2. Content
1. What is arti
fi
cial rain
2. Types of cloud
3. Worm cloud seeding
4. Cold cloud seeding
5. Cloud seeding types
6. Steps of cloud seeding by air
7. Ground based generator
8. Cloud seeding fl
ares
9. Why do we need arti
fi
cial rain
10. Countries using this TECH
11. What are the other uses
12. History
13. Pros and cons
14. Statistics
15. References
3. What is artificial rain?
• Weather modi
fi
cation depending on scienti c technology that
can improve cloud precipitation (rainfall) that aims to increase
water availability worldwide.
• Cloud seeding
4. Types of cloud seeding
Warm
cloud
seeding
(NaCl)
Cold
cloud
seeding
(AgI or
CaCl2)
5. Warm cloud seeding
• Using salts such as NaCl, CaCl2 , at temperatures not colder
than o° C producing rain.
• It is also called Hygroscopic seeding (tending to absorb)
• located in tropical region
6. Cold cloud seeding
• Using super cooling agents such as Agl, Dry ice at
temperatures colder than o°C which act as ice nuclei, thus
producing larger snow crystals.
• It is also called Glycogenic seeding
8. Steps of cloud seeding air based
• Using weather forecasting techniques
• Suitable clouds are identi
fi
ed
• Then the conditions is analysed - when suitable
• With the help of jet planes, the substance like silver oxide ,dry
ice , salt etc
• An airplane spraying the nucleating agents into the clouds
9. Ground based generator
Alternate technology that has been developed and successfully
applied in Indonesia (static weather modi cation technology
system)
13. What are the other uses
• Fog suppression
• Hail suppression
• Rainfall enhancement
• Snowpack enhancement
14. History
• In 1946, Schaefer conducted the
fi
rst true cloud seeding experiment by
aircraft. He dropped 6 pounds of crushed dry ice into a cloud in the
Adirondack Mountains of New York. Almost immediately, snow began to fall.
• Modern-day cloud seeding was launched in the lab of noted surface
scientist Irving Langmuir at General Electric in 1946. His colleagues Vincent
Schaefer and Bernard Vonnegut, brother of author Kurt, discovered that
silver iodide could transform supercooled water vapor into ice crystals at
temperatures of –10 to –5 °C
15. Pros
• Rain creation
• Boosting of the economy
• Weather regulation
• Makes dry places more liable
• Reduction of crop damage
• Variety of methods for practice
• Geographically oriented
16. cons
• Requires the use of potentially harmful chemicals
• Its not foolproof
• Its expensive
• Poses weather problems
• Dependence on atmospheric conditions
• Unknown impact of long
term exposure to cloud seeding
17. Statistics
• The e
ff
ectiveness is 20-30%
• It takes around 30-40 min
• Environmental Modi
fi
cation Techniques (ENMOD) controls the legal
frame work
• The rate is 24 cloud cost around $5000
• 30-35% percent in a clear atmosphere, and up to 10-15% in a
more humid atmosphere.