1A - A Closed System
The global hydrological cycle's operation as a closed system (inputs, outputs, stores and flows) driven by solar energy and gravitational potential energy.
A closed system
The global hydrological cycle is the circulation of water around the earth. It is a closed system of linked processes so there are no external inputs or outputs. For this reason, the amount of global water is finite and constant. The only thing that does change is the state in which the water exists (liquid, vapour, ice). The proportions of global water held in each state vary over time with changes in climate.
Driven by Solar Energy and Gravitational Potential Energy
The power that drives the global hydrological cycle comes from two sources:
The global hydrological cycle is the circulation of water around the earth. It is a closed system of linked processes so there are no external inputs or outputs. For this reason, the amount of global water is finite and constant. The only thing that does change is the state in which the water exists (liquid, vapour, ice). The proportions of global water held in each state vary over time with changes in climate.
Driven by Solar Energy and Gravitational Potential Energy
The power that drives the global hydrological cycle comes from two sources:
- Solar energy: in the form of heat
- Gravitational potential energy: causes rivers to flow downhill and precipitation to fall to the ground.