Water droplets in clouds grow through a process of collision and coalescence.
Initial Growth: Turbulent Collisions
The initial growth of water droplets begins due to turbulent currents within the clouds. These currents cause tiny cloud droplets to collide with one another.
- These collisions are the starting point for droplet growth, as stated in the provided reference.
- When droplets collide, they can combine to form a larger droplet. This process is called coalescence.
Accelerated Growth: Falling Velocity
As droplets grow larger through repeated collisions, their fall velocity increases. This increased velocity plays a critical role in further growth:
- Larger, faster-falling droplets can collide with smaller, slower-falling droplets.
- This difference in fall speed increases the rate of collisions and allows for rapid growth.
Summary of Water Droplet Growth
| Stage | Mechanism | Effect on Droplet Size |
|---|---|---|
| Initial Collision | Turbulent currents cause collisions | Slight Increase |
| Coalescence | Combining of droplets upon collision | Size increase |
| Accelerated Growth | Larger droplets collide with smaller ones | Rapid Increase |
Conclusion
The process of water droplet growth involves turbulent mixing, collisions, and coalescence. The different fall velocities of droplets also contribute significantly to the increasing size of raindrops.
