The sun and gravity profoundly influence the water cycle, driving its key processes and ensuring continuous water movement on Earth.
The Role of the Sun in the Water Cycle
The sun's energy is the primary driver of the water cycle. Here’s how:
- Evaporation: The sun's heat causes liquid water to evaporate, transforming it into water vapor. This occurs from bodies of water like oceans, lakes, and rivers.
- Evapotranspiration: Evapotranspiration is a crucial process where water moves into the atmosphere from both land surfaces and plants. This process is also powered by the sun.
The Role of Gravity in the Water Cycle
Gravity is essential for the downward movement of water:
- Precipitation: Gravity causes water to fall back to Earth in the form of rain, snow, and hail from clouds.
- Surface Runoff: Gravity causes water to flow downward on land, creating surface runoff that eventually returns water to bodies of water like rivers and oceans.
Sun and Gravity Working Together:
| Process | Influence of the Sun | Influence of Gravity |
|---|---|---|
| Evaporation | Provides energy to turn liquid water into vapor. | N/A |
| Transpiration | Powers the release of water vapor from plants. | N/A |
| Precipitation | N/A | Causes water to fall from the atmosphere. |
| Surface Runoff | N/A | Causes water to flow downhill. |
In summary, the sun's energy lifts water into the atmosphere, while gravity pulls it back down, creating a continuous cycle.
