Post on 16-Jan-2016
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