Weather Flashcards
State the four factors that affects weather?
- latitude
- relief
- aspect
- distance from the sea
How does latitude affect the weather?
Places closer to the equator are usually warmer, and places nearer the poles are colder.
Explain how relief affects weather.
Places located on flat low-lying land are warmer and higher up are colder and wetter.
Explain how aspect affects weather.
Places which are south-facing are warmer and places which are north-facing are colder.
Explain how the distance from the sea can affect the weather.
Places nearer to the sea are mild and wet, and places further from the sea are drier but temperatures are more extreme.
What is an air mass?
A large volume of air which travels from one area to another.
What determines the weather an air mass brings?
The region the air mass has come from and the surface it has moved over.
Name the 5 main UK air masses.
- tropical maritime
- polar maritime
- arctic maritime
- polar continental
- tropical continental
If an air mass passes over land will the weather be dry or wet?
Dry
If an air mass passes over an ocean will the weather by dry or wet?
Wet
What weather will an air mass that has passed over tropics bring?
Warm temperatures.
What weather will an air mass that has passed over the arctic bring?
Cold temperatures
What is the source area and weather characteristics of the Tropical Maritime (mT) air mass?
Source area = Atlantic Ocean
Weather characteristics = warm and wet
What air mass passes over Southern Europe and North Africa and brings warm and dry weather?
Tropical continental (cT)
What is the source area and weather characteristics of the Polar Maritime (mP) air mass?
Source area = North Atlantic
Weather characteristics = cold and wet
What air mass passes over Northern Europe and brings cold and dry weather?
Polar continental (cP)
What is the source area and weather characteristics of the Arctic Maritime (mA) air mass?
Source area = Arctic Ocean
Weather characteristics = very cold but not always wet due to low humidity
What is a synoptic chart?
A more detailed weather map which shows which type of weather system is moving over Britain.
What is the main element that a synoptic chart measures?
Air pressure
What are isobar lines?
Lines that join up areas of equal air pressure. The pattern they make shows areas of low or high pressure.
What is a depression?
An area of low pressure which moves from west to east in the northern hemisphere.
How can low pressure systems be identified from a synoptic chart?
- cold fronts
- warm fronts
- possible occluded fronts
- tightly packed isobars
- isobars showing pressure decreasing towards centre
In a low pressure system what front if the first to pass over?
Warm front
Explain how a warm front is produced.
A warm front occurs when warm air meets cold air and the warm air rises above it.
What weather does a warm front bring?
Steady continuous rain (and increasing winds, cloud cover and a slight rise in temperatures).
What is the second front to pass in a depression?
A cold front.
How does a cold front occur?
When cold air meets warm air. The cold air pushes the warm air upwards.
What weather do cold fronts bring?
Heavy rain showers (and stronger winds and large clouds).
What is formed when the cold front catches up with the warm front in a depression?
An occluded front.
What weather do occluded fronts bring?
Sudden downpours of heavy rain.
What is the warm sector?
The warm sector is found between the warm and cold fronts and conditions tend to settle, skies are dull and cloudy, temperatures rise slightly and there is little rain.
What pressure systems does widely spaced isobars indicate?
High pressure systems (or anticyclones).
What are anticyclones?
Anticyclones are areas of high pressure which bring calm, bright sunny conditions. (However temperature depends on time of year).
