1. What are depressions?
8 December 2014
How does low pressure affect the
UK? Depressions.
2. How is this important to
geography?
What are depressions?
3. 8 December 2014
How does low pressure affect the
UK? Depressions.
What are depressions?
Quiz:
Spot the airmass. 5 Questions.
Which Airmass is most likely to be affecting
the UK?
9. Surface pressure chart
Cold Front – colder, polar air behind
Warm Front – Warmer, tropical air behind
What are depressions?
10. What happens when air masses
What are depressions?
meet?
• Key point: Air masses do not mix
• The point a which two or more air masses
meet are called FRONTS
• Air rises, cools, condenses into cloud
21. Low Pressure
Warm Front
Cold Front
Warm Sector
Draw the direction of
air flow
Where
Is Pat?
What are depressions?
22. What are depressions?
Why are there showers
here?
Frontal
Convection
or
Relief rainfall.
Why are there clouds here?
Why is it clearer here?
23. Warm Front Cirrus Clouds Nimbostratus Clouds Intermittent Showers
What are depressions?
Warm Sector
Cold Front
Continuous Rain Showers after the Cold
Front
Rain, Thunder and
Lightening
Cumulonimbus
clouds
1
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