SNOW GROWER? Can human intervention bring on bouts of precipitation such as this week's snowstorm in China?
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At long last, it snowed in northern China. The first snow of the year came to Hebei, the northern province surrounding Beijing. In the Chinese capital, it was the first real bout of precipitation since last October. The blizzard caused 12 area highways around Beijing to close.
Travel inconveniences aside, the blast of moisture was more than welcome in China, which is suffering through its worst drought in decades. Earlier this week, government officials announced that even the country's massive water projects, like the North-South Water Transfer Project, couldn't hope to deal with future shortages—the country would have to cut back its demand as well.
It should come as no surprise, then, that the Chinese government wanted to claim a little credit for the good weather fortune, and they have. Officials said their cloud-seeding program directly caused the snowstorm. Engineers blasted more than 400 cigarette-size sticks of silver iodide into the sky shortly before the storm, and a senior engineer told Reuters that it was "a procedure that made the snow a lot heavier."
Cloud seeding and other weather-modification schemes have been around for years. But how do they work? And can you really claim that cloud seeding caused a particular storm? We asked cloud-seeding expert Arlen Huggins, associate research scientist in the division of atmospheric sciences at the Desert Research Institute in Reno, Nev., to give us some answers.
[An edited transcript of the interview follows.]
Tell us a little about the basics of cloud seeding.
Clouds, whether in summer or winter, are not perfectly efficient at producing precipitation. There's some part of a storm that's much less than 100 percent efficient in turning clouds into precipitation. In winter, the problem is that there aren't sufficient ice crystals. If droplets fall in liquid form they generally evaporate. The idea is to add ice-forming particles.
Why silver iodide?
One thing people discovered early on is that the structure is very similar to that of ice. The lattice structure at the molecular level is very, very close. We think that's why ice wants to bond to it.
When did scientists get serious about experimenting with cloud seeding?
I think it was the day after they finished the experiments in the lab [chuckles]. The initial discoveries were in the 1940s, with substances like silver iodide. It was a short period before they started trying to affect larger systems, without much success.
Wasn't Kurt Vonnegut's brother one of the lead scientists in the 1940s?
Yeah, Bernard Vonnegut.
[Editor's note: Bernard Vonnegut, the older brother of the late novelist Kurt, uncovered silver iodide's weather-modifying properties as a researcher for General Electric in 1946. He later taught atmospheric science at the State University of New York at Albany before passing away in 1997.]
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17 Comments
Add Commentcan ultrasonic sound waves be ampliefied? For example, if a device emits ultra sonic sound only audible to certain animals, can those sounds be amplified with a megaphone?
Reply | Report Abuse | Link to thisScientific American along with other pretigious science magazines are turning in to typical western China and Iran bashing tabloid. Look at the title of this report. Many Asian countries make tall scientific claims and very same reporters glorify those alleged calims as though no scrutiny is required. However, very same reporters find microscopic scrutiny also insufficient to unearth somethign fishy on Chinese and Iranian scientific achievements. What a Hypocrisy (Oops Democracy).
Reply | Report Abuse | Link to thisIn the "What are the best results..." question, the 300,000 to 500,000 refers to the runoff of a basin in acre-feet of water (1 acre-foot = one foot of water covering an acre), not land area in acres.
Reply | Report Abuse | Link to thisBakerchic, ultrasonic sounds can certainly be amplified (made louder) but that still wouldn't make them detectable by the human ear no matter how "loud" they were. For example, you can't hear a dog-whistle no matter how hard you blow on it. You'd have to feed the sound through some device that changes the frequency of the sound to a frequency humans could hear.
Reply | Report Abuse | Link to thiswell now that we've setttled that,
Reply | Report Abuse | Link to thislet's get rid of all environmentally murderous cities.
water is where you find it, not where you at-great-cost-to-everything carry it
Precipitation taken in one locale takes away from the locale that would normally receive it -- and probably depends on doing so. I can see more use of this technology resulting in friction, animosity and trouble between regions and countries.
Reply | Report Abuse | Link to thisCLOUD SEEDING IS A GOD-GIVEN GIFT TO AUGMENT RAINS.
Reply | Report Abuse | Link to this--------------------------------------------------------------------------
Cloud Seeding is 100% scientific and is highly successful in the hands of genuine and patriotic experts like the Chinese Meteorologists who dedicate their life to resolve farmers'problems of droughts , floods and hail storms by cloud seeding.Today,China produces annual addition of 65 billion cubic meters of rainfall by employing 37000 technicians at a cost benefit ratio of 1:27.
Barak Obama,the U.S.President must advise all his experts in U.S.Universities to visit China and Snowy Mountains to learn their cloud seeding technologies for implementing them in USA and other countries to fight the damaging impacts of the Climate Change.For more details see the following web sites.
http://www.usatoday.com/news/world/2006-06-29-china-rain_x.htm
http://www.snowyhydro.com.au/files/cs_evid0304.pdf
http://www.indiawaterportal.org/blog/2007/11/16/cloud-seeding/
http://shivajirao.cloudseeding.googlepages.com/scienceofcloudseeding
http://www.abc.net.au/rural/content/2007/s1920342.htm
http://www.bom.gov.au/announcements/media_releases/ho/20070509.shtml
prof.T.Shivaji Rao.B.E.,M.S.[Rice,Texas,1962]Ph.D.[Hony]
Director,centre for environment,Gitam University and
Expert,cloud seeding project of Government of A.P.State,India
It is suggested that plenty of scientists and Organisations have tried to write off cloud seeding.This is not true in case of hundreds of patriotic Meteorologists of the Chinese Academy of sciences who researched for more than 40 years and certified that cloud seeding is highly scientific and is the only effective weapon to fight the recurring droughts.see the web site:
Reply | Report Abuse | Link to thishttp://english.people.com.cn/english/200007/14/eng20000714_45496.html
For those scientists who wish to learn the science behind cloud seeding before condemning it,let them see the web sites
http://shivajirao.cloudseeding.googlepages.com/scienceofcloudseeding
http://www.abc.net.au/rural/content/2007/s1920342.htm
For the Question whether any one storm would have snowed anyway,the answer cannot be that we do't know but it should be that even if it were to precipitate,it would only deposit about one-fifth of its water content which has to be augmented by another 15% by seeding it with chemicals.
To the Question if cloud seeding helps to mitigate drought,the answer should not be in the negative.It must be remembered that there will be suitable clouds in the nearby areas and we must seed such clouds and store that additional water for subsequent transfer to the drought-prone areas and thus we should profit by it.
Cloud seeding sounds fundamentally dangerous as a potential accelerant to climate change. Does changing microclimates not ultimately affect how and where rain should be falling naturally and affect natural ecosystems? Forcing rain where it might not otherwise fall means rain may not fall where or should.
Reply | Report Abuse | Link to thisI am not an expert on the subject, and I haven't done a whole lot of research, yet..., but in a quick search I am not seeing this question addressed.
Cloud seeding is a Divine Gift to intelligent people who can grasp why their natural right to safe drinking water ,right to health,right to food,right to livelihood and right to life are taken away by a handful of extremely selfish industrialists in almost all the countries who want to obtain the maximum profits at any cost within the shortest possible time and therby are causing high environmental pollution,ecological degradation,intense forest fires that cause Global warming,sea surface temperature increases that distort the natural weather systems which are responsible for the growing droughts and floods and natural weather hazards and hence man is forced to use cloud seeding to restore the normal precipitation levels.Hence cloud seeding shall not be considered to be dangerous as it does not accelerate climate change impacts.It is man-made global warming and ElNino and forest fires thgat are affecting how and where rain should naturally be falling and thereby impcat the eco-systems and so cloud seeding becomes inevitable to restore Nature's balances.Since normal rainfall is prevented from falling where it should due to man-made pollution and global warming impacts,we have to force clouds to give rain where they should for protecting man and Nature and thereby we are not preventing rain to fall naturally in other places because we are taking out of the atmospheric moisture rivers only less than one percent of their water content and hence we are not harming any one's interests.
Reply | Report Abuse | Link to thisprof.T.shivaji Rao.B.E.,M.S.[Rice,1962]Ph.D[Hony]
Director,centre for Environmental studies,Gitam University,
Expert,Cloud seeding project of Government of Andhra Pradesh.state.india
Change title to"WHY CLOUD SEEDING DOES NOT WORK"?
Reply | Report Abuse | Link to thisI have gone through the various comments on cloud seeding and find there is no reson why intellectuals of United States are still doubting on the utility of cloud seeding when the need of the hour is to promote it on a vast scale on a war-footing to save mankind and Nature from the clutches of a fast enveloping Global Warming Blanket that is waiting in the wings to strangulate Eastern United States,U.k and European states within 2 to 3 years time.After I read the article by prof.T.Shivaji Rao,an international expert on cloud seeding under the web site:http://shivajirao32.googlepages.com/sci%26techofcloudseeding-11,I am very much convinced even as a non-scientist that as admitted by AlGore,scientific facts do not move people to respond to an Emergency unless science is clubbed with ehical,moral and spiritual moorings.
Scientific American must promote ethics,morals and spiritualism among the enlightened academicians,educated students and school teachers to grasp the seriousness of climate change and its impacts on man and Nature so that they can write to the president of USA to take the lead at the forthcoming international gathering of heads of states in copenhagen to take drastic action to save mankind on the verge of extinction due to man-mad crimes resulting in global warming and climate change and for the purpose promote cloud seeding all over the world before it is toolate
T.V.Rama Rao
Why Americans opt for last bench leaving the first to China ?
Reply | Report Abuse | Link to thisAmerica has produced so many intellectuals who use knowledge to secure Nobel laureates by working dedicated in a chosen field of knowledge unlike Chinese who use knowledge to stave off impending weather hazards like droughts,forest fires,floods and global warming by using cloud seeding on the most extensive scale in the world to augment precipitation as the only weapon to fight the Climate change?As a lay man in scientific field,I studied the web site by prof..Shivaji Rao,an international expert on Environment" http://shivajirao32.googlepages.com/sci%26techofcloudseeding-11" and I completely understood it as a pure scientific subject and such a subject is most surprisingly beyond the comprehension of almost all the academic scientists in several universities all over the world.
The reason as AlGore has put it in case of lack of even a trace of public response for the emerging killer climate change,is due to absence of ethics,morals and spiritual values among scientists who know the threatening facts but refuse to move in public interest. Cloud seeding is as prof.Shivaji Rao puts it is the only weapon to fight the impending perils of climate change and intellectuals must become wise to use this knowledge and put to public use without wasting time to demand for more Federal Grants for some more peripherial research and for the purpose throw spanners in the accelerating program of cloud seeding,the basic need to quench the thirst of millions of people ,cattle and parching lands in many countries.It is high time that scientists must learn to develop humanism because all religions preach that
"Love of Fellowmen is Love of God,and
Service to Fellowmen is service to God.
Mahatma Gandhiji also emphasised that Science without humanism is a social crime and scientists cannot forget it.
T.Rama Rao.M.Com.,
Under the guidelines of the Clean Water Act by the EPA, silver iodide is considered a hazardous substance, a priority pollutant, and as a toxic pollutant.(10)
Reply | Report Abuse | Link to thisUnder the guidelines of the Clean Water Act by the EPA, silver iodide is considered a hazardous substance, a priority pollutant, and as a toxic pollutant.(10), so based off of this, it would be irrational to support cloud seeding at this current time. *I am fine with acid rain and radioactive isotopes being rained on me as it is, I do not wish to add anything else to the party. (*Please note the sarcasm)
Reply | Report Abuse | Link to thisBack in 1969 when I was attending Montana State University in Bozeman a fairly big-budget cloud seeding project was in the Bridger mountains north of town. I was one of the technicians hired to climb the chosen mountain and stay in a tiny shelter next to a large propane burner that operated like a jet engine aimed at the sky. I also had to tromp around to instrument stations on the mountaintop every four hours 24/7 to take the readings.
Reply | Report Abuse | Link to thisOnce a month when the air was cold enough to be exceptionally dense, a helicopter would strain to bring up 500 gallon tanks of silver oxide and similar tanks of propane. The slurry would be injected into the jet, carrying the particles away in the ascending heated air.
Years later I came across the research director of that project at a water conference and he was very evasive about whether the results proved anything or not. By some type of coincidence, I am sure, the downwind snow zone of this experiment covered the popular Bridger Bowl ski area, but I observed that the ski bowl people did not think it worthwhile to take over this operation when the government money ran out.
Intelligent people who can grasp why
Reply | Report Abuse | Link to this- their safe drinking water, healthy food, livelihood and right to life are taken away by a handful of extremely selfish industrialists who want to obtain maximum profits at any cost, and in the shortest possible time, and are causing extreme environmental pollution, ecological degradation, intense forest fires that cause Global warming, sea surface temperature increases that distort the natural weather systems which are responsible for the growing droughts and floods and natural weather hazards,
- these intelligent people are turning to cloud seeding and spraying everyone like roaches without their permission or knowledge, with silver iodide and any number of other secret ingredients, and without any environmental impact review, and are causing massive global environmental pollution, ecological degradation, and distorting the natural weather systems and are responsible for growing the droughts. They are taking away our natural right to clean air, right to health, right to healthy food, right to a healthy livelihood and right to life.
They seem like a handful of extremely self esteemed and well meaning scientists who in almost all countries want to obtain the most rainfall at the lowest cost within the shortest possible time. They have a lot of vanity and actually think they can do it at no cost to the planet or their neighbors on it. So they team up with a handful of extremely selfish industrialists who want to obtain the maximum profits at any cost within the shortest possible time, to mass produce their cloud seeding plans. So now all man is forced to use cloud seeding and I guess to buy the cloud seeding products, which I guess can turn some of those scientists into wealthy industrialists.
Why don't the scientists join with the other intelligent people who understand the need for democracy and a precautionary principle and a concern for cloud seeding's environmental and health impacts?
Intelligent people who can grasp why
Reply | Report Abuse | Link to this- their safe drinking water, healthy food, livelihood and right to life are taken away by a handful of extremely selfish industrialists who want to obtain maximum profits at any cost, and in the shortest possible time, and are causing extreme environmental pollution, ecological degradation, intense forest fires that cause global warming, sea surface temperature increases that distort the natural weather systems which are responsible for the growing droughts and floods and natural weather hazards,
- these intelligent people are turning to cloud seeding and spraying everyone like roaches without their permission or knowledge, with silver iodide and any number of other secret ingredients, and without any environmental impact review, and are causing massive global environmental pollution, ecological degradation, and distorting the natural weather systems and are responsible for growing the droughts. They are taking away our natural right to clean air, right to health, right to healthy food, right to a healthy livelihood and right to life.
They seem like a handful of extremely self esteemed and well meaning scientists who in almost all countries want to obtain the most rainfall at the lowest cost within the shortest possible time. They have a lot of vanity and actually think they can do it at no cost to the planet or their neighbors on it. So they team up with a handful of extremely selfish industrialists who want to obtain the maximum profits at any cost within the shortest possible time, to mass produce their cloud seeding plans. So now all man is forced to use cloud seeding and I guess to buy the cloud seeding products, which I guess can turn some of those scientists into wealthy industrialists.
Why don't the scientists join with the other intelligent people who understand the need for democracy and a precautionary principle and a concern for cloud seeding's environmental and health impacts?