The Coriolis Effect and Weather

Science 10 Day 13

http://www.youtube.com/watch?v=WXuGYSM2D8k

What is the Coriolis Effect?

The Coriolis Effect describes the turning of

wind and water due to the Earth’s rotation.

Coriolis Effect

The Coriolis Effect causesair and water to:

– turn to the right in the northern hemisphere

– turn to the left in the southern hemisphere.

What happens at the Equator?

http://youtu.be/-hbE3rTZLbQ

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!...

Stop & Think!

•If the Earth did not rotate, and was much smaller, there would be a large convection current in each hemisphere.

Coriolis Effect

There are actually 3 smaller

convection currents in each

hemisphere.

What influence does the

Coriolis effect have on these

convection currents?

https://www.youtube.com/watch?v=Ye45DGkqUkE

Global (Prevailing) Wind SystemsSection 1.2

3 major wind systems of

prevailing winds are:

1. Trade Winds

2. Prevailing Westerlies

3. Polar Easterlies

They are caused by:

1. Convection cells

2. Coriolis Effect!

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?

UNIT 1

Chapter 1: Inquiring about Weather Section 1.2

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'.

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.

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.

Ocean Currents Also Affect Weather

Where do cool ocean currents originate?

Where do warm ocean currents originate?

Look at the circular movement of currents – in which direction do they move in the hemispheres?

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”.

http://techtv.mit.edu/videos/3714-the-coriolis-effect