1. The Coriolis Effect and Weather
Science 10 Day 13

2. What is the Coriolis Effect?
The Coriolis Effect describes the turning of
wind and water due to the Earth’s rotation.

3. Coriolis Effect The Coriolis Effect causes air and water to:
turn to the right in the northern hemisphere
turn to the left in the southern hemisphere.

4. What happens at the Equator?

5. Coriolis Effect Why the difference?
If you were in space, looking down at the north pole, the Earth would be rotating counter clockwise BUT
If you were in space, looking down at the south pole, the Earth would be rotating clockwise.
The Coriolis effect has a huge influence over
weather patterns!...

6. Stop & Think!
If the Earth did not rotate, and was much smaller, there would be a large convection current in each hemisphere.

7. Coriolis Effect
There are actually 3 smaller convection currents in each hemisphere. What influence does the Coriolis effect have on these convection currents?

8. Global (Prevailing) Wind Systems
Section 1.2
Global (Prevailing) Wind Systems
3 major wind systems of
prevailing winds are:
1. Trade Winds
2. Prevailing Westerlies
3. Polar Easterlies
They are caused by:
Convection cells
Coriolis Effect!
The air circulation pattern of the trade winds is opposite to that of the prevailing westerlies. 8

10. UNIT 1
Chapter 1: Inquiring about Weather
Section 1.2
Jet Streams
A jet stream is a narrow band of fast-moving wind caused by temperature differences.
Usually a few kilometers high, and a few hundred meters wide.
Why do you think it’s called the JET stream?
The position of the jet stream varies with the seasons. 10

11. Highs and Lows
Air mass a large portion of air that is nearly uniform in temperature and humidity. On weather maps, you will always see several high and low pressure systems symbolized as 'H' and 'L'.

12. High pressure system: form over cold land.
air cools  becomes more dense and settles.
descending air exerts more pressure on the region below.
when the falling air reaches the ground, it moves outward turns to the right due to the Coriolis affect.
High pressure systems turn clockwise in the Northern Hemisphere.
High pressure systems create clear skies; clouds do not form because air is dry.

13. Low pressure system: form over very hot land i.e. deserts.
Hot ground heats air by conduction  hot air rises.
rising air results in a low pressure zone below it.
Surrounding air moves in to replace the rising air. As it does, it turns to the right due to the Coriolis affect.
Low pressure systems turn counter-clockwise in the Northern Hemisphere.
Low pressure systems bring unstable weather, precipitation and storms.

14. Ocean Currents Also Affect Weather
Where do cool ocean currents originate?
Look at the circular movement of currents – in which direction do they move in the hemispheres?
Where do warm ocean currents originate?

16. The Basics
The Earth is a sphere and rotates on an axis (counterclockwise when looking down at the north pole)
The equator rotates faster than areas further north or south to “catch up”.