Geography weather and climate

weather

The day to day conditions, e.g. precipitation, cloud cover, wind speed and direction and temperature.

climate

what to expect based on the average weather conditions for that time of year in that place

Basic differences between weather and climate

weather = current conditions, climate = what to expect based on averages

What factors control our temperature and climate?

Latitude, altitude, prevailing wind, ocean currents, distance from the sea

How does latitude influence the weather and climate in the UK?

Places further away from the equator are cooler as the sun passes through more atmosphere and looses more energy before it reaches the earth. The suns rays hit the earth at more of an angle in the northern hemisphere.

How does altitude influence the weather and climate in the UK?

The higher you are the cooler it is. For every 100m you climb the temperature lowers 1 degree. Higher altitudes have thinner air.

How does prevailing wind influence the weather and climate in the UK?

Prevailing wind is the most common wind direction. The movement of air from America brings warm air to the UK

How do ocean currents influence the weather an climate in the UK?

The north Atlantic drift and other ocean currents make it warmer in the west during the winter months.

How does distance from the sea influence the weather and climate in the UK?

The sea keeps coastal areas cooler in summer and warmer in winter. Oceans warm up and cool down slower than land.

How do air masses influence the weather and climate in the UK?

An air mass is a large body of air which has the same temperature and humidity throughout

What controls the temperature and moisture levels in an air mass?

Source regions (flat areas of land)

Tropical air temperature

warm

Polar air temperature

cold

continental moisture content

low moisture content

maritime air moisture content

wet, high moisture content

What is a microclimate

A local set of atmospheric conditions that differ from the surrounding area

What are the 3 types of rainfall

Frontall, relief and convectional

What is frontall rainfall

Occurs when a warm moist air mass collides with a cold air mass. The cold air undercuts the warm air and the warm air rises above the cold air.

What is relief rainfall

Occurs when moist air is forced to rise over hills and mountains. As the air rises it cools and condenses to form clouds. The clouds release the rain above the mountains and hills creating a rain shadow behind them.

What is convectional rainfall

Only occurs where it is hot as the sun heats the earth surface causing large amounts of water to evaporate. The water vapor rises and forms cumulonimbus clouds.

What is precipitation?

Precipitation is any form of water falling from the sky e.g. rain, snow or sleet

What is a temperate maritime climate?

cool to warm summers and cool to mild winters. Small annual scales of temperature. Mild/wet climate influenced by the sea.

What are the 5 micro climate factors?

Physical features, shelter, surface, aspect and buildings

Shelter

Trees, hedges walls buildings and hills all provide shelter from the wind. Wind speed may be reduced and its direction changed. Places sheltered from the wind will be warmer.

Physical features

Trees provide shade and shelter and are usually cooler than surrounding areas. Watery areas such as lakes have cooling effects. Hilltops are usually cool and windy.

Surface

The colour of the ground surface affects warming. Dark surfaces such as tarmac and soil will be warmer than light areas such as grass.

Buildings (temperature)

Buildings give off heat that has been stored from the sun during the day or which leaks from heating systems, temperatures near buildings may be 2-3 degrees higher than other areas.

Buildings (wind)

Buildings break up wind and can reduce wind speeds by up to a third, however, sometimes the wind speed can increase as it rushes round buildings.

Aspect

Places facing the sun will be warmer than ones in shadow. South placing faces get most of the sun and are therefore usually warmest.