1. Atmospheric Circulation

2. Target #1- I can explain the direction in which air flows across Earth’s surface
Air near Earth’s surface generally flows from the poles toward the equator.
Air moves from high-pressure regions to low-pressure regions
high pressure regions form where cold air sinks toward Earth’s surface
poles
Low-pressure regions form where warm air rises away from Earth’s surface
equator

3. The circulation of the atmosphere and the oceans is affected by the rotation of Earth on its axis
The air flows faster and over a farther distance at the equator
When air moves to the poles, it travels faster than the land beneath it rotates
Causes air to flow in a curved path
Target #2- I can summarize the impact the Coriolis effect has on wind patterns in the atmosphere

4. Coriolis Effect
The tendency of a moving object to follow a curved path rather than a straight path because of the rotation of the Earth
Examples: wind and water
Objects deflect to the right in the Northern Hemisphere and to the left in the Southern Hemisphere
The faster an object travels, the greater the deflection

6. The air that flows from the poles toward the equator does not flow in a single strait line
Each hemisphere contains three looping patterns of flow called convection cells
Each cell correlates to an area on Earth’s surface known as a wind belt
Target #3- I can describe how air moving through convection cells make up Earth’s windbelts

7. Types of wind belts Trade Winds
Names according to the direction from which they flow
Both trade wind belts meet along the equator in an area known as the doldrums
Air moves towards the equator from east to west (easterly)
Westerlies
air moves away from the equator from west to east (westerly)
Polar Easterlies
Strongest in Antarctica
Often stormy where it meets with the Westerlies
Air moves towards the equator from the pole in an easterly direction

9. Target #4- I can describe jet streams
Narrow bands of high-speed winds that blow in the upper troposphere and lower stratosphere
Types
polar jet stream
Subtropical jet stream

11. Target #5- I can describe how fluctuations in the jet stream can cause weather phenomena in the United States
Impacts weather patterns in North America
If the stream undulates further north it results in high temperatures
Ex: In June 2013, McGrath Alaska had a record high of 94 degrees. A few weeks earlier they had a record low of 15 degrees
If the stream undulate further south, it results in much lower temps and usually brings storms
Ex: the snow the northeast has gotten in February is because of the cold air from Canada interacting with the moisture of the Atlantic

12. Target #6- I can compare land and sea breezes
Local Winds
Winds can also exist on a smaller, more local scale
Not a part of the wind belts
Land vs Sea Breezes
As the land heats up during the day, its temperature rises above that of the ocean
Results in hotter air over land
As the hot air rises, the cool ocean air moves inland creating a seabreeze
As the land cools off at night, the air descends creating a sea bound breeze known as a land breeze

13. Target #7- I can state how wind is measured
There are two basic wind measurements direction & speed
Direction is determined by where the wind is coming from
Ex: a north wind is blowing from north to south
Instruments
Direction is most commonly determined using a wind vane
Speed is determined by an anemometer

14. Target #8- I can describe prevailing winds
If a wind blows more often from one direction, it is known as a prevailing wind
In the U.S., the westerlies consistently move weather from west to east across the continent