News: Amid surging pollution levels, the Delhi government, in collaboration with the Indian Institute of Technology, Kanpur conducted two cloud-seeding trials to induce rain.
About Cloud Seeding
- Cloud seeding is a weather modification technique designed to induce rainfall or snowfall by introducing particles into clouds that act as condensation or ice nuclei, encouraging precipitation.
- The practice originated in the 1940s.
- Objective: It includes enhancing water supply, boosting crop yields, and reducing hail or storm damage in vulnerable areas.
- Working mechanism: The process relies on introducing particles that trigger water or ice droplet formation within clouds, eventually leading to rain or snow.
- Methods of dispersal: Aircraft, rockets, drones, or ground-based generators.
- Common Seeding Agents:
- Silver iodide, potassium iodide, dry ice, urea, and table salt are most widely used.
- Natural substances such as pollen, dust, and certain bacteria (e.g., Pseudomonas) can also act as nucleation surfaces.
- Hygroscopic materials like table salt, calcium chloride, and urea attract moisture, further promoting condensation.
- Advanced Methods: Recent experiments use laser pulses or electrical charges to combine water molecules, alter latent heat in clouds, and strengthen updrafts to enhance precipitation potential.
- Conditions Required for Cloud Seeding:
- Adequate cloud cover and depth are essential.
- The process works only with specific clouds, mainly hygroscopic or warm-rain clouds that already contain enough moisture.
- Advantages
- Increases Rain or Snow: Can potentially boost precipitation, benefiting agriculture, reservoirs, and drought-prone regions.
- Mitigates Harsh Weather: May lessen hail or storm damage in sensitive areas.
- Relatively Cost-Effective: Compared to large-scale water management projects, cloud seeding is less expensive to implement.
- Disadvantages
- Uncertain Effectiveness: Success depends heavily on existing atmospheric conditions and the presence of suitable clouds — outcomes are inconsistent.
- Environmental Risks: Silver compounds are toxic to aquatic life and excess sodium can degrade soil and inhibit plant growth.
- Weather Disruption: Artificially altering rainfall in one area may unintentionally affect weather patterns elsewhere, raising ecological and ethical concerns.
