent hail formation.
[...] But still, no one knows if the cannons actually work.
"Scientists say there is no way to prove if these cannons really work, but farmers say it is cheaper to try the cannons than to buy hail insurance," reported NPR, in that story.
"There's no evidence that they actually do anything," meteorologist Harold Brooks of the National Oceanic & Atmospheric Administration's Severe Storms Laboratory told Automotive News in 2005. "It may be possible. But if they really do something, they're doing it through some unknown science that we don't know about."
Skeptics have also pointed out that like hail cannons, thunder produces loud shockwaves — but hail shows up anyway.
(Score: 3, Interesting) by c0lo on Saturday August 25 2018, @07:31AM (3 children)
FTFY - given that the cited deals with the "hail suppression and prevention".
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 0) by Anonymous Coward on Saturday August 25 2018, @08:41AM (2 children)
Thanks. Well, I never saw it hail! It must have worked!
( But then, how much hail has been seen anywhere in Florida? )
But what I was trying to get at is did the sonic booms deter rain like the farmers are claiming VW's booming did for them?
Maybe do some statistical studies to see if Disneyland ( and their nightly fireworks shows ) affects the local weather? My own gut feeling is if they did anything, they would increase the rain, due to seeding, but a mixed blessing because the seedstock is oxides of heavy metals left over from making the fireworks so colorful. But then, the fireworks probably aren't going near high up enough to do anything anyhow.
When I saw this story, my impression is a tempest in a teapot, as I have a hard time believing the booming is capable of either of the results attributed to it. I would have a much easier time believing the farmers claiming their cows don't get rest and are too worked up to give a good pail of milk. I know my animals go beserk on fireworks holidays. My cat simply disappears, and its about two days later I see her again.
(Score: 3, Interesting) by c0lo on Saturday August 25 2018, @10:08AM
It is not impossible.
For the moment, there's not enough studies of what happens in large spaces under natural conditions.
The problem of fog droplet stability was approached quite a good way back (Maxwell, if my memory serves), with limited (due to the need of control) spaces being used experimentally even today [google.com].
If my memory serves, the rate of a droplet evaporation is inverse proportional with the square of its radius - the smaller the drop the faster will evaporate. And the square law is true for condensation conditions - the larger the condensation area, the more condensation.
Leads to an interesting phenomenon around the vapour saturation state in which large drops tend to favour condensation, while small droplets tend to evaporate. Theoretically, fog can only form if seeded - dust, electrical charges (e.g, ionisation from natural radiation), presence of hygroscopic substances (acids, nitrogen oxides), etc - that's my memory of one thermodynamics lesson in my Uni time.
Now, imagine a situation in which rain is barely "willing" to form - close to, just barely over, water vapor saturation point, flat winds, etc. - and you throw some non-negligible sound energy into it by the use of canons. What's you feeling that energy will do to the temperature around cloud formation zone?
Would this be easy to prove under natural conditions? I really don't thinks so.
Is it possible to happen? If the conditions are right, I think it can happen that the use of a sound cannon to disperse a "reluctantly forming rain". Certainly, it won't disperse a heavy rain.
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 2) by c0lo on Saturday August 25 2018, @11:49AM
Theory of heat - JC Maxwell [archive.org]
See PDF page 313 - book page 293.
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford