1. What Causes the Wind
Worksheet

2. Definitions
Sea breeze: Cool breeze that blows off the water during the day
Land breeze: Breeze that blows at night from the land to the sea

4. Isobar: Line on a weather map connecting places with the same atmospheric pressure
Coriolis Effect: Apparent curvature of the winds, ocean currents or objects moving long distances along Earth’s surface; caused by Earth’s rotation

6. Jet Stream: Currents or very fast winds that flow in the upper atmosphere; separate hot from warm from cold

8. Anemometer: A device that measures wind speed

10. Pressure gradient: Rate of change in air pressure between two points on a map
Planetary Wind Belts (ESRT 14): Latitude zone of prevailing wind conditions caused by uneven heating of Earth and Earth’s rotation
Prevailing winds: Wind that blows more often from one direction than from any other

11. Key Concepts What causes the wind?
The wind is caused by heat flow by way of convection within the atmosphere
What do winds result from?
Winds result from the uneven heating of Earth’s surface, which causes a difference in air pressure
Cool places usually have relatively high-pressure air pressure and warmer places have relatively lower pressure air pressure

12. ****KEY IDEA**** Winds always blow from areas of high pressure to areas of low pressure

14. Winds always blow fastest where the isobar lines are closest together
The wind direction is influenced by Earth’s rotation
During the day, land heats up more quickly than water
Warm air rising over land causes low pressure, a sea breeze and clouds over the land. This happens during the day.
Warm above slowly cooling water at night creates low pressure, a land breeze and clouds over the water. This happens at night.

15. If the Earth were not spinning, the pattern of wind circulation would be relatively simple.
Without rotation, winds would blow straight from areas of high pressure (North Pole) to areas of low pressure (equator)
In the Northern Hemisphere, winds blowing out of a high pressure area curve clockwise

16. The winds blowing into a low-pressure area turn counterclockwise.
Winds that converge into a low at the surface and rise into the atmosphere must result in winds that  diverge aloft (above).
Low pressure systems are also called cyclones
High pressure systems are also called anti-cyclones

17. Jet streams blow from west to east in mid-latitudes where cold air meets warmer air
Why are jet streams important?  
Jet streams are important because they influence the development and movement of storm systems
Like winds, ocean currents generally move in the same direction

18. *****KEY CONCEPT***** Winds are named by the direction from which they come
Example: A north wind in NYS usually brings cold air because it comes from the Canada/the north.

19. Prevailing Winds
Difference in air pressure and prevailing winds can often mean different weather conditions
Example: In the winter, the northern portions of the US often get cold weather conditions from Canada caused by northerly prevailing winds. In the summer, the same regions usually have more southerly prevailing winds

20. Monsoons: A regular and extreme weather change caused by the shift of wind and pressure belts, which is directly related to the changes in seasons
Example: India- when winds are off the land, India experiences a drought. When winds are off the water, India experiences high amounts of rain

21. Much of the contiguous US is affected by planetary winds that blow from the southwest to the northeast
As a result, weather changes in the US generally move from a southwesterly direction to a northeasterly direction

22. Surface ocean currents are caused by wind blowing over the oceans and transferring energy to the water
The directions of the surface ocean currents are also affected by blocking by landmasses and the rotation of Earth through the Coriolis effect
Since ocean currents result from the transfer of energy from prevailing winds, they can seasonally shit their positions. These changes follow the motions of the vertical rays of the sun