Moisture in the atmosphere Flashcards
Types of precipitation:
Dew point and frost , Hail and snow and rain
Precipitation
any form of water particle, liquid or solid, that falls from the
atmosphere and reaches the ground.
convectional rain?
- Occurs when there is intense heating of the Earth’s surface
- Evaporation takes place and moist air rises and cools.
relief or orographic rain?
- Occurs in coastal areas that have hills or mountains.
- Wet, onshore winds from the sea are forced to rise and cool against the mountain.
- When the air cools to its dew point, condensation occurs.
- Relief rain falls on the sea-facing mountain side.
- The other (lee) side is drier.
frontal rain?
- occurs when warm moist air from the frontal system rises over colder
air. - Warm air rises, cools and condenses and frontal rain falls.
Water vapour capacity:
{the maximum amount of water vapour that the air can hold at a
given temperature.
Amount of water vapour in the air depends on the
temperature of the air.
Actual humidity:
The amount of water vapour in the air in grammes per cubic metre
Relative humidity:
It is the amount of water vapour in the air compared to the amount of water vapour the air
can hold at its existing temperature
Relative humidity (RH) = x 100
Dew point:
The temperature at which air is saturated with water vapour
Condensation level:
The altitude at which condensation begins and clouds form
Factors that affect relative humidity:
- Temperature of the atmosphere as this determines the water vapour capacity
What are clouds
are large collections of tiny water droplets or ice crystals.
Forms of water in the atmosphere:
- Solid: Ice in the form of hail and snow
- Liquid: water in the form cloud , fog and rain
- Gas: water vapour
