1. Unit 4: Global Challenge
THE NATURAL ENVIRONMENT
Changeable Weather
Aim: to understand mid-latitude weather systems
Key questions…
What sort of weather does the UK experience?
What are the air masses affecting the UK?
What impact does this have on weather in mid-latitude regions?

2. Britain’s varied climate…
Mild summers, cold winters, dry
Mild summers, mild winters, wet
Warm summers, cold winters, dry
Warm summers, mild winters, quite wet

3. Recap: What factors affect climate?
Read p Global Challenges and p Geography an Integrated Approach
Activities:
What is meant by the terms ‘air mass’ and ‘source regions’?
What is the prevailing wind in Britain & how does this affect our weather & climate?
Draw an annotated sketch map to show the air flows that affect Britain
Using p22-23 draw & colour isoline maps for Britain (rainfall/summer temps/winter temps/ sunshine)
Describe & explain the variations seen in the maps.

4. Air Mass types
Five main air masses affect Europe

5. Air mass classification
• Tropical Maritime (Tm) - mild and moist
• Tropical Continental (Tc) - warm and dry
• Polar Maritime (Pm) - cool and moist
• Polar Continental (Pc) - cold and dry
• Arctic Maritime (Am) - cold and moist