How much of the Earth's surface is covered with water?
three-fourths (3/4)
What two areas strongly influence global wind systems?
The land and oceans
What causes some areas of the Earth to be warmer than others?
Uneven heating by the Sun
What happens to warm air?
It expands, becoming lower in density (and lighter) than cold air, and has a lower pressure.
What is wind?
The movement of air from an areas of higher pressure to an area of lower pressure.
Why does the Earth receive different amounts of radiation from the Sun?
Because it is curved.
What area of the Earth receives more radiation than the areas to the north or south?
The equator
What happens to the heated air at the equator?
It is less dense so it is displaced by denser (heavier) colder air. The displacement creates convection currents.
What is a convection current?
The transfer of heat by the flow of material (eg. wind current).
What happens to the cold air at the poles?
It is denser (heavier) and has high-pressure causing it to sink and move along the Earth's surface, creating wind.
Does the rise and fall of dense air explain everything about what causes wind?
No
What is the Coriolis effect?
It causes moving air to turn to the right in the northern hemisphere and to the left in the southern hemisphere.
What causes the Coriolis effect?
The rotation of the Earth
What do wind systems or patterns impact?
The weather, and when and where ships and planes travel most efficiently.
How did Christopher Columbus get from Spain to the Americas?
His ships had only wind power so the sailors used the wind patterns on Earth to move the ships.
What are the names of the three ships that sailed with Christopher Columbus?
The Nina, the Pinta, and the Santa Maria
What are doldrums?
A windless, rainy zone hear the equator.
Why did ships avoid sailing near the equator?
Because the area of warm air caused it to rise creating a low pressure and little wind. As the rising air cools, it causes rain.
What are Trade Winds?
The air descending to Earth's surface near 30 degrees north and south latitude. A steady wind that blows in tropical regions.
Why are Trade Winds called "Trade winds"?
Because early sailors used their dependability to establish trading routes.
What are the prevailing westerlies?
Winds between 30 and 60 degrees latitude that blow in the opposite direction of the trade winds.
What winds are responsible for much of the movement of weather across North America?
The pervailing westerlies
What are the polar easterlies?
Winds found near the poles.
What direction do winds near the north pole blow?
from northeast to southweat
What direction do winds near the south pole blow?
from the southeast to the northwest
What are jest streams?
narrow belts of strong winds
What narrow winds blow near the top of the troposphere?
The jet stream
What is the polar jet stream?
It forms the boundry of cold dry polar air to the north and warmer moist air to the south.
When does the jet stream move faster and why?
It moves faster in the winter because the difference between the cold and warm air is greater.
What impact does the jet stream have on the weather?
It helps move storms across the country
How do airplane pilots use the jet stream?
When flying eastward, they take advantage of the jet stream saving time and fuel. When flying west, pilots avoid the jet stream by flying at different altitudes.
What do global wind systems impact?
major weather patterns for the entire planet.
What do smaller wind systmes impact?
local weather
What is a sea breeze and how is it created?
wind blowing from the sea toward the land. It is created during the day because solar radition warms the land more than the water. Air over the land is heated by conduction. This heated air is less dense and has lower pressure. The cooler, denser air over
What is a land breeze?
Wind blowing from land toward the sea. When land cools much more rapidly than ocean water, the air over the land becomes cooler than the air over the ocean. The cooler, denser air about the land moves over the water and the warm air over the water rises.
What type of wind is movement of air toward water?
Land breeze
What type of wind is movement of air from the ocean toward land?
Sea breeze
Sea and Land breezes are caused by?
The land heats and cools more quickly than the water.
The _____________ is caused by the Earth's rotation.
Coriolis effect
Teh air above the ____________ rises because it has low density and low pressure.
equator
Cold air has more molecules occupying a cubic centimeter of space than warm air; therefore, it has _______ pressure.
higher
When cool, dense air from over the water flows inland it is called a?
sea breeze
Stead winds between the equator and 30 degrees latitude north or south are known as
Trade winds
The flow of air caused by ______________ and the Coriolis effect creates distinct wind patterns on the Earth's surface
differences in heating