CLOUD SEEDING

About: 

• Cloud seeding is a common term for one form of weather modification. It is used for a variety of reasons, including - 
  • increasing the amount of rainfall produced from clouds, 
    
    
  • reducing hail from thunderstorms, and 
    
    
  • eliminating fog that reduces visibility at busy airports. 
    
    
  
  
  
• Modern cloud seeding dates back to the late 1940's, springing from a discovery at the General Electric (GE) labs in Schenectady, New York in 1946. 
  
  
• How does cloud seeding work? 
  • Cloud seeding does not create new clouds. 
    
    
  • It increases the amount of rainfall by 10-15% from existing clouds by adding tiny particles called ice nuclei to the clouds. Inside the seeded clouds, water vapour freezes onto the particles. These heavier frozen particles fall towards the ground as rain. 
    
    
  • Cloud seeding materials are released via ground-based and/or airborne systems. 
    
    
  • The most common cloud seeding materials are silver iodide and dry ice. 
    
    
  
  
  
• Why is cloud seeding so attractive? 
  • Cloud seeding is a highly portable and flexible technology. It does not require construction of large, permanent and costly structures, such as dams or water conveyance systems.  
    
    
  • Projects can be mobilized quickly and operations can be regulated. 
    
    
  • Studies have indicated no significant environmental impacts. 
    
    
  • Further, the benefit/cost ratios associated with most cloud seeding projects are typically very favourable.