The Coriolis Effect and Wind

The Coriolis Effect and Wind Pages 30-31

Global Wind Systems - Table 1.3 – p. 31 Result from the combination of convection currents and the Coriolis Effect Wind System Location Wind Direction (East or West)? Trade Winds - - Prevailing - Westerlies - Polar - Easterlies -

Look at Figure 1.19 and answer the following questions: Which wind system affects Nova Scotia and controls our weather conditions?

What evidence can you see that the global wind systems are the result of both convection currents and the Coriolis Effect?

Spherical Earth and Wind Systems If the Earth did not rotate, winds would move from North to South – from the Equator to the Poles because hot air rises and pushes cold air down (convection currents). Draw Figure 1.16 on page 30.

However, Earth’s actual size means that air sinks long before it reaches the poles. See Figure 1.17 and draw below.

Wind is affected by Earth’s rotation: The Coriolis Effect (see page 30 for a definition): ______• In the Northern Hemisphere, the Coriolis Effect blows the winds from West to East (prevailing Westerlies). That’s the reason why most of our weather systems come from the West of Canada.

Jet Stream – p. 32 • A narrow band of fast-moving wind • Between the troposphere and the stratosphere • Aided by the Coriolis Effect • Winds up to 300 kph

 The polar jet stream, which mostly affects the Canadian climate, forms when the Prevailing westerlies and polar Easterlies meet.  In general, the weather is colder north of the jet stream and warmer South of the Jet stream.

What happens to the jet stream when the seasons change? – During the winter, the jet stream moves south. – During the summer, the jet stream moves up to the North.

Storms form along jet streams and generate large-scale weather systems. These systems transport cold surface air toward the tropics and warm surface air toward the poles.

Label the diagram below to indicate which polar jet stream represents winter in Canada and which one represents summer in Canada.