Studied by 6 peopleAir pressure
Pressure exerted by the weight of air above.
Because it is exerted in all directions
Why doesn't air pressure crush things?
Mercury barometer, aneroid barometer
What instruments are used to measure air pressure?
Mercury barometer
Created by Torricelli, student of Galileo. Used by filling a glass tube closed at one end with mercury and when mercury flows out of the tube you can see atmospheric pressure.
Aneroid barometer
Uses a metal chamber with air removed it changes shape and compresses as air pressure increases, more portable and smaller, non-toxic.
1013.2 millibars
What is standard sea level pressure in millibars?
Torricelli, Galileo's student
Who invented the mercury barometer?
Solar radiation
What is the ultimate energy source for winds?
Generate wind
What do pressure differences do?
Pressure differences, Coriolis effect, friction
What factors influence winds?
Widely spaces isobars indicate a weak pressure gradient and light winds, whereas closely spaces isobars are opposite
What is the relationship between closely and widely spaced isobars?
Wind
The horizontal movement of air from an area of high pressure to an area of lower pressure
Jet streams
Fast moving rivers of air above the friction layer
wind blows to the right
How does the Coriolis effect influence wind in the Northern Hemisphere?
Wind deflects to the left
How does the Coriolis effect influence wind in the Southern Hemisphere?
It is strongest at the poles and weakest at the equator
Where is the Coriolis effect the strongest and the weakest?
In both hemispheres differences in air pressure cause a net flow of air inward around a cyclone
How do low pressure systems appear in both hemispheres?
In both hemispheres differences in air pressure cause a net flow of air outward around an anticyclone
How do high pressure systems appear in both hemispheres?
Cyclones
Centers of low pressure, the pressure decreases from the outer isobars toward the center.
Anticyclones
centers of high pressure, the pressure increases from the outside towards the center
Warm air rises
What happens to warm air in a cyclone?
Warm air sinks
What happens to warm air in an anticyclone?
Rainy weather
What kind of weather are cyclones associated with?
fair weather
What kind of weather are anticyclone associated with?
Air spirals in toward the center in a counter-clockwise pattern
movement of a cyclone in the Northern Hemisphere
Air spirals in towards the center in a clockwise pattern
Movement of a cyclone in the Southern Hemisphere
Air spirals outwards in a clockwise pattern
Movement in an anticyclone (Northern Hemisphere)
Air spirals outwards in a counterclockwise pattern
Movement for an anticyclone (Southern Hemisphere)
Monsoon
Seasonal changes in wind direction, during warm months areas like India experience a flow of warm water laden air from the ocean which produces a rainy _________ summer.
Trade winds
two belts of winds that blow almost constantly from easterly directions and are located on the north and south sides of the subtropical highs.
Westerlies
dominant west-to-east motion of the atmosphere that characterizes the regions on the poleward side of the subtropical highs.
Polar easterlies
winds that blow from the polar high toward the subpolar low. These winds are not constant like the trade winds.
Equatorial low
a belt of low pressure lying near the equator and between the subtropical highs
subtropical high
A belt of high pressure located at approximately 30o N and 30o S, which pushes heavy subsiding air outward toward both north and south.
Subpolar low
belt of low air pressure at about 60 degrees north and 60 degrees south latitude
Local winds
Small winds produced by a locally generated pressure gradient, caused by topographic effects or by variations in surface composition, land and water, in the immediate area.
Global winds
winds that blow steadily from specific directions over long distances
Sea breezes
During daylight hours, the air above land heats and rises, creating a local zone of lower air pressure. Cooler, denser air over the water moves onto the land.
Land breezes
At night the land cools more rapidly than the sea generating an offshore flow.
Anemometer
What instrument is used to measure wind speed?
After the direction from which they come
How are winds named?
El Niño
At irregular intervals of 3–7 years, these warm countercurrents become unusually strong and replace normally cold offshore waters with warm equatorial waters. Episodes of ocean warming that affect the eastern tropical Pacific.
La Nina
When surface temperatures in the eastern Pacific are colder than average.
Things like fishing and farming in a negative way especially to countries in the Southern Hemisphere
What does El Niño effect?
Strong winds
what do close isobars indicate?
light winds
What do widely spaced isobars indicate?
Note 
Flashcard (31)