Air properties, Coriolis Effect, & Global Wind Patterns

Air properties

• Warm air goes up into the sky.

• Warm air can hold more water than cold air.

• When the warm air rises, it spreads out and gets cooler.

• Cool air can't hold as much water, so it turns into drops and can fall as rain.

• After it cools and spreads out, the air comes back down.

Coriolis Effect

how things, like air and wind, change direction because the Earth is spinning

Coriolis effect continued

• Near the equator (0 to 30 degrees), wind moves from east to west.

• As the air goes up to 30 degrees, it moves back toward the lower pressure at the equator.

• From 30 to 60 degrees, the wind still moves from west to east because the Earth spins faster at 30 degrees than at 60 degrees.

Global Wind Patterns

how air moves around the Earth

Air Movement

Air moves from high pressure at 30 degrees to low pressure at the equator (0 degrees) and 60 degrees

Pressure Differences

At the equator, the air rises and creates low pressure, while at 30 degrees, the air sinks, creating high pressure

Winds near the Equator (0° to 30°)

The winds blow from east to west and are called the Eastern Trade Winds

Winds from 30° to 60°

These winds blow from west to east and are called the Westerlies

Ocean Currents

The wind helps move ocean water: it goes in a circle clockwise in the Northern Hemisphere and counterclockwise in the Southern Hemisphere

Weather Patterns

The Westerlies help create the weather we see in North America