Artificial rain is not a new term in the age of artificial intelligence. Artificial rainfall is discussed as an alternative to control situations like floods, droughts, heat waves, storms, forest fires etc.
Due to the serious situation created by the increasing pollution in Mumbai, Navi Mumbai and Delhi, this issue is currently being discussed.
The pollution level in Delhi has been ‘severe’ for the past several days. Critical means Delhi’s air index is between 401 and 500. The air quality in Mumbai and Navi Mumbai is also deteriorating and on November 7 the air index reached around 167 and 225 respectively.
According to experts, when the ‘AQI’ or ‘Air Quality Index’ is between zero and 50, it is called ‘good’.
An index between 51 and 100 is considered ‘satisfactory’, an index between 101 and 200 is considered ‘moderate’, an index between 201 and 300 is considered ‘poor’, an index between 301 and 400 is ‘very poor’. An index of 401 and 500 is considered ‘very serious’.
The Delhi government has made several announcements one after the other to tackle and control the severe levels of pollution.
Delhi’s Environment Minister Gopal Rai has told what steps the government is going to take to deal with pollution. Of all the measures suggested by the government, the suggestion of artificial rain through cloud seeding is the most talked about.
Delhi government minister Saurabh Bhardwaj said, “Delhi’s geographical situation is such that during this time of the year many cities in North India, including Delhi, suffer from pollution. It can be treated with artificial rain. Yesterday we had a meeting with experts from IIT Kanpur. If we get permission from the Supreme Court , so the government needs to implement this as soon as possible. If this experiment is successful, we will have a very effective technology for the whole of North India, not just Delhi.”
Testing artificial rain in Mumbai too
After Delhi, the state government and the municipal corporation have decided to take various measures to curb the pollution in Mumbai and its surroundings.
Mumbai Municipal Commissioner Iqbalsingh Chahal informed in a press conference held on Thursday that if the ‘cloud seeding’ in Delhi is successful, it will be considered in Mumbai as well.
Along with this, claiming that the dust is spreading due to the cars entering the city, the municipality is going to install ‘water jet spray machines’ at the entrances to wash the wheels of the cars.
If the pollution persists again, IIT experts have suggested measures like banning heavy vehicles, taking action against vehicles emitting smoke, allowing vehicles to be driven on the roads in an even-odd manner.
Even in Mumbai, Chief Minister Eknash Shinde has appealed to school students to celebrate Diwali without crackers, while Guardian Minister of Mumbai Deepak Kesarkar has requested the citizens of Mumbai to celebrate Deepotsav with minimum or possibly no crackers during Diwali.
What is artificial rain, how is it delivered and how effective is it in combating pollution, as administrations discuss artificial rainfall trials in cities like Delhi and Mumbai? Such questions are raised.
To find out the answers to all these questions, we spoke to SN Tripathi, Professor of Civil Engineering at IIT Kanpur. The information below is based on this discussion.
What is Artificial Rain?
When clouds form naturally in the atmosphere and those clouds produce rain, it is called natural rain.
But it often happens that clouds are formed but due to some imperfect process in them they cannot produce rain. Or even if it rains, it stays only in the clouds and does not reach the ground.
In that case, when rain is given according to this cloud according to a special technique, it is called artificial rain. This technique is called ‘cloud seeding’.
What is ‘cloud seeding’ technology?
The term ‘cloud seeding’ is derived from two words ‘cloud’ and ‘seeding’.
‘Cloud’ means cloud and ‘seeding’ means sowing.
It may sound strange but in simple words the process of sowing ‘rain’ seeds in the clouds is called ‘cloud seeding’.
One thing that can be noted here is that substances like silver iodide, potassium chloride and sodium chloride are used as ‘seeds’.
These chemicals are sprayed in the clouds with the help of airplanes.
The sprayed material diffuses into the cloud and freezes the water droplets in the cloud. By absorbing the vapor in the cloud, the size of the droplet increases and rain starts falling from the cloud. Silver iodide particles are sprayed onto the cloud when it lacks the nuclei necessary for ice formation in a cold cloud.
These particles are like ice crystals. Ice cubes form rapidly and grow large enough to shoot down toward the ground. In this way rain can be made from a cloud that is incapable of producing rain.
Cloud seeding has a long history
American scientist Vincent J. Shafer invented ‘cloud seeding’.
Its seeds can be found in the 1940s, especially in the United States during that time.
Professor S.N. Tripathi explains, “You cannot plant a seed where there are no clouds. First of all we have to see if there are clouds, if so how high they are, what are their characteristics and the atmosphere. Then, with the help of estimation or measurement, the amount of water in the cloud is found out. A special chemical (a mixture of salts or salts) is then sprayed into the clouds at the right place. This chemical accelerates the microscopic physical processes of clouds (ie, raindrops, snowflakes). Then those snowflakes fall to the ground as rain.
There is also a technique to shock the clouds with lightning, which can be used to cause rain. In this, with the help of drone technology, lightning is given to the clouds.
The UAE used this technology to produce artificial rain in 2021.
When is artificial rain needed?
Artificial rainfall is generally used to deal with drought and flood situations.
In addition, it is also used to reduce severe forest fires, unbearable heat or heat waves, storms and pollution.
Artificial rain falls regularly in Israel because there is very little natural rain. Nowadays, artificial rainfall is also used in research and operational programs by the United Arab Emirates.
How effective is it for pollution control?
Israel regularly receives artificial rainfall because there is very little natural rainfall. Nowadays, artificial rainfall is also used in research and operational programs by the United Arab Emirates.
China carried out ‘cloud seeding’ during the 2008 Beijing Olympics with the help of aircraft and ground guns. After that they helped a lot in pollution control.
If we think about India, we have done ‘cloud seeding’ before. But so far this has been done with the help of foreign aircraft, foreign seeding tools and foreign scientists and engineers.
This is the first time that IIT Kanpur has developed its own salt (dust) i.e. chemical, the aircraft also belongs to IIT Kanpur and we have developed our own seeding equipment. So if it is used in Delhi it will be completely indigenous.
As for its effectiveness, it depends on its seeding.
If sown properly, this technology will be effective in all cases as pollution can be automatically controlled when large areas receive rain.
When was it first used?
Currently many countries use it.
In 2017, the United Nations Meteorological Organization estimated that more than 50 countries had tried cloud seeding so far.
These include Australia, Japan, Ethiopia, Zimbabwe, China, America and Russia.
India has also used it. China, which suffers from pollution like India, also uses it the most.
In 2008, China used cloud seeding technology for the first time before the Summer Olympic Games held in Beijing.
India used it for the first time in 1984. Then there was a severe drought in Tamil Nadu. Then the Tamil Nadu government took help of cloud seeding technology during 1984-87, 1993-94.
The Karnataka government also experimented with cloud seeding in 2003 and 2004. In the same year, Maharashtra government made this attempt.