Water and carbon cycles Flashcards
What is a model
An idealised representation of reality
What is a system
A set of inter-related components or events working together
What does a system typically consist of
inputs, stores and outputs, with a series of flows or connections between them
What are the different types of systems
close
open
isolated
sub systems
What is an isolated system
there are no interactions with anything outside the system boundaries - there is no input or output of energy or matter
What is an open system
Both energy and matter transfer freely into and out of the system
What is a closed system
There is a transfer of energy into and beyond the system but no transfer of matter
What is a sub-system
A component of a larger system. The earth system has 5 sub systems, each of which is an open system with interrelationships between them.
What is dynamic equilibrium
Where there is a balance between inputs and outputs. For example, Wave currents remove and replace sand on a shoreline but the beach apparently stays the same
What are the 5 sub-systems of the earth
- Lithosphere
- Hydrosphere
- Biosphere
- Cryosphere
- Atmosphere
When does feedback occur
When a change in one part of the system causes a change in another part.
What are the 2 types of feedback called
Negative feedback and positive feedback
What is negative feedback
A feedback which keeps a system in its original condition
What is positive feedback
A feedback where there is a progressively greater change from the original condition of the system
What do positive feedback mechanisms do
amplify the change in inputs or outputs
What does it mean when positive feedback mechanisms amplify change to the inputs or outputs
Means the system responds by increasing the effects of the change, moving the system even further from it’s previous state
What do negative feedback mechanisms do
counteract the changes in the inputs and outputs
What happens when negative feedback mechanisms counteract change to the inputs or outputs
Means that the system responds by decreasing the effects of the change, keeping the system closer to it’s private state
What is an example of positive feedback
- Temperature rises
- Ice covering cold parts of earth melts due to higher temperatures
- Less ice cover means less of the sun’s energy is reflected
- Less of sun’s energy being reflected means more is absorbed by the earth
What is an example of negative feedback
- Large amounts of C02 emitted
- CO2 in atmosphere increases
- Extra C02 cause plants to increase growth
- Plants remove and store more CO2 from atmosphere
- Amount of CO2 in atmosphere reduces
What are the 4 vital cycles that affect the earths sub-systems
- The carbon cycle - The nitrogen cycle
- The water cycle - The oxygen cycle
What are both the carbon and water cycles under pressure from
- ) An increasing population
2. ) Climate change
How much of the earths fresh water is frozen in cryosphere
69%
How much of the earths freshwater is stored in water sealed underneath the lithosphere ( groundwater)
30%
How much of the earths freshwater is stored on the earths surfaces in lakes and rivers etc ( Liquid freshwater)
0.3%
How much of the earths fresh water is stored as water vapour in the atmosphere
0.04%
How much water is contained in the hydrosphere
1.4 sextillion litres of water
How much water within the lithosphere is fresh and what is the water that is not freshwater called
Less than 3% of 1.4 sextillion litres is freshwater and most of the rest is saline water (salty)
What are ways water must be more accessible for humans
physically and economically
When water condenses and freezes what must happen to it’s energy
It loses energy
When water boils or melts, what happens to it’s energy
gains energy
What is the latent heat of fusion
Melting - The substance changes from a solid to a liquid - extra energy needed
Freezing - The substance changes from a liquid to a solid - loss of energy
What is the latent heat of vaporisation
Vaporisation - The substance changes from a liquid into a vapour - extra energy needed
Condensation - The substance changes from a vapour into a liquid - loss of energy
What is the latent heat of sublimation
Sublimation - The substance has a 2 phase change ( in this case from ice to gas) - extra energy needed
Deposition - The substance has a 2 phase change and loses energy ( gas to ice in deposition)
What are the 4 types of water stores
- Atmospheric
- Cryospheric
- Terrestrial
- Oceanic
What is evaporation the process of
turning a liquid into a gas
How does evaporation occur
When energy from the sun hits the surface of the water/land and causes liquid to change from liquid to a gas
What do the rates of evaporation depend on
- Amount of solar energy
- Availability of water
- Humidity of the air - The more humid the air, the closer to saturation point the air is, so less evaporation will occur
- Temperature of the air - Warmer air can hold more water then cold air
What is relative humidity
The amount of water vapour in the air at any given temperature compared to how much the air could possibly hold that temperature.
What happens if the air has 100% relative humidity
Said to be saturated, therefore holds as much water vapour as it can give the temperature
What is absolute humidity
The mass of water vapour in an air mass measured in grams per cubic metre (g/m3)
True or False - Warmer air can hold more water vapour than colder air.
True
What is condensation
The conversion of a vapour or gas into a liquid
When does condensation occur
- When air is cooled
- When there is a fall in pressure
What happens if air cools or there is a fall in pressure
It is able to hold less water vapour
What is the dew point
The temperature in which water vapour in the air turns into liquid water