Wind Patterns

By: Elizabeth H.

BLUE
Last updated: March. 17th 2008

What is Air Pressure..?

"Air Pressure is the measurement of the weight of air". There is both High Pressure and Low Pressure. High pressure is when air molecules are packed closer together and closer to the surface of the earth. High air pressure is around the Polar regions, which makes the climate cold, but mostly DRY. Low Pressure is when air molecules are further apart and spread out. There is low air pressure mainly in the tropics, there, it is hot and rainy.

The reason that wind goes in specific directions on the earths surface is because, the sun heats up the equators surface, and the air on the equator rises, and then goes to the polar regions and sinks. So it is a pattern. In different parts of the world, such as the polar regions where the sun isn't heating up the surface and it is cooler, the air over the land cools and sinks, then moves to the equator and heats up and rises.

Applying Map Skills. (Pg. 55, 2 questions)

1. In which general direction does the wind blow over North America? : From the Westerlies
2. What winds did European sailors use to get to South America and the islands north of it? : To the Northeasterly trade winds

Columbus' Return

This is a picture of columbus' voyage and return from the Canary Islands across the Caribbean sea. As u can see he went in some different directions on his expedition. The reason is because of wind patterns. columbus traveled with the wind, so he could get to his destination as soon as possible. When you look at the global picture of what direction the wind goes it might be easier to see why Columbus did what he did.