CLOUD SEEDING / ARTIFICIAL RAIN

Why in news…

India’s first drone cloud seeding operation in Ramgarh near Jaipur was called off due technical slags and will be carried out within a month.
Project leading company -GenXAI.

Cloud Seeding…

Cloud seeding is a weather modification technique in which certain substances are introduced into clouds to encourage precipitation— in the form of rain, snow, or hail suppression.
Substances used-silver iodide, potassium iodide, dry ice (solid Co₂),liquid propane etc.
It works on the principle of enhancing the cloud’s natural microphysical processes, making water droplets or ice crystals grow large enough to fall to the ground.

How Cloud Seeding Works…

For rain to form naturally, tiny water droplets in clouds must collide and combine until they are heavy enough to fall. However, in many clouds — especially in dry or cold conditions — this process is slow or incomplete.
Cloud seeding accelerates this process by introducing “nuclei” (particles around which water vapor can condense or freeze).

Static Cloud Seeding:

This method involves introducing ice nuclei, such as silver iodide or dry ice, into cold clouds that have supercooled liquid water droplets.
The ice nuclei can trigger the formation of ice crystals or snowflakes, which can grow at the expense of the liquid droplets and fall as precipitation.

Dynamic Cloud Seeding:

Dynamic cloud seeding is a method of inducing rain by boosting vertical air currents. The process is considered more complex than static cloud seeding because it depends on a sequence of events working properly.

Hygroscopic Cloud Seeding:

This method involves spraying fine particles of hygroscopic materials, such as salts through flares or explosives into the base of warm clouds.
The particles can act as cloud condensation nuclei and increase the number and size of the cloud droplets, which can enhance the reflectivity and stability of the clouds.

Methods of Delivery…

Aircraft-Based: Planes fly into clouds and release seeding agents directly.
Ground-Based Generators: Burn compounds that rise with air currents into the clouds.
Rocket or Drone Delivery: Emerging technology for targeted and rapid seeding.

Advantages….

Drought Relief – Can induce rainfall in water-scarce regions, replenishing rivers, reservoirs, and groundwater.
Agricultural Support – Ensures irrigation water, reducing crop loss during weak monsoons.
Snowpack Enhancement – In cold regions, increases snow accumulation in mountains for hydropower and summer water supply.
Hail Suppression – Can reduce hailstone size, preventing damage to crops, vehicles, and property.
Forest Fire Control – Artificial rain can help extinguish or limit the spread of wildfires.
Water Resource Management – Supports planned water distribution in arid and semi-arid regions.
Economic Benefits – Protects agriculture and industries dependent on water, and supports tourism like ski resorts.
Climate Adaptation – Offers partial relief in regions affected by erratic rainfall due to climate change.

Challenges /Limitations….

Weather Dependency – Works only if suitable clouds are already present; cannot create rain from clear skies.
Uncertain Success Rates – Effectiveness varies depending on temperature, humidity, and cloud type.
High Costs – Requires aircraft, equipment and chemicals, making large-scale operations expensive.
Environmental Concerns – Long-term effects of silver iodide and other chemicals on soil, water, and ecosystems are debated.
Short-Term Relief – Provides temporary solutions, not a substitute for long-term water conservation strategies.
Ethical & Political Issues – Altering rainfall in one region could reduce it in another, leading to disputes.
Possible Unintended Effects – May impact local weather patterns or disrupt ecosystems.
Technical Limitations – Needs precise timing and expertise; wrong conditions can waste resources.

Related to: Environmental issues and climate change.