WINDS!!!!!!!
By: Alex D
What is wind?
What causes wind?
- when air is heated it expands and becomes less dense
- as it becomes less dense it it's air pressure decreases
- cool less dense air with a high pressure flows under warm air
Local wind
Local winds are winds that blow over a short distance.
How are they created?
They are created by the unequal heating of earths atmosphere creates local winds. Two examples of local wind are sea breezes and land breezes.
sea breezes:
Sea breezes blow during the day.
- Here the land is warmer than the water meaning the air over the land is warmer than the air over water
- the air is lighter over the land than the air over the water so this air rises
- Then the air over the water moves to take its place
- this creates a convection current
Land breezes blow during the evening they are the opposite of sea breezes.
- Here the land is warmer over the sea meaning it is now cooler over the land.
- because of this the air is warmer and lighter over the water
- the air is cooler over the land so when the warm air over the sea rises the air over the land moves in to take it's place.
- This also creates a convection current.
global winds
A global wind is a wind that blows over a long distance usually with the same speed and direction.
How are they created?
They are also created by the unequal heating of earths atmosphere. At the equator warm air rises and cold air sinks at the poles. The differences in air pressure causes winds to blow from the area of higher pressure (poles) to an area of low pressure (equator). The warm air at the poles is then pushed back toward the poles where is cools and sinks. This created a giant current or a convection current.
Doldrums:
These winds are at the equator 0* and are very weak.
Trade winds:
These winds lie between 0* and 30* latitude and are very strong. Sailors use these winds to trade cargo to other countries hence the name trade winds.
prevailing westerlies:
these winds lie between 30* and 60* north and south latitudes and blow from the west.
polar easterlies:
These winds blow from the North and South poles.