Cloud seeding is an artificial way of inducing moisture in the clouds to cause rainfall. It is a form of weather modification. Just like a farmer sowing seeds in the field, which later grow to crops, in cloud seeding the clouds are filled with ‘seeds’ to later fall as rain. The seeds in this case are nothing but the silver iodide, potassium iodide and dry ice.
To make rain, the clouds are showered with these ice crystals through airplanes or flares. The moisture in the clouds condenses around the ice crystals and become too heavy to stay afloat. So, these droplets fall as rain.
Condition Required For Cloud Seeding
Right atmospheric conditions with plenty of clouds that are capable of rain is required for cloud seeding. We cannot go and seed the clear skies. Clouds form from the condensation of invisible water vapor on nuclei from dust, pollen and salt from ocean spray. Cloud seeding increases the number of these available nuclei. Raindrops or ice crystals might not form without these added nuclei.
Effective cloud seeding is only possible in the presence of clouds that are capable of producing rain
Types Of Cloud Seeding
Advantages of Cloud Seeding
- Creates rain
- It does not just make rain, it also regulates water vapor that in turn prevent damages bought by destructive hails and storms
- It saves dry place from drought
Disadvantages of Cloud Seeding
- It uses chemicals which can harm the environment especially plants and animals. Though silver iodine is not currently known to be harmful to our health today, but it might change in the future as more research is done on that.
- The technique is mostly used on clouds that already show early signs of rainfall, so it is not known if it actually causes rain.
- Since it modifies the weather it might change climatic pattern.
- It is very expensive.
However, the complete effect of cloud seeding on the environment as a whole is not fully known yet.
Interesting Facts About Cloud Seeding
- Vincent J.Schaefer invented cloud seeding.
- Cloud seeding was used in the Vietnam War. The Department of Defense seeded clouds to extend the monsoon season along the Ho Chi Minh Trail during Operation Popeye (1967–72). The goal of the program was to deny the use of this major supply route by flooding it.
- The largest cloud seeding system in the world is China. China creates 55 billion tons of artificial rain a year and it plans to quintuple that
- China used cloud seeding in Beijing just before 2008 Olympics with the aim of clearing air pollution.
- In the United States, cloud seeding is used to increase precipitation in areas experiencing drought, to reduce the size of hailstones that form in thunderstorms, and to reduce the amount of fog in and around airports.
- In India cloud seeding has been used by the Government of Tamil Nadu and Karnataka to induce rainfall in areas affected by drought.
- Recent cloud seeding by Karnataka government
