Large global wind systems are created by the uneven heating of the Earth’s surface. To understand how global winds form and drive the major ocean currents, you need to know that wind is the basically the movement of air from an area of high pressure to an area of low pressure. Because of the Coriolis Effect, the Earth’s rotation causes the air to be deflected. Air is deflected to the right in the northern Hemisphere, to the left in the Southern. The four major wind systems are the Polar Easterlies, Prevailing Westerlies, Easterly Trade winds and the Intertropical Convergence Zone. These are also wind belts. There are three other types of wind belts, also. They are called Trade Winds, Doldrums, and Horse Latitudes. Polar Easterlies (From 90O to 60 O North/South) - Polar Easterlies can be found at the north and south poles and they are cold and dry because of where it is located, which is at high latitudes. This type of wind system forms when cool air, at the poles, and then transfers to the equator. Prevailing Westerlies (From 30O to 60 O North/South) located in the 30-60 degrees latitude in the northern and southern hemispheres. They blow from South West in the Northern hemisphere and South East in the Southern. Sometimes called the "Roaring Forties" because the particularly strong westerly winds in the band between 40 and 50 degrees southern latitude. European ships making their return trip from North and South America would use the prevailing westerlies to put the wind at their back as they sailed back to Europe. Horse Latitudes (From 30O to 35 O North/South) - Horse latitudes are a region where there is weak winds because of high pressure and decreasing dry air. The origin of the name Horse latitudes is that ships that needed wind power couldn't move on the calm water and the sailors threw the horses and cattle over the ship to save on provisions. Easterly Trade winds (From 5O to 30 O North/South) - Easterly Trade winds move from North East in the Northern hemisphere and South East in the Southern. These form as air from the equator rises, it gets warmer and when it cools down, it comes back down to the equator. Trade winds get its name from its capability of blowing trade ships across the ocean, very quickly. By the 18th century the importance of the trade winds to England's merchant fleet for crossing the Atlantic Ocean had led to the name 'trade' or "(foreign) commerce" Intertropical Convergence Zone (From 5O north to 5 O South) - The Intertropical Convergence Zone is also known as Equatorial Convergence Zone or the Intertropical Front. It forms when southest and northeast trade winds converge in a low pressure zone, near the equator. It usually appears as a band of clouds and comes with thunderstorms, which are short but produce extreme amounts of rain. Doldrums (5O north and south of the equator) - Doldrums are just outside of the Intertropical Convergence Zone. The name “Doldrums” originated from some sailor who noticed the stillness in the rising air and called it the "doldrums", which means depression or despondency.

TASK ONE Air (and water) move from areas of high pressure to low pressure. Draw the arrows as you would expect the air to move. Don’t forget about the Coriolis Effect. Arrows should bend to the right in the northern hemisphere and the left in the southern hemisphere

TASK TWO

On the Globe 1, complete the following: Label the location of the Polar Easterlies, Prevailing Westerlies, Easterly Trade winds and the Intertropical Convergence Zone, Doldrums, and Horse Latitudes.

TASK THREE

1. Color North America, South America, Africa, North Atlantic Ocean, South Atlantic Ocean and the Pacific Ocean each different colors. 2. Draw the arrows that represent the global wind patterns, remember draw arrows from high to low and Air is deflected to the right in the northern Hemisphere, to the left in the Southern 3. Use this information in TASK FOUR

TASK FOUR: Choose one of the following. You must use at least FOUR of the new vocabulary words.

1) Complete a two paragraph first person journal entry describing a there and back sailing journey. (For example, Christopher Columbus traveling to the new world and back). 2) Write a technical description on how you would make a journey from North America, Europe, South America and Africa with at least ten steps 3) Create a six panel cartoon of a cross ocean journey 4) Illustrate a sailing map with labels show the best sailing routes for a journey from North America, Europe, South America and Africa