Geography - Weather Flashcards
weather
- day-to-day conditions of the atmosphere
- able to change quickly (Day 1 - dry II Day 2 - rain)
e.g. sunshine, rain, hail …
climate
- average weather conditions (over a long period of time & large areas)
- usually measured over 30 years
e.g. tropical, polar, continental…
elements of weather
- humidity
- sunshine
- air pressure
- temperature
- wind
- precipitation
- drought
humidity
- how much moisture there is in the air
sunshine
- light and heat that comes from the sun
air pressure
- whether the air is rising/falling
wind
- movement of air
temperature
- how hot or cold somewhere is
precipitation
- anything made out of water that falls from the sky
drought
- unusually dry weather
factors affecting local weather
- physical features
- shelter
- aspect
- buildings
- surface
physical features
- trees provide shade & shelter, creating cool areas
- water makes the area colder (e.g. lakes and seas)
- hill tops are usually cool and windy
shelter
- trees, hedges, walls, buildings & hills provide shelter from the wind
- wind speed may be reduced & direction can change
- places sheltered from wind = warm
aspect
- the direction a place is facing is called aspect
- places facing the sun will be more warmer than those in the shadow
- south facing places get the most sun & therefore is the warmest
buildings
- give off heat that has been stored from the sun during the day
- can reduce the wind speed
surface
- color of the ground affects the temperature of the ground
- dark surfaces (tarmac & soil) will be warmer than light surfaces (grass)
importance of rain
- essential part of water cycle
- understanding reasons it rains, helps us understand the weather reports
- can be channeled and stored in reservoirs (can be used agriculture, growing crops)
- flooding can be avoided if warned
- with very little rain drought can occur
- can be used for hydroelectric electricity
why are the polar regions cold and dry?
the angle of sunlight is small => the sun is always low in the sky => solar energy is less concentrated (weaker)
types of rainfall
=> convectional
=> relief
=> frontal
low pressure system
- blows wind inwards
- clouds in the sky
high pressure systems
- blows wind outwards
- cloudless skies
frontal rainfall
- An area of warm air meets the area of cold air
- The warm air is forced over the cold air
- Where the air meets the warm air is cooled and water vapor condenses
- Cloud form and precipitation occurs
places:
east asia
north america
new Zealand
Europe
relief rainfall
- prevailing winds bring warm, moist air to the western British isles
- air is forced to rise over high areas
- air cools and condenses
- cloud form and it rains
- air descends on the other side of the mountains
- it warms up and therefore become drier
places:
east coast of usa
uk
japan
convectional rainfall
- the sun heats the ground and warm air rises
- as the air rises it cools and water vapor condenses to form clouds
- when the condensation point is reached large cumulonimbus clouds are formed
- heavy rain storms occur. these usually include thunder and lighting due to the electrical charge created by unstable conditions
places:
south east asia
central Africa
extreme weather
- weather event is significantly different from the average or usual weather pattern
- can take place over one day or a period of time
weather warning system
to alert people to potentially dangerous weather
extreme weather examples
- heat waves
- cold waves
- droughts
- hail
- heavy rain
impacts of extreme weather
- injuries when attempting to escape
- deaths
- mental health
precipitation
- any form of water
- liquid or solid
e.g. rain, sleet, snow, hail
prevailing wind
- come from the south west carrying moisture from the Atlantic ocean
