MD Jahedul Islam

The process of producing rain from artificially created clouds in the sky is called cloud seeding. Artificial precipitation does not mean rain from artificially created clouds. Artificial rainfall is to force the unfavorable rain clouds in the sky to fall to the ground as rain. In fact artificial precipitation is a process by which precipitation is induced by artificially impregnating a particular type of cloud. Hence it is also called 'artificial transformation' of clouds. Cloud seeding (artificial precipitation) is the process of forcing rain through scientific manipulation of nature. On the other hand it is also known as "Cloud Seeding". In this case the first step is to create a cloud.

In the second step, this cloud has to be condensed and brought to a condition suitable for precipitation. In the third and last step rain is poured. However artificial precipitation is usually caused by turning clouds floating in the sky into water droplets. The principle of rain is the condensation of clouds. This process usually occurs naturally. Rainfall is completely natural. Naturally the sea, rivers or reservoir water evaporates due to the intense heat of the sun. Then these water vapors become clouds by mixing with numerous dust particles floating in the air. When these clouds floating in the troposphere become heavy to condense over time they fall to the surface as raindrops under the pull of Earth's gravity. Now if the clouds in this troposphere can be artificially condensed ahead of time.Then rain will start immediately. This is essentially what 'cloud seeding' does. Cloud seeding is the scattering of substances into the air, literally acting as cloud condensation or ice nuclei. Cloud seeding technology uses very common chemicals like dry ice, solid carbon dioxide, silver iodide, potassium iodide etc. Besides liquid propane gas is also used in this technology. This gas is capable of forming ice crystals at higher temperatures than silver iodide.

This causes the cloud to condense rapidly and reach a falling state. However, this technology has now increased the use of sodium chloride or table salt as it has proven to be much cheaper and quite effective. During cloud seeding, the temperature inside the cloud drops from 7°C to 20°C. At that time there is a danger of snowfall. So chemicals like silver iodide are used to get rid of such situations. Cloud seeding material is spread around the cloud by aircraft or rockets. As the aircraft moves through the clouds, silver iodide is also dispersed. Tiny crystalline grains of this chemical essentially act as cloud seeds.

The water vapor floating in these grains collects the water particles and turns into large droplets. For this, the cloud must first be created. In the second stage, these clouds have to be condensed and brought to the conditions suitable for precipitation. Condensed clouds once gain weight and fall as rain under the pull of gravity. However, artificial rain is usually caused by turning the clouds floating in the sky into water droplets. As a result artificial rainfall occurs. Artificial snow is produced along with rain using the same technology. Currently, silver iodide is the most effective and popular method for cloud seeding. Prolonged drought conditions have exacerbated the current century's water crisis. About 45% of the world's population suffers from severe water stress and lacks sufficient water for irrigation. In the next 20-25 years, there is a great possibility that all the countries of the world will suffer from acute water crisis. In such a situation, artificial rainfall is used to solve acute water problems. Technology is moving and dynamic. Technology never stands still. Day by day there is great development. Again the invention of a completely new technology breaks all previous ideas. Cloud seeding technology is still quite expensive. Scientists are currently researching to make the process happen with low cost laser technology.

Modern research is underway on cloud seeding using laser beams instead of airplanes or rockets. This new use of laser beams if discovered then it will play an important role in making artificial precipitation technology simple and affordable. Artificial rainfall is very necessary for regions in rainless and desert regions as well as in places where groundwater is saline. All those places are continuously monitored for artificial rainfall. A cloud seeding operation is initiated when a cloud capable of producing precipitation is found. Large-scale research to increase rainfall through cloud seeding, development of cloud seeding technology, construction of artificial lakes and dams for rainwater harvesting are essential. Fresh water is one of the main ingredients for the survival of humans and countless animals. Its only natural source is rainfall. But no one has control over this rain. It is also not always expected that the rains will fall in time according to the needs of the animals. Cloud seeding has proven successful in short-term or immediate needs. However artificial precipitation generated by this method is of little use in the long-term.

Besides, excessive cloud seeding can disrupt the natural balance of the environment. The chemicals used in it can also cause damage to health. The method of cloud seeding is not very complicated. Precipitation is caused by spraying chemicals on the clouds that are unsuitable for rain in the sky. Currently many countries are using cloud seeding technology in their rainfed crop production. The importance of using cloud seeding technology in agriculture is great. Cloud seeding technology has been playing an important role in protecting mainly rain-fed crops by causing artificial rainfall. With the increase in global warming the temperature of the earth's surface is also increasing proportionally. So other countries of the world depend on this technology to prevent desertification.

Meanwhile the use of cloud seeding technology plays an important role in hot countries and countries with severe weather. Using artificial rainfall technology is very effective in dealing with natural calamities like heavy rains, floods, cyclones and hurricanes. Not only dealing with natural disasters. Different countries of the world have shown the ability to produce more crops by using this technology of more rainfall. By using their intelligence, judgment and analysis, intelligence and practical skills, people are constantly advancing towards the use of modern technology to gradually control the adverse conditions of nature. Every action has an equal and opposite reaction. Artificial rainfall in one place has its effect in another place.

That is, there will be a severe lack of rain in other areas. On the one hand, the amount of water vapor in the air is reduced by precipitating precipitation through additional cloud seeding. On the other hand, as a row of cold clouds enters the sky from one country to another country the row of cold clouds from that country is exhausted. As a result artificial rainfall in one country is affecting another country. In addition to this, the climate of other countries is having a harmful effect. On the other hand excessive use of silver iodide pollutes soil quality.

As a result, there will be adverse effects on flora and fauna as well as ecosystems. So it is essential to conduct this technology operation very carefully and cautiouslySince the beginning of civilization, people have tried to establish their control over nature. The result of nature's rule has ever been a blessing. On the other hand it has sometimes caused extreme disasters. However at the speed at which science and technology are advancing, it can be assumed that in the future, human control over the basic structures of nature will increase day by day.

The writer is a ICT Cell, Jagannath University.