Zusammenfassung der Ressource
Humidity and Rainfall
- Relative Humidity
- a.k.a RH
- proportion of water vapour in the air
inrelation to the maximum amount of
air can hold at a given temperature
- expressed as percentage
- saturation is 100% RH
- saturation occurs when there is max
amout of water vapour in the air
- Evaporation is not possible when the air is saturated
- Precipitation
- refers to any water falling from the atmosphere to the earth's surface
- 2 types of rain : convectional and relief rain
- 1. Clouds are made up of water droplets
- 2. These water droplets combine to form big water droplets.
- 3. The big water droplets became too heavy and fall as rain.
- Convectional rain
- 1. Intense insolation -> rapid evaporation
- 2. Large quantity of water vapour rises rapidly -> condensation -> clouds
- 3. Cumulonibous clouds -> anvil / mushroom shaped
- 4. Heavy downpour over a short duration within a small area, thunder and lightning are common
- Relief rain
- Occurs when heavy
moist air is forced up
a landform of higher
altitude by winds
- 1. When moist air rises, the
surrounding temperature
falls -> rising RH and
promotion of condensation
- 2. Clouds cannot hold the
heavy water droplets ->
rain on the windward side
- 3. clouds pass over the
mountains, most
moisture released -> dry
air
- 4. Leeward side -> no rain -> rain shadow
- Atmospheric pressure
- Atmospheric (air) pressure is the weight of the air exerted on the earth"s surface
- Dependent on temperature and altitude
- Lower temperature -> air molecules packed closer -> greater weight exerted per unit are -> higher air pressure
- Low land -> low altitude -> more air above -> higher air pressure
- Movement of air from high pressure to low pressure
- Land and Sea breezes
- Climate types
- Tropical/Equatorial climate
- Found within 10 degrees of Equator
- Natural vegetation : Tropical rainforest, mangroove
- High mean annual temperature of 27 degrees
- No distinct wet or dry season -> rain throughout the year
- Relative humidity of >80%
- High annual rainfall of 150 to 300cm
- Convectional rain is common
- Polar climate
- Summer temperature is about
5 to 10 degrees
- Winter temperature stays
below -15 to 20 degrees
- Large annual temperature range
- Precipitation - mainly snow, only rain in short summers
- Polar climate cover 20% of Earth
- Lack warm summers, have long winters
- Days are short, nights are long
- Strong cold winds
- Treeless tundra, very little vegetation
- Cool temperate climate
- Found within 35 to 70 degrees
- Large variation in climatic data
- Low mean annual temperature o 5 to 10 degrees
- Large annual temperature range of 20 to 30 degrees
- Strong maritime effects on coastal areas
- Low moderate annual rainfall of 30 to 200 cm
- Precipitation -> rain and snow