the air pressure pushing down on an object exactly balances________
the air pressure pushing up on the object
How does a barometer measure air pressure?
when air pressure increases, the mercury in the tube rises. When air pressure decreases, so does the height of the mercury column
What three factors combine to control wind?
pressure differences, the Coriolis effect, and friction.
What is the Coriolis Effect
the Coriolis effect describes how Earth's rotation affects moving objects.
What happens in the northern hemisphere in the Coriolis Effect?
all free-moving objects or fluids are deflected to the right of their path of motion
and the southern hemisphere?
all free-moving objects or fluids are deflected to the left of their path of motion.
When the pressure gradient and the Coriolis effect are applied to pressure centers in the Northern Hemisphere_______
winds blow counterclockwise around a cyclone and clockwise around an anticyclone.
What happens in the southern hemisphere?
winds blow counterclockwise around an anticyclone and clockwise around a cyclone
In either hemisphere, friction causes a netflow of air inward around a(n)_____ and a net flow of air outward around a(n)______
1. cyclone 2. anticyclone
What is rising air associated with?
cloud formation and precipitation (rain, snow, sleet, hail, etc)
What is the Non-Rotating earth model?
On a hypothetical non-rotating planet with a smooth surface of either all land or all water, two large thermally produced cells would form.
What are two important things to remember about the non-rotating earth model?
1. It is HYPOTHETICAL!!! 2. the earth would need to be made of ALL land or ALL water.
What is the problem with the non-rotating earth model
some areas would be freezing because of no sunlight and other areas would receive too much sunlight.
What is a polar front?
a stormy frontal zone separating cold air masses of polar origin from warm air masses of tropical origin.
What are local winds?
winds that are caused either by topographic effects (mountains, valleys, etc.) or by variations in surface composition (land and water) in the local area
What are land and sea breezes like in the day?
in coastal areas during the warm summer month, in the day the air moves from high pressure to low pressure. The high pressure is the water and the low pressure is the land. So in the day, wind moves from sea to land.
What are land and sea breezes like in the night?
the land cools faster than the water at night so the air moves to the warm water making the wind blow from land to sea at night.
What are valley and mountain breezes?
the air on the slopes of the mountain is heated more intensely than the air at the same elevation but at the valley floor. The air on the slopes is less dense so it glides up the slope and generates a valley breeze. The pattern may reverse after sunset.
What is an anemometer?
an instrument that resembles a cup and is commonly used to measure wind speed.
What happens at irregular intervals of three to seven years?
the warm countercurrents become unusually strong and replace normally cold offshore waters with warm equatorial waters.
What can a major El Niño cause?
Extreme weather in many parts of the world and the loss of many fish.