Chapter 12- Air Masses And Weather (water In The Atmosphere, Clouds and Rainfall) Flashcards
What is the water cycle?
The process by which water moves between land, sea and atmosphere.
What is the function of the water cycle?
To clean and renew the water
What are the four stages of the water cycle?
Evaporation
Condensation
Precipitation
Run-off
Explain the process of evaporation.
The heat of the sun changes water into water vapour
The water vapour rises
Explain the process of condensation.
As water vapour rises it cools to form clouds (tiny droplets)
Explain the prices of precipitation.
Wind blows the cloud over land
The clouds cool further
Rain forms and falls
(Precipitation-rain, snow or hail)
Explain the process of run-off.
Some water forms rivers and flows back to the sea
Some soaks into the land and goes back to the sea
Define water vapour.
Moisture in the form of gas in the air
What is relative humidity?
The percentage of water vapour in the air
-the actual website after content of the air as a percentage of the full amount of water the air could hold at a given temperature
How are cloud formed?
When water vapour is condensed into tiny droplets of water or ice crystals.
What are clouds?
Visible collections of water droplets or ice crystals
Name 3 types of cloud.
Cirrus
Cumulus
Stratus
State 3 facts about cirrus clouds
Wispy
High altitude
Indicate fair weather
State 3 facts about cumulus clouds
Woolly
Sometimes bring rain
Medium altitude
State 3 facts about stratus clouds
Dark layers of cloud
Bring rain or drizzle
Low altitude
Name 3 types of rainfall
Relief
Cyclonic
Conventional
Describe the process of relief rainfall
Warm moist air blown in from sea
Air forced to rise over mountains
Air cools, condensation occurs and rain falls (on windward side)
Air has lost most of it moisture, air sinks and warms, so there is less rain
A rain shadow is created on the leeward side of a mountain which receives less rain
Describe the process of cyclonic rainfall
Two air masses meet (one warm, one cold)
The warm, moist air is forced to rise over the cold air
The warm air cools, condensation occurs and rain falls
Describe the process of convectional rainfall
Ground is warmed by the sun
Air warmed by the ground rises
Warm air cools, condensation occurs and rain falls
Define precipitation
Water vapour when it is formed into rain, hail, sleet or snow
What is a rain shadow
An area in the sheltered or leeward Sid elf mountains that receives less rain than the windward side
