Water and carbon cycles as natural systems:
Open systems – systems in which both water and energy are allowed to transfer across the
system boundary.
Closed systems – systems in which there may be a flow into or out of the systems (e.g.
sunlight) but no matter flow takes place across the system boundary.
INPUTS Added to the system
FLOWS Moves in or beyond the system
STORES Energy builds up and remains
OUTPUTS Mass or energy leaves the system.
The water cycle:
Biosphere Parts of the Earth’s system where living things are found.
Atmosphere The layers of gas between the Earth (liquid/gas/solid).
Hydrosphere Includes all the water on the Earth (liquid/gas/solid), ¾ of the Earth is
water.
Cryosphere Includes all parts of the Earth’s systems where it is cold enough for water
to freeze.
Lithosphere The outer most part of the Earth, including crust, and upper parts of the
mantle.
The global spheres change over time in many ways including:
Day – atmosphere (rain).
Season – Sea ice (melts in summer).
Year – Sea ice (fluctuates with melting and freezing).
Decade – (permafrost).
Century – sea level.
Millenia – Ice ages.
Processes driving change in magnitude of stores over time and space:
1. Climate change.
2. Temperature.
, Process Definition Heat energy used or The surrounding air
released? is …?
Evaporation Liquid becomes Used. Cooled
vapour.
Condensation Gas to liquid Released. Warmed
Sublimation Solid to gas Used Cooled
Deposition Gas to solid Released Warmed
Freezing Liquid to solid Released Warmed
Melting Solid to liquid Used Cooled
Cloud formation:
1. The atmosphere must be cooling in order for water vapour and aerosols (salt and
dust) to collide.
2. As atmosphere cools, more of the water vapour and aerosols collide and join
together. The cooler the atmosphere the less space there is so the particles become
more dense.
3. As more and more droplets join, they form clouds (“condensation”).
4. If the water droplets are below -30 degrees, it will fall as ice/hail. If the water
droplets are above -30 degrees, it will fall as rain. This depends on the height of the
cloud.
5. Clouds form when the air is saturated and cannot hold any more water
6. As the air rises, it will cool and reducing the temperature of the air decreases its
ability to hold water vapour to condensation occurs. At the dew point, the clouds
become too heavy for the atmosphere and gravity forces the water droplets to fall as
rain.
Types of rainfall:
Relief rainfall
1. prevailing winds bring moisture from the sea to the coast and the moisture is
forced up the mountain.
2. The air cools and condenses, forming cloud.
3. The air continues to be forced over mountains and drops moisture as relief rainfall.
4. Once over the mountain, air drops down the other side - warming as it drops. This
means it has a greater ability to carry water moisture and so there is little rainfall on
the other side of the mountain.
Frontal rainfall
1. Two air masses meet (one warm, one cold).
2. The less dense, warm air is forced to rise over denser colder air.
3. This causes warm air to cool and condense.
4. As the warm air is forced to rise further condensation occurs and rain is formed.
Open systems – systems in which both water and energy are allowed to transfer across the
system boundary.
Closed systems – systems in which there may be a flow into or out of the systems (e.g.
sunlight) but no matter flow takes place across the system boundary.
INPUTS Added to the system
FLOWS Moves in or beyond the system
STORES Energy builds up and remains
OUTPUTS Mass or energy leaves the system.
The water cycle:
Biosphere Parts of the Earth’s system where living things are found.
Atmosphere The layers of gas between the Earth (liquid/gas/solid).
Hydrosphere Includes all the water on the Earth (liquid/gas/solid), ¾ of the Earth is
water.
Cryosphere Includes all parts of the Earth’s systems where it is cold enough for water
to freeze.
Lithosphere The outer most part of the Earth, including crust, and upper parts of the
mantle.
The global spheres change over time in many ways including:
Day – atmosphere (rain).
Season – Sea ice (melts in summer).
Year – Sea ice (fluctuates with melting and freezing).
Decade – (permafrost).
Century – sea level.
Millenia – Ice ages.
Processes driving change in magnitude of stores over time and space:
1. Climate change.
2. Temperature.
, Process Definition Heat energy used or The surrounding air
released? is …?
Evaporation Liquid becomes Used. Cooled
vapour.
Condensation Gas to liquid Released. Warmed
Sublimation Solid to gas Used Cooled
Deposition Gas to solid Released Warmed
Freezing Liquid to solid Released Warmed
Melting Solid to liquid Used Cooled
Cloud formation:
1. The atmosphere must be cooling in order for water vapour and aerosols (salt and
dust) to collide.
2. As atmosphere cools, more of the water vapour and aerosols collide and join
together. The cooler the atmosphere the less space there is so the particles become
more dense.
3. As more and more droplets join, they form clouds (“condensation”).
4. If the water droplets are below -30 degrees, it will fall as ice/hail. If the water
droplets are above -30 degrees, it will fall as rain. This depends on the height of the
cloud.
5. Clouds form when the air is saturated and cannot hold any more water
6. As the air rises, it will cool and reducing the temperature of the air decreases its
ability to hold water vapour to condensation occurs. At the dew point, the clouds
become too heavy for the atmosphere and gravity forces the water droplets to fall as
rain.
Types of rainfall:
Relief rainfall
1. prevailing winds bring moisture from the sea to the coast and the moisture is
forced up the mountain.
2. The air cools and condenses, forming cloud.
3. The air continues to be forced over mountains and drops moisture as relief rainfall.
4. Once over the mountain, air drops down the other side - warming as it drops. This
means it has a greater ability to carry water moisture and so there is little rainfall on
the other side of the mountain.
Frontal rainfall
1. Two air masses meet (one warm, one cold).
2. The less dense, warm air is forced to rise over denser colder air.
3. This causes warm air to cool and condense.
4. As the warm air is forced to rise further condensation occurs and rain is formed.
