The Water Cycle Flashcards
Facts?
Hydrosphere contains 1.4 sextillion litres of water
- Most is saline water in oceans.
- Less than 3% is freshwater
- 69% of freshwater is frozen in cryosphere
- 30% of freshwater is groundwater
- 0.3% of freshwater is in lakes or rivers
- 0.04% of freshwater is water vapour in atmosphere
What is the water cycle?
Water is continuously cycled between different stores. This creates a global hydrological cycle which is a closed system.
Different flows in the water cycle?
Evaporation
Condensation
Cloud formation and Precipitation
Cryospheric processes
Flow 1 - Evaporation
Liquid water changes state into a gas, becoming water vapour. Generally occurs by solar radiation.
Increases atmospheric store of water.
Magnitude of flow depends on location and season.
Flow 2 - Condensation
Water vapour changes state to become a liquid. Happens when our containing water vapour Cools to its dew point.
Water droplets remain in the atmosphere or transfer to another subsystem, store in the atmosphere will decrease.
Magnitude dependent on amount of water vapour in atmosphere and temperature.
Flow 3 - Cloud formation and Precipitation
Clouds form when air cools down, causing the water vapour in to condense into water droplets, gather as clouds then fall as precipitation.
Frontal Precipitation
Orographic Precipitation
Convection Precipitation
Cloud formation also requires cloud condensation nuclei, to give water a surface to condense on.
Will be seasonal and depend on location.
Flow 4 - Cryospheric processes
Accumulation and Ablation, change amount of water stored as ice in cryosphere.
Types of Precipitation?
Frontal - warm air meets cool air and warm air forced above cool air, cools down as it rises.
Orographic - warm air meets mountains, forced to rise and will cool.
Convection - sun heats up ground, moisture on ground evaporates, rises as column of warm airs, cools as it rises.
