1. “Don’t make me read, make me understand “
Full of ingredients to make your child a genius.
“Don’t make me read, make me understand “

2. Precipitation

3. General concept
There are several forces acting on a water droplet or ice crystal in a cloud
Winds
Atmospheric stability
Gravity
Drag (friction)
When a droplet reaches a certain critical mass the force of gravity will exceed the other forces and precipitation will fal
Rain drops are 100X larger than cloud droplets

4. Formation of precipitation
Condensation and deposition
Collision and coalescence
The Bergeron process
Warm air
Cold air

5. Condensation and deposition
As long as the rate of condensation exceeds the rate of evaporation water will be deposited and accumulate on condensation nuclei
Droplets grow very slowly
Rarely produces rain drops

6. Collision and coalescence
As water droplets fall through a cloud, the larger droplets fall faster than the smaller ones, thus they collide
If the droplets coalesce a larger drop is formed
If it gets big enough rain will fall

7. Collision efficiency
A drop must be larger than the other drops to be an efficient collider If the drop is too big it will be less efficient, because it creates high pressure that pushes small drops out of the way

8. Cold and cool clouds Cold < 00C throughout Cool Part is < 00C

9. Types of precipitation
snow
rain
sleet
graupel
hail
freezing rain

10. Rain
Can originate as liquid drops or ice. Ice melts as it falls through warmer air Shape of rain drops

11. Snow
Ice crystals grow in a cloud. Variety of shapes depending on temperature

12. Graupel Ice crystals grow by riming Contain air pockets
Has a spongy texture

13. Sleet
Ice crystals melt as they fall through warn air aloft. Then water drops freeze as they fall through cold air below and hit the surface as ice pellets

14. Freezing Rain
Ice crystals fall through warm air aloft and melt, Then liquid water falls through air at nearly 00C and freezes when it hits the cold (00C)ground

15. Hail Strong updrafts in a cloud force ice particles upward
As they move up and down in the cloud hail stones accumulate layers of ice
Eventually they get too heavy and fall

16. Distribution of precipitation in the US
Why?

17. Distribution of snowfall in the US
Why?

18. Any questions?

19. Have a great day!

20. Thanks
Submitted by
Ashutosh
Kendriya Vidhyalaya

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22. “Don’t make me read, make me understand “
Full of ingredients to make your child a genius.
“Don’t make me read, make me understand “