1. 4 3 .
Pressure Systems

2. PRESSURE SYSTEMS Low Pressure Area L
Also known as a cyclone or a depression
Wind flows counterclockwise and inward
Pressure is lowest in the centre
Expect poor weather L

3. PRESSURE SYSTEMS Secondary Low L Smaller disturbance of cyclone nature
Forms within a main depression L

4. PRESSURE SYSTEMS Trough Ridge Col
U-shaped area of low pressure with higher pressure on either side
Trough
similar to a trough but extends outward from a high with lower pressure on either side
Ridge
a neutral area between two highs and two lows
Col

5. PRESSURE SYSTEMS High Pressure Area H also known as anticyclone
wind flows clockwise and outwards
pressure highest in centre
expect fine to fair weather H

6. PRESSURE SYSTEMS

7. NOTE: You must use the buttons in the Confirmation Stage

8. Meteorology Pressure Systems
Let's try a few review questions on Meteorology:
Question #1 - What direction does the wind flow around a low pressure area? A
Anticlockwise and inward B
Clockwise and outward C
Anticlockwise and outward
Clockwise and inward D

9. I’m afraid that answer is incorrect
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10. Flying Scholarship Program
That answer is correct.
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TP312 & TP 14371

11. Meteorology Pressure Systems
Let's try a few review questions on Meteorology:
Question #2 - A U shaped area of low pressure with areas of higher pressure on either side is known as a A
Ridge B
Col C
Trough D
Secondary low

12. I’m afraid that answer is incorrect
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13. Flying Scholarship Program
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TP312 & TP 14371

14. Winds
Winds always flow from an area of high pressure to an area of low pressure. H L

15. Forces Affecting Horizontal Air Movement
Pressure Gradient
The rate of change of pressure over distance measured at right angles to the isobars.
It is steepest when isobars are close.
It determines wind velocity (the closer the isobars the stronger the winds).

16. Forces Affecting Horizontal Air Movement
Coriolis Force
Because the earth rotates beneath the atmosphere, air is deflected to the right in the Northern Hemisphere, until it flows parallel to the isobars.

17. Coriolis Force
Earth rotates counterclockwise
North Pole

18. Forces Affecting Horizontal Air Movement
Surface Friction
Friction between the surface of the earth and the atmosphere will slow the movement of air. This, in turn, increases the angle at which the air crosses the isobars.

19. Forces Affecting Horizontal Air Movement
Buys Ballot’s Law
In the Northern Hemisphere, when you stand with your back to the wind, the low pressure area is to your left.

20. Buys Ballots Law L

21. NOTE: You must use the buttons in the Confirmation Stage

22. Meteorology Pressure Systems
Let's try a few review questions on Meteorology:
Question #3 - Because the earth rotates beneath the atmosphere air is deflected to the right, in the Northern Hemisphere, until it flows parallel to the isobars. This phenomena is known as A
Pressure gradient B
Coriolis force C
Surface friction D
Buys Ballots Law

23. I’m afraid that answer is incorrect
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I’m afraid that answer is incorrect
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24. Flying Scholarship Program
That answer is correct.
Let's move on...
TP312 & TP 14371

25. Meteorology Pressure Systems
Let's try a few review questions on Meteorology:
Question #4 - In the Northern Hemisphere, when you stand with your back to the wind, the center of the low is to your left. This phenomena is known as A
Pressure gradient B
Coriolis force C
Surface friction D
Buys Ballots Law

26. I’m afraid that answer is incorrect
Flying Scholarship Program
I’m afraid that answer is incorrect
Let's try again...

27. Flying Scholarship Program
That answer is correct.
Let's move on...
TP312 & TP 14371

28. Meteorology Pressure Systems Congratulations!!
You have now completed the Pressure Systems lesson of the Meteorology Module. Of course, this lesson is always available to you for future reference if required.
You are now ready to move along to the next Meteorology lesson you have not completed or to any other module you wish. You can advance to the Self Test Module if you feel ready to challenge the final exam.
Good Luck!