Global Air Movement

Hadley CellsFerrel CellsPolar CellsJet Stream

Hadley Cell

1. Warm air rises from the equator out away

from earth.2. It makes its way north and as it cools it

sinks.3. It runs into a Ferrel cell and the warmer air

moves back toward the equator4. Occurs between 0 and 30 degrees north

and south

Ferrel Cells

1. Ferrel cells are located between 30 degrees

and 60 degrees both north and south.

2. Warmer air moves up and away from the

earth and heads north until it bumps into a

polar cell.3. The cold air sinks and moves back to the 30

degree area from where it started

Polar Cells

1. Warm air moves upward away from the earth headed to the poles.

2. It cools down even more and returns to bump into the Ferrel cell air

Equator 0

○

30○ N

30○ S

60○ N

60○ S

90○ S

90○ N

WESTERLIES

TRADE WINDSS

POLAR EASTERLIES

Dead Horse Lattitudes

1. About 30-35 Degrees both North and South of the equator.

2. Seamen were broke having spent their advances. By the time they worked off their Dead horse debt they were in the Horse Latitudes. They had a ceremony for it.

3. Also called the doldrums or calms.4. Dry air coming down from the

Hadley Cell meant very little horizontal movement.

Another Theory

When the Spanish brought horses to the new world, they would sometimes get stuck in the doldrums for weeks.

With little moisture in the dry air, they would have no water to give to the horses, so they would throw the dead overboard.

Air Movement

Since the earth spins around, the air does not move in a straight line toward the poles.

Instead, the movement is diagonal in certain directions. We live in a westerly pattern.

That is why much of Texas weather comes from the west.

The Jet Stream

Formation of Jet Streams

1. High altitudes near the tropopause where the troposphere and stratosphere meet.

2. Form near where Ferrel and Polar cells meet. A lot of fast moving air there where they meet.

3. Meteorologists use its location to help in weather forecasts

The Snake

4. The jet stream slithers across the atmosphere like a snake.5. Jet streams may start, stop, split

into two or more parts, combine into one stream, or flow in various directions including the opposite direction of most of the jet.

6. Their movements pull air from the cells in along with them.

The Slithering Snake-Jet Stream