Weather & Climate - Mill Hill School€¦ · Weather & Climate Weather is the day to day...

Weather & Climate

Weather is the day to day atmospheric conditions - hot/cold, wet/dry, windy, cloudy Climate is the average weather over a period of time (several years) – polar, tropical, desert

Factors affecting climate

Distance from sea

H – Himalayas (mountains are cold) Greenland’s ice reflects the sun Southern hemisphere – does not get so cold as there is more ocean warming it Northern hemisphere has more landmass so gets either hotter or colder depending on the session

Our prevailing wind is from the South West – so warm and wet (Tropical Maritime)

Prevailing Winds in the UK

Ocean currents

Warm water from the Caribbean warms Britain – which should be as cold as Canada!

North Atlantic Drift

Relief and Rainfall

Britain temps

Types of rainfall

Relief Frontal Convectional

Warm air rises cools and water vapour condenses to form clouds which leads to rain

Climate graph

This is the climate graph for Britain

This is the climate graph for a hot desert, i.e. the Sahara

This is the climate graph for the Mediterranean

This is the climate graph for Equatorial climate, i.e. in Nigeria

The bar graph is for the average rainfall, and the line graph is for the average temperature

Microclimate Aspect – south facing slopes are warmer

Relief/altitude – higher land is colder and exposed to wind

Surface – darker surfaces absorb heat, light materials reflect light

Buildings – give off heat (central heating/air conditioning) cities create

their own microclimate known as Urban Heat Island

Distance to water – has an insulating effect in summer and radiates heat in winter

Shelter – protect from the wind

Floods

Floods Causes

Heavy rain Continuous rain Steep slope Impermeable soil Snow melt Saturated / waterlogged Soil Drought – causes dry hard ground

Deforestation Urbanisation Changes to drainage - bridges

Physical factors Human factors

Floods - effects Property destroyed Loss of life Transport disrupted Economy damaged Habitats destroyed – plants & animals die Loss of power supply Water polluted - disease Famine – crops destroyed

Flood defence/prevention

Afforestation – plant trees Embankments / levees– higher river banks Straighten channels Widen / deepen channels Secondary channels Build dams

Bangladesh - case study Polluted water supplies Famine Drowning Property destruction Transport & communication links damaged

Climate – average weather over a period of time

Weather – day to day atmospheric conditions

Microclimate – climate in a small area

Relief rainfall – rain cause by moist air rising over mountains

Glossary