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Artificial rain: Deliberately changing weather is interfering with nature - Geography Journalist Jeevan Sharma
Kathmandu. The history of artificial rainfall was first conceived in 1891 by Louis Gathman. He suggested injecting liquid carbon dioxide into clouds to induce precipitation. In the 1930s, the Bergeron-Findleisen process demonstrated in laboratory experiments that adding ice crystals to clouds could cool water vapor and turn water droplets into rain.
However, the first successful experiment was conducted by Vincent Schaefer in 1946 by producing ice crystals from dry ice.
Using this technique, the first artificial precipitation was made in New York on November 13, 1946, using cloud seeding from an airplane, resulting in snow.
History of artificial rainfall in India The Tamil Nadu government first used artificial rainfall in drought-prone areas in 1983.
After this, it was also adopted in Karnataka and Maharashtra in 2003 and 2004 respectively. Recently, artificial rainfall has been attempted in Rajasthan and Delhi.
• How is artificial rain produced?
In this age of science and technology, people have succeeded to a great extent in creating favorable conditions using technology. One of these is artificial rain. At present, artificial rainfall in low rainfall areas is discussed every year. The act of making rain by creating favorable conditions for rain in the clouds using technology and some chemicals is called artificial rain. It is also known as cloud seeding or cloud seeding. We will explore the process, limitations and challenges of artificial rainfall in detail.
• What is Artificial Rain?
Attempts are made to induce rain by spraying certain chemicals into the clouds and creating short-term changes in the weather. This process is called cloud seeding or cloud seeding. In this process, the moisture in the clouds turns into water droplets, which fall to the ground under the influence of gravity. Artificial precipitation requires sufficient moisture in the clouds. To better understand artificial rain, let's first understand how rain occurs naturally.
Rain occurs naturally when vapor particles in the atmosphere condense into water droplets or snow and fall to Earth. However, when nature cannot provide enough rain or problems such as drought, fire or lack of water arise due to lack of rain for a long time, artificial rain is tried with the help of science. This process is called artificial rain.
Artificial precipitation involves spraying chemicals—such as silver iodide, sodium chloride, or potassium iodide—into atmospheric clouds. These substances attract the vapor particles in the clouds and help them form larger water droplets. When those droplets become heavy enough, they fall to Earth as rain.
Artificial rain is often used for the following reasons:
o For drought and drought control – to supply water to save agricultural areas.
o For forest fire control – fire extinguishing aids.
o To reduce air pollution – to clean dust and smoke.
o To fill reservoirs – to generate electricity and secure water sources.
Artificial rain is an expensive, technically complex process that is not successful everywhere. Also, excessive use of chemicals can also have an environmental impact.
How is artificial rain produced?
Water on Earth's surface absorbs heat from sunlight and turns into water vapor. Water vapor is the gaseous form of water. Being lighter, water vapor rises against gravity. Clouds form when large amounts of water vapor condense. Water vapor in the air condenses into dust particles, pollutants, pollen and ice crystals at extremely low temperatures on their surfaces, forming water droplets. The conversion of water vapor into water droplets is called condensation. These drops, being heavy, fall to the ground under the influence of gravity, called rain.
In the troposphere, temperature decreases with height. The rate at which temperature decreases with height is called the lapse rate. It is usually 6.5 degrees Celsius per kilometer. Accordingly, at an altitude of about 6 to 7 km, the temperature is close to zero.
Rainwater either evaporates directly from the earth's surface or flows into the ocean through rivers and streams. From there, the process of evaporation begins again. This whole cycle is called water cycle.
Artificial precipitation requires a sufficient amount of moisture in the clouds. Without dew, artificial rain is impossible. To produce artificial precipitation, specific chemicals such as silver iodide, sodium chloride, solid CO2, or dry ice are sprayed onto moist clouds. This is done using spraying aircraft or modern drone equipment. These chemicals act like tiny ice crystals, attracting dew. This triggers the process of condensation. This process happens when a bottle of cold water is taken out of the freezer and left outside, the water vapor in the air around it condenses and forms droplets. Likewise, because of these cold chemicals, water vapor in clouds condenses into droplets and falls under the influence of gravity, which we call rain.
