The super floods devastating the life of common people in Pakitan, destruction of crops, damage to bridges, death and injuries are the result of nature or an Artificial rain.
I am posting some related articles kindly peruse:
How is artificial rain produced?
R.Narasimhan, Chennai
ANSWER 1: The need to develop and improve rain-making techniques in terms of design, operation, monitoring and evaluation by giving them a more scientific character is today's need.
This includes using computers to study cloud formations and help the rain-making operations achieve the goals of the project. The role of weather modification, or rain-making, is an important component in water resource management.
The process involved in artificial rain-making involves three easy-to-understand stages. The first stage is agitation. That is using chemicals to stimulate the air mass upwind of the target area to rise and form rain clouds.
The chemicals used during this stage are calcium chloride calcium carbide, calcium oxide, a compound of salt and urea, or a compound of urea and ammonium nitrate. These compounds are capable of absorbing water vapour from the air mass, thus stimulating the condensation process.
The second stage is called building-up stage. Here the cloud mass is built up using chemicals such as kitchen salt, the T.1 formula, urea, ammonium nitrate, dry ice, and occasionally also calcium chloride to increase nuclei which also increase the density of the clouds. In the third stage of bombardment chemicals such as super-cool agents: silver iodide and dry ice are used to reach the most unbalanced status which builds up large beads of water (Nuclei) and makes them fall down as raindrops.
In planning every stage a high degree of expertise and experience is required, in selecting the types and amounts of chemicals to be used, while taking into consideration weather conditions, topographical conditions, wind direction and velocity as well as the location or delimitation of the area for chemical seeding. Several other ideas are also involved in rain making. Rockets containing rain-making chemicals can be fired into the clouds either from the ground or from aircraft.
A jet of rain-making chemicals is shot from a highly pressurised cannister directly into the cloud base, so as to coerce clouds which normally hang above mountain tops to cluster up and rain on the mountain or their slopes.
Rain-making chemicals are added to super-cooled clouds, i.e., those at altitudes above 18,000 metres, to stimulate the formation of ice crystals in the cloud or cloud cluster.
The Hindu S&T desk
* * *
ANSWER 2: Artificial rain is produced by spraying clouds with substances like Silver Iodide (costly) or cheaper ones like solid carbon dioxide (dry ice) or even finely powdered Sodium Chloride. The process is called seeding.
Often there are clouds, but no rain. This is because of a phenomenon called supercooling. The temperature of the cloud might be close to zero and there might even be crystals of ice in it.
The water vapour in the cloud does not condense to liquid water. The super cooling gets disturbed by spraying the cloud with the chemicals mentioned above, using a small aeroplane for the purpose.
The `super' phenomena (cooling, heating, saturation etc.) are perverse in a sense. Very pure water when heated in a clean vessel, often does not start boiling when expected. Crystals of the photographer's hypo (Sodium thiosulphate) easily dissolve in a little water when heated. But on cooling, crystals do not separate out.
If the vessel is shaken vigorously, or if a small crystal of hypo is freshly added, then crystallization starts immediately.
Making artificial rain is a similar way of intervening in the super cooling phenomenon.
-------------
Artificial Rain in Dubai
By Altaf Sayani on July 7th, 2008 in Interesting | No Comments
Dubai residents got a nice rain which helped to get cooled in this summer.
Can you believe?
It was an artificial rain done by the Meteorological department at the National Center of Meteorology and Seismology (NCMS) to remove the air pollution on Dubais atmosphere.
It is called Cloud Seeding a latest technology to customize weather. Could seeding, a form of weather modification, is the attempt to change the amount or type of precipitation that falls from clouds, by dispersing substances into the air that serve as cloud condensation or ice nuclei. The usual intent is to increase precipitation, but hail suppression in also widely practiced. Silver iodide and dry ice are the most commonly used substance in the cloud seeding sprayed by an
aircraft putting dry ice or silver iodide on clouds which makes artificial rain.
Indian scientists set to create artificial rain
Updated on Sunday, June 28, 2009, 11:57
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New Delhi, June 28: If it doesn't rain, it might still pour! That's what some Indian scientists are hoping to achieve with a national cloud seeding programme at a time when there's uncertainty about the arrival and intensity of the monsoon this year.
Scientists at the Pune-based Indian Institute of Tropical Meteorology (IITM) are set to create artificial rain with this programme.
Cloud seeding is the process of introducing chemicals (either dry ice or more commonly, silver iodide aerosols, potassium and sodium chloride) into the upper part of clouds to try to stimulate the precipitation process and get rain.
"Scientists at the IITM have started the experiment to create artificial rain. It is a three-year project launched in May and, based on the feedback, the government will take a call on its implementation," Shailesh Nayak, secretary at the Earth Sciences Ministry, told IANS.
The IITM, a premier research institute under the government, launched the Cloud Aerosol Interaction and Precipitation Enhancement Experiment (Caipeex) on May 17, 2009, to study cloud seeding.
"It is a national programme which will help in providing a scientific basis for the operational way of cloud-seeding. For the last 20 years we have been experimentally undertaking cloud-seeding activity successfully and an 11-year cloud seeding project between 1973 and 1984 showed increase in rainfall by 20 percent," JR Kulkarni, programme manager at Caipeex, said.
The experiment will be carried out in three phases. During the first phase (May-October), the scientists have been observing different monsoon clouds over the country using an aircraft with special equipment.
"The aircraft is equipped with a special instrument to measure cloud parameters - temperature, wind, liquid water droplets - and aerosol background. This data will provide us with properties of clouds in different parts of the country," said Kulkarni.
The IIMT has already studied clouds in western and northern parts of India and the team is likely to finish the southern region by June-end.
During the second phase (June-September 2010), random cloud seeding experiments will be carried out, using the aircraft equipped for seeding and the one containing the special equipment.
"Based on the properties of clouds, we will start the seeding programme across India. The seeding aircraft will spray hygroscopic particles (salts) that can broaden water droplets in clouds and hasten the onset of precipitation formation," said Kulkarni.
In the third phase (2011-12), scientists will measure and analyse the seeding impact.
"A dense network of automatic rain gauges will be installed in the experimental area to measure the rainfall. Rain water samples will be collected from the seeded and non-seeded clouds. The chemical analysis of rain water samples will be carried out to understand the effect of seeding on the precipitated water," he said.
"The experiment will give us an idea which areas are conducive for cloud-seeding and the amount of increase in rainfall after the experiment," he added.
Many other organisations, including the Indian Institute of Technology-Kanpur, the National Aerospace Laboratory, Bangalore, the Indian Air Force and the Indian Navy, are participating in the project.
China presently has the largest cloud seeding system in the world. It used cloud seeding in Beijing just before the 2008 Olympic Games in order to clear the air of pollution. In February 2009, China also used iodide sticks to artificially induce snowfall over Beijing after four months of drought.
A total of 24 countries currently practice weather modification operationally.
ARTIFICIAL RAINFALL
..[cloud seeding
INTRODUCTION
Artificial rainfall is also known as Cloud Seeding. Cloud seeding is a weather modification system that aims to boost precipitation or rain by introducing condensation nuclei such as salt or dry ice.
1st Stage
The first stage is Agitation. That is using chemicals to stimulate the air mass upwind of the target area to rise and form rain clouds. The chemicals used during this stage are calcium chloride, calcium carbide,
calcium oxide, a compound of salt and urea, or a compound of urea and ammonium nitrate. These compounds are capable of absorbing water vapor from the air mass, thus stimulating the condensation process.
2nd Stage
The second stage is called Building-up stage. Here the cloud mass is built up using chemicals such as kitchen salt, the T.1 formula, urea, ammonium nitrate, dry ice, and occasionally also calcium chloride to increase nuclei which also increase the density of the clouds.
3rd Stage
In the third stage of bombardment chemicals such as super-cool agents:
silver iodide and dry ice are used to reach the most unbalanced status which builds up large beads of water (Nuclei) and makes them fall down as raindrops. The process is called seeding.
SMIQBAL.
I am posting some related articles kindly peruse:
How is artificial rain produced?
R.Narasimhan, Chennai
ANSWER 1: The need to develop and improve rain-making techniques in terms of design, operation, monitoring and evaluation by giving them a more scientific character is today's need.
This includes using computers to study cloud formations and help the rain-making operations achieve the goals of the project. The role of weather modification, or rain-making, is an important component in water resource management.
The process involved in artificial rain-making involves three easy-to-understand stages. The first stage is agitation. That is using chemicals to stimulate the air mass upwind of the target area to rise and form rain clouds.
The chemicals used during this stage are calcium chloride calcium carbide, calcium oxide, a compound of salt and urea, or a compound of urea and ammonium nitrate. These compounds are capable of absorbing water vapour from the air mass, thus stimulating the condensation process.
The second stage is called building-up stage. Here the cloud mass is built up using chemicals such as kitchen salt, the T.1 formula, urea, ammonium nitrate, dry ice, and occasionally also calcium chloride to increase nuclei which also increase the density of the clouds. In the third stage of bombardment chemicals such as super-cool agents: silver iodide and dry ice are used to reach the most unbalanced status which builds up large beads of water (Nuclei) and makes them fall down as raindrops.
In planning every stage a high degree of expertise and experience is required, in selecting the types and amounts of chemicals to be used, while taking into consideration weather conditions, topographical conditions, wind direction and velocity as well as the location or delimitation of the area for chemical seeding. Several other ideas are also involved in rain making. Rockets containing rain-making chemicals can be fired into the clouds either from the ground or from aircraft.
A jet of rain-making chemicals is shot from a highly pressurised cannister directly into the cloud base, so as to coerce clouds which normally hang above mountain tops to cluster up and rain on the mountain or their slopes.
Rain-making chemicals are added to super-cooled clouds, i.e., those at altitudes above 18,000 metres, to stimulate the formation of ice crystals in the cloud or cloud cluster.
The Hindu S&T desk
* * *
ANSWER 2: Artificial rain is produced by spraying clouds with substances like Silver Iodide (costly) or cheaper ones like solid carbon dioxide (dry ice) or even finely powdered Sodium Chloride. The process is called seeding.
Often there are clouds, but no rain. This is because of a phenomenon called supercooling. The temperature of the cloud might be close to zero and there might even be crystals of ice in it.
The water vapour in the cloud does not condense to liquid water. The super cooling gets disturbed by spraying the cloud with the chemicals mentioned above, using a small aeroplane for the purpose.
The `super' phenomena (cooling, heating, saturation etc.) are perverse in a sense. Very pure water when heated in a clean vessel, often does not start boiling when expected. Crystals of the photographer's hypo (Sodium thiosulphate) easily dissolve in a little water when heated. But on cooling, crystals do not separate out.
If the vessel is shaken vigorously, or if a small crystal of hypo is freshly added, then crystallization starts immediately.
Making artificial rain is a similar way of intervening in the super cooling phenomenon.
-------------
Artificial Rain in Dubai
By Altaf Sayani on July 7th, 2008 in Interesting | No Comments
Dubai residents got a nice rain which helped to get cooled in this summer.
Can you believe?
It was an artificial rain done by the Meteorological department at the National Center of Meteorology and Seismology (NCMS) to remove the air pollution on Dubais atmosphere.
It is called Cloud Seeding a latest technology to customize weather. Could seeding, a form of weather modification, is the attempt to change the amount or type of precipitation that falls from clouds, by dispersing substances into the air that serve as cloud condensation or ice nuclei. The usual intent is to increase precipitation, but hail suppression in also widely practiced. Silver iodide and dry ice are the most commonly used substance in the cloud seeding sprayed by an
aircraft putting dry ice or silver iodide on clouds which makes artificial rain.
Indian scientists set to create artificial rain
Updated on Sunday, June 28, 2009, 11:57
Share
Buzz up!
TRANSLATE INTO:
Powered by Translate
New Delhi, June 28: If it doesn't rain, it might still pour! That's what some Indian scientists are hoping to achieve with a national cloud seeding programme at a time when there's uncertainty about the arrival and intensity of the monsoon this year.
Scientists at the Pune-based Indian Institute of Tropical Meteorology (IITM) are set to create artificial rain with this programme.
Cloud seeding is the process of introducing chemicals (either dry ice or more commonly, silver iodide aerosols, potassium and sodium chloride) into the upper part of clouds to try to stimulate the precipitation process and get rain.
"Scientists at the IITM have started the experiment to create artificial rain. It is a three-year project launched in May and, based on the feedback, the government will take a call on its implementation," Shailesh Nayak, secretary at the Earth Sciences Ministry, told IANS.
The IITM, a premier research institute under the government, launched the Cloud Aerosol Interaction and Precipitation Enhancement Experiment (Caipeex) on May 17, 2009, to study cloud seeding.
"It is a national programme which will help in providing a scientific basis for the operational way of cloud-seeding. For the last 20 years we have been experimentally undertaking cloud-seeding activity successfully and an 11-year cloud seeding project between 1973 and 1984 showed increase in rainfall by 20 percent," JR Kulkarni, programme manager at Caipeex, said.
The experiment will be carried out in three phases. During the first phase (May-October), the scientists have been observing different monsoon clouds over the country using an aircraft with special equipment.
"The aircraft is equipped with a special instrument to measure cloud parameters - temperature, wind, liquid water droplets - and aerosol background. This data will provide us with properties of clouds in different parts of the country," said Kulkarni.
The IIMT has already studied clouds in western and northern parts of India and the team is likely to finish the southern region by June-end.
During the second phase (June-September 2010), random cloud seeding experiments will be carried out, using the aircraft equipped for seeding and the one containing the special equipment.
"Based on the properties of clouds, we will start the seeding programme across India. The seeding aircraft will spray hygroscopic particles (salts) that can broaden water droplets in clouds and hasten the onset of precipitation formation," said Kulkarni.
In the third phase (2011-12), scientists will measure and analyse the seeding impact.
"A dense network of automatic rain gauges will be installed in the experimental area to measure the rainfall. Rain water samples will be collected from the seeded and non-seeded clouds. The chemical analysis of rain water samples will be carried out to understand the effect of seeding on the precipitated water," he said.
"The experiment will give us an idea which areas are conducive for cloud-seeding and the amount of increase in rainfall after the experiment," he added.
Many other organisations, including the Indian Institute of Technology-Kanpur, the National Aerospace Laboratory, Bangalore, the Indian Air Force and the Indian Navy, are participating in the project.
China presently has the largest cloud seeding system in the world. It used cloud seeding in Beijing just before the 2008 Olympic Games in order to clear the air of pollution. In February 2009, China also used iodide sticks to artificially induce snowfall over Beijing after four months of drought.
A total of 24 countries currently practice weather modification operationally.
ARTIFICIAL RAINFALL
..[cloud seeding
INTRODUCTION
Artificial rainfall is also known as Cloud Seeding. Cloud seeding is a weather modification system that aims to boost precipitation or rain by introducing condensation nuclei such as salt or dry ice.
1st Stage
The first stage is Agitation. That is using chemicals to stimulate the air mass upwind of the target area to rise and form rain clouds. The chemicals used during this stage are calcium chloride, calcium carbide,
calcium oxide, a compound of salt and urea, or a compound of urea and ammonium nitrate. These compounds are capable of absorbing water vapor from the air mass, thus stimulating the condensation process.
2nd Stage
The second stage is called Building-up stage. Here the cloud mass is built up using chemicals such as kitchen salt, the T.1 formula, urea, ammonium nitrate, dry ice, and occasionally also calcium chloride to increase nuclei which also increase the density of the clouds.
3rd Stage
In the third stage of bombardment chemicals such as super-cool agents:
silver iodide and dry ice are used to reach the most unbalanced status which builds up large beads of water (Nuclei) and makes them fall down as raindrops. The process is called seeding.
SMIQBAL.
