1c. The carbon and water cycles have distinctive processes and pathways that operate within them Flashcards
What is the water balance?
A method for understanding the flows of water cycling through a system
Equation for the water balance?
Precipitation = evaporation + streamflow +/- storage
P = E + Q +/- S
What are the main flows in the water cycle?
Evaporation
Transpiration
Condensation (+ cloud formation)
Precipitation
Interception
Ablation
Run-off
Infiltration
Percolation
Throughflow
Groundwater flow
What is evaporation?
- Process of water changing from a liquid to a water vapour
- Energy itself does not heat the water, but transfers into latent heat (the heat required to cause a change in state, without change of temperature), this is then released when condensation occurs
What is transpiration?
- Transfer of water vapour from vegetation to the atmosphere
- Occurs mostly via stomata
- 10% of atmospheric water originates from transpiration
What is condensation?
- Involves water vapour returning to a liquid state
- When water vapour reaches dew-point (temperature when the air becomes saturated) water droplets and clouds appear
What are the three main types of cloud?
- Cumuliform clouds
- Stratiform clouds
- Cirrus clouds
What are cumuliform clouds?
- Have flat bases and considerable vertical development
- Most often form through convection
What are stratiform clouds?
- Layer-type clouds
- Most often form through advection
What are cirrus clouds?
- Wispy clouds that do not produce precipitation
- Form at a high altitude and consist of tiny ice crystals
What are the types of cloud formation (and rainfall)?
Convectional
Relief
Frontal
Advection (not a type of rainfall)
What is convectional formation?
- Air is warmed by contact with the ground or sea surface, subsequently rises through the atmosphere
- As the air rises and pressure falls the air cools via adiabatic expansion, forming clouds
What is relief formation?
Air masses rise as they cross a mountain barrier or as turbulence forces their ascent
What is frontal formation?
- Warm and cool air meet
- Warm air forced upwards, then cools to form clouds
What is advectional formation?
Air masses move horizontally across a relatively cooler surface
What is environmental lapse rate (ELR)?
- Vertical temperature profile of the lower atmosphere at any given time
- On average temperature falls by 6.5 degrees celsius for every kilometre of height gained
What is dry adiabatic lapse rate (DALR)?
- Rate at which a parcel of dry air (less than 100% humidity so that condensation is not taking place) cools
- Cooling, caused by adiabatic expansion, is approximately 10 degrees celsius per kilometre