GLOBAL WATER CYCLE Flashcards
How deep would water, uniformly spread, cover the earth
3000M / 3km
in what forms is the water on earth
97% is salt water
2% is ice
0.7% is groundwater
0.01% is surface freshwater
how much rain would we have if all of the water in the atmosphere condensed
0.025m / 2.5cm
where does the water go when its evaporated from the ocean in the hydrological cycle
80% back to ocean
20% transported to land - some run off back to ocean, most back to atmosphere by plant evapotranspiration
what is relative humidity
The amount of water in the air relative to the amount of water it could hold
100% humidity = condensation
what temp air holds more water
warm
What conditions are necessary in order to make rain
- Warm wet air
- Some way to cool the air
name of the front that rain forms
OCCLUDED FRONT - warm air meets cold air
what side of a mountain gets a lot of precipitation
- windward - wind blows warm wet from the ocean up the mountain - air cools and makes rain
- leeward side - air goes down the mountain and warms again (Rain-Shadow Deserts)
what are intertropical convergence zones
where global air masses converge and rise
- Rising air, low pressure, rain
why do subtropical desserts form
they lie beneath the portion of an atmospheric circulation cell (Hadley cell) where dry air descends and warms - rain clouds rarely form
- Falling air, high pressure, dessert
how do coastal deserts form
Cold ocean currents cool and moisten the air along the coast - This air is too dense to rise and produce rain clouds
- Atacama Desert is the driest place on Earth - While clouds form there, they don’t produce rain
where in the globe can we find High precipitation where air masses rise
at the equator
~ 60°N & ~ 60°S (polar fronts)
windward slope of a mountain
where in the globe can we find low precipitation where air masses descend
at the poles
~ 30° N and 30° S latitudes (horse latitudes)
leeward of a mountain
land adjacent to cold ocean currents
how to calculate residence time
vol / flow rate
HOW LONG DOES THE AVERAGE WATER MOLECULE STAY IN THE ATMOS (residence time)
0.026 years / 9 days
HOW LONG DOES THE AVERAGE WATER DROP
STAY IN A RIVER
0.034 years / 12 days
which part of the atmosphere do we find weather that controls precipitation
trophosphere
