Skysåing (Cloud seeding). Hva menes?

Skysåing eller seeding er en form for værmodifisering, et forsøk på å få nedbør til å falle fra skyer, ved å tilføre partikler i luften som fungerer som skykondensasjonskjerner eller iskjerner, som forandrer de mikrofysiske prosessene i skyen.

Hvordan lager sølvjodid regn?
Sølvjodid eller tørris (fast karbondioksid) brukes til å forsyne naturlig mangelfulle skyer med riktig konsentrasjon av iskrystaller for å øke nedbøren gjennom prosessen med "kaldt regn". Forskere sier at værmodifiseringsprosessen kan øke nedbøren med 15-24 prosent i gjennomsnitt.

Utviklet på slutten av 1940-tallet, er skysåing definert som en bevisst behandling av skyer for å øke nedbør. Ved luftsprøyting (ved hjelp av fly, og til tider raketter), kan visse kjemikalier som natriumklorid (vanlig salt) og sølvjodid (et annet ikke-giftig kjemikalie) øke nedbøren. Forskere som jobbet for det USA - baserte General Electric Research Laboratory ( gerl ) perfeksjonerte teknikken på 1940- og 1950-tallet. Den nobelprisvinnende kjemikeren fra 1932, Irving Langmuir, og hans stedfortreder Vincent J Schaefer er kreditert for deres banebrytende arbeid på dette feltet.
Prosessen Millioner av tonn vann i form av damp, dråper og ispartikler strømmer konstant i atmosfæren. Skyer består enten av små dråper eller iskrystaller; til tider er de en kombinasjon av begge. Dråpene er så små at det tar en million eller mer for å produsere en enkelt regndråpe. For å danne en sky, dannes dråpene først rundt mikroskopiske partikler av støv, røyk, saltkrystaller, jord og andre materialer som er rikelig tilstede i atmosfæren. Forskere klassifiserer disse partiklene som skykondensasjonskjerner. Blant disse partiklene er det noen få spesielle, som er kjent som isdannende kjerner; på disse vanndråpene kondenserer (på grunn av deres evne til å absorbere vann). Generelt er det mangel på de spesielle kjernene (dette kan være en årsak til nedbørsvariasjonene).

Prosessen med kondensering av dråpene er veldig viktig. Det skjer når lufttemperaturen synker; med det reduseres luftens kapasitet til å holde på vanndamp. Hvis avkjølingen fortsetter, kommer et punkt hvor mengden vann som luften kan holde når sin maksimale kapasitet. Denne temperaturen kalles duggpunktet. På dette tidspunktet begynner vanndamp å kondensere til små dråper.

Kondenseringsprosessen kan være av to typer - "varmt regn" og "kaldt regn". Sistnevnte skjer i tropiske strøk; prosessen kalles så fordi nedbør faller fra skyer der temperaturen er over 0 c. Regn dannes i de 'varme skyene' når større vanndråper kolliderer med og absorberer mindre. Stoffer som er i stand til å absorbere fuktighet fra atmosfæren - som vanlig salt - brukes til å indusere "varmt regn".

Den "kalde regn"-prosessen oppstår når temperaturen, i alle eller noen deler av en sky, er mindre enn 0 c. Disse skyene er vanligvis sammensatt av både iskrystaller og vanndråper. Krystallene vokser raskt, og trekker fuktighet fra de omkringliggende vanndråpene, til vekten får dem til å falle. Mens de faller, kan krystallene smelte og gå sammen med små flytende vanndråper; de kan deretter danne seg til regndråper på en måte som ligner på prosessen med "varmt regn". Hvis krystallene ikke smelter, kan de vokse til store snøflak ved agglomerering og nå bakken som snø. Sølvjodid eller tørris (fast karbondioksid) brukes til å forsyne naturlig mangelfulle skyer med riktig konsentrasjon av iskrystaller for å øke nedbøren gjennom prosessen med "kaldt regn".

Forskere sier at værmodifiseringsprosessen kan øke nedbøren med 15-24 prosent i gjennomsnitt. Imidlertid er suksessraten så lav som 30 prosent, for forskere er ikke sikre på vitenskapen om skydannelse, og ikke alle skyer er regnbærende. Noen ganger forekommer dessuten nedbør bare i små mengder, eller ikke i det hele tatt, fordi visse nødvendige forhold ikke er tilstede. De viktigste forholdene (både initiering av nedbør og å bestemme mengden) er som følger: de vertikale og horisontale dimensjonene til skyene; levetiden til skyene; størrelsene og konsentrasjonene av skydråper og ispartikler. Under riktige forhold kan seeding av skyen til og med gunstig endre en eller flere av disse faktorene.

Prosessen er imidlertid ublu dyr. Skjønt gerlhadde proprietære rettigheter til teknologien, satte den prosessen i det offentlige domene, i frykt for problemer med rettssaker hvis den ble brukt av private selskaper for å indusere nedbør i allerede regnrike regioner. Selv om det ellers er ufarlig, kan såingen føre til rikelig nedbør i utilsiktede områder, og føre til flom. Imidlertid har Kina brukt teknikken til sitt fulle potensiale i provinser med lite regn, spesielt de som ligger i de nordlige delene av landet.

OVERSETTELSE TILKOMMER

Is silver iodide harmful?

However, silver iodide, the chemical most commonly used to seed clouds is known to be toxic and is regulated under the Clean Water Act as a hazardous substance.

What does silver iodide do to the atmosphere?

Upon reaching the cloud, the silver iodide acts as an ice forming nuclei to aid in the production of snowflakes. DRI’s operation generally runs during the winter season of November to May, when storm systems are actively moving through our project areas.

What are the dangers of cloud seeding?

While we don’t know specifically if cloud seeding poses a threat, some experts believe that it could lead to silver toxicity and environmental concerns if the practice becomes common on a much larger scale. Similarly, people worry that cloud seeding could throw off earth’s natural balance of moisture.

What happens when silver iodide is sprayed on clouds?

Yes, it is possible to cause artificial rain by spraying silver iodide on the clouds. Clouds are colloidal in nature and carry charge. Spray of silver iodide, an electrolyte, results in coagulation leading to rain.

How long does cloud seeding take?

The onset of seeding effects can range from almost immediate to up to 30 minutes depending on the seeding delivery method (direct injection at cloud top, or base seeding – releasing seeding agent in the updraft below the cloud base).

Is silver iodide addictive?

“Silver iodide is basically a dangerous drug. In addition to being a bleach and an explosive, it is extremely addictive,” chemical biologist Sam Reeves with the University of Bolivia said. “In concentrated doses, silver iodide offers a short, but very intense high.

Does silver iodide dissolve in water?

Silver iodide is highly insoluble in water and has a crystalline structure similar to that of ice, allowing it to induce freezing (heterogeneous nucleation) in cloud seeding for the purpose of rainmaking. The crystalline structure adopted by silver iodide changes with temperature

How artificial rain is created?

Artificial rain is caused by spraying salt over clouds. As we know rainfall occurswhen oppositely charged clouds meet, since, clouds are colloidal in nature and carry charge. Spray of silver iodide, an electrolyte, leads to artificial rain. Sometimes electrified sand is also used for this purpose.

How is silver iodide used in artificial raining?

Solid silver iodide is preferred as a nucleator for artificially stimulated rain because its crystal lattice parameters are close to those of ice, and for that reason are more effective than other salts in causing small ice crystals in clouds to melt.

What element is used in cloud seeding?

cloud seeding

carbon dioxide (dry ice) and silver iodide have been the most effective; when used in supercooled clouds (composed of water droplets at temperatures below freezing), they form nuclei around which the water droplets evaporate.

How do you make artificial clouds?

Clouds form from the condensation or freezing of water vapor.

  1. Form the water vapor. Fill a jar with 2 inches (5 cm) of warm water and stir. …
  2. Form smoke particles. Ask an adult to light a match, blow it out and quickly drop it into the jar. …
  3. Cool it. …
  4. Watch the cloud appear. …
  5. Make it disappear. …
  6. The real deal.

What are the signs of silver poisoning?

Overexposure to silver may cause a gray discoloration of the skin, hair and internal organs. Additional symptoms may include nausea, vomiting, and diarrhea. Zinc overexposure may cause the flu-like symptoms of metal fume fever; stomach and intestinal disturbances; and/or liver dysfunction.

What happens when silver iodide is exposed to sunlight?

When silver iodide Crystal are exposed to sunlight the silver ion gets reduced to silver metal and iodide ions are oxidized to iodine gas. 2 moles of Silver iodide gives 2 moles of silver metal and 1 mole of iodine gas. Application of this reaction is in silver based photography.

Is silver iodide flammable?

Appearance and Odor: Light yellow, odorless powder, slowly darkened by light. Fire and Explosion Hazard: Negligible fire and Negligible explosion hazard in dust form when exposed to heat or flame.

Why is silver iodide yellow?

bromide ions give a cream precipitate of silver bromide. iodide ions give a yellow precipitate of silver iodide.

What is the purpose of washing silver iodide with distilled water?

Filtration separates insoluble substances from liquids and solutions. The precipitate is insoluble in water, so any remaining contaminating solution can be removed by washing it with distilled water.

Does silver dissolve in water?

Solubility of silver and silver compounds

Under normal conditions silver is water insoluble. This also applies to a number of silver compounds, such as silver sulphide. Some other sulphur compounds are more or less water soluble. For example, silver chloride has a water solubility of 0.1 mg/L, maximum.

Søk etter: Does silver dissolve in water?

Is silver iodide a strong electrolyte?

Silver rubidium iodide (RbAg415) is a unique solid electrolyte because of its extremely high con- ductivity which has an almost negligible electronic contribution. This characteristic makes RbAgJ, a very promising electrolyte for the development of high-power solid-state batteries.2. aug. 2021

Silver rubidium iodide solid electrolyte – Wiley Online Library

https://onlinelibrary.wiley.com › pdf › jctb.5020210802

Søk etter: Is silver iodide a strong electrolyte?

Does silver iodide dissolve in ammonia?

The silver iodide is so insoluble that ammonia cannot lower the silver ion concentration enough for the precipitate to dissolve.21. aug. 2020

Testing for Halide Ions – Chemistry LibreTexts

https://chem.libretexts.org › Group_17:_The_Halogens

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Is silver iodide soluble in ethanol?

silver iodide behaves as a sparingly soluble salt in solutions of sodium iodide in water, methyl alcohol, and ethyl alcohol.

The Solubility of Silver Iodide in Solutions of Alkali Iodide in Acetone.

https://pubs.rsc.org › content › articlepdf

Søk etter: Is silver iodide soluble in ethanol?

How toxic is silver iodide?

Iodine in AgI poses no environmental danger. Organic seeding agents currently being proposed are not likely to be toxic in either the short or the long run, but dispersal of proprietary organic compounds should be prohibited unless their composition is fully revealed.

Ecological effects of silver iodide and other weather modification agents …

https://agupubs.onlinelibrary.wiley.com › doi › abs

Søk etter: How toxic is silver iodide?

How do you make silver iodide?

Part of a video titled Make Silver Iodide - YouTube

0:00

0:52

Next get some potassium iodide. And we’re going to dissolve in the water. Next to that we are goingMore

What happens when silver iodide is sprayed on the clouds?

Yes, it is possible to cause artificial rain by spraying silver iodide on the clouds. Clouds are colloidal in nature and carry charge. Spray of silver iodide, an electrolyte, results in coagulation leading to rain.

It is possible to cause artificial rain by spraying silver iodide on the clouds …

https://www.toppr.com › ask › question › it-is-possible-to-…

Søk etter: What happens when silver iodide is sprayed on the clouds?

Who invented cloud seeding?

meteorologist Vincent J. Schaefer

The first experiments with cloud seeding were conducted in 1946 by American chemist and meteorologist Vincent J. Schaefer, and since then seeding has been performed from aircraft, rockets, cannons, and ground generators.

cloud seeding | atmospheric science – Encyclopedia Britannica

https://www.britannica.com › science › cloud-seeding

Søk etter: Who invented cloud seeding?

Why is silver iodide used for cloud seeding?

Most cloud seeding operations, including those run by DRI, use a compound called silver iodide (AgI) to aid in the formation of ice crystals. Silver iodide exists naturally in the environment at low concentrations, and is not known to be harmful to humans or wildlife.

What is Cloud Seeding? – DRI – Desert Research Institute

https://www.dri.edu › cloud-seeding-program › what-is-cl…

Søk etter: Why is silver iodide used for cloud seeding?

Is silver iodide addictive?

“Silver iodide is basically a dangerous drug. In addition to being a bleach and an explosive, it is extremely addictive,” chemical biologist Sam Reeves with the University of Bolivia said. “In concentrated doses, silver iodide offers a short, but very intense high.15. sep. 2016

Cloud Seeding May Be Affecting Your Health – TPGS

https://thatsprettygoodscience.com › 2016/09/15 › cloud-s…

Søk etter: Is silver iodide addictive?

What is a cloud made of?

Bilderesultat

Clouds appear when there is too much water vapour for the air to hold. The water vapour (gas) then condenses to form tiny water droplets (liquid), and it is the water that makes the cloud visible. These droplets are so small that they stay suspended in the air.

What are clouds and how do they form? – Met Office

https://www.metoffice.gov.uk › weather › types-of-weather

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Why is AgI used in artificial rain?

Hence, $AgI$ acts as an ice nucleus and causes ice crystals to form and grow. Silver iodide increases the number of cloud condensation nuclei around (CCN) which water vapor may form microscopic water droplets. This is why silver iodide is used in artificial rains.

Silver iodide is used for producing artificial rain class 11 chemistry CBSE

https://www.vedantu.com › question-answer

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What is warm rain?

Bilderesultat

Warm rain results from the joining together of a cloud’s liquid water droplets. For the rain to be warm, temperatures throughout the cloud must be above freezing, so ice particles are absent. Rainmaking is not easy.12. aug. 2019

What is warm rain? | The Weather Guys

https://wxguys.ssec.wisc.edu › 2019/08/12 › warm-rain

Søk etter: What is warm rain?

Where is silver chloride used?

Bilderesultat

What are the uses of silver chloride? AgCl has several disinfectant and antiseptic properties and is also used in the treatment of mercury poisoning. This compound finds use in antimicrobials, wound healing materials, personal deodorants, water treatment, and antidotes.

Silver Chloride – Structure, Properties, and Uses of AgCl – Byju’s

https://byjus.com › chemistry › silver-chloride

Søk etter: Where is silver chloride used?

How long does cloud seeding take?

The onset of seeding effects can range from almost immediate to up to 30 minutes depending on the seeding delivery method (direct injection at cloud top, or base seeding – releasing seeding agent in the updraft below the cloud base).

LOUD SEEDING – ND Water Commission

https://www.swc.nd.gov › arb › ndcmp › pdfs

Søk etter: How long does cloud seeding take?

What does silver iodide smell like?

The compound is a bright yellow solid, but samples almost always contain impurities of metallic silver that give a gray coloration.

Silver iodide.

Names
Odorodorless
Density5.675 g/cm3, solid
Melting point558 °C (1,036 °F; 831 K)
Boiling point1,506 °C (2,743 °F; 1,779 K)

36 rader til

Silver iodide – Wikipedia

https://en.wikipedia.org › wiki › Silver_iodide

Søk etter: What does silver iodide smell like?

Is silver iodide dry ice?

Silver iodide or dry ice (solid carbon dioxide) is used to supply naturally deficient clouds with the proper concentration of ice crystals to increase rainfall through the ‘cold rain’ process.

Silver iodide lining – Down To Earth

https://www.downtoearth.org.in › coverage › silver-iodide…

Søk etter: Is silver iodide dry ice?

Does Dubai do cloud seeding?

Why do we need cloud seeding?

Which gas is used in artificial rain?

The correct answer is option 1 i.e Silver Iodide. Artificial rain is produced by seeding clouds with Silver Iodide. Cloud seeding is the process of making precipitation fall using substances like dry ice, and silver iodide.

[Solved] Artificial rain is produced by seeding clouds with – Testbook.com

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