Atmospheric Pressure Study Guide

gravity

Air molecules are pulled to Earth by what?

force

A different name for air pressure would be what?

millibars (mb)

How is air pressure measured in the U.S.?

pascal (Pa) and kilopascal(kPa)

What are two other measures of air pressure?

increase the density of air by increasing the amount of air or decreasing the volume of the box, or increase the temperature of the air

How can air pressure be increased?

each gas exerts its own specific pressure

What is partial pressure?

total pressure is equal to the sum of the partial pressure

What is Dalton's law?

True

True or False: Pressure always decreases as elevation increases?

False

True or False: Air pressure is only pulled down and does not function in any other direction?

14.7

What is the air pressure per square inch at sea level?

the horizontal movement of air, done the equalize pressure

Define advection?

allows to compare the air pressure at different locations of elevation, compares all the locations as if they were at sea level

Why is SLP used?

True

True or False: Air pressure does not change at a steady rate?

25 mb

What is the average mb air pressure difference across the United States?

True

True or False: Temperature and pressure are related?

air density increases while temperature remains constant and pressure will increase, or at a constant density, increased temperature will increase pressure

What are the two ways to increase air pressure?

Evangelista Torricelli

Who invented the mercury barometer?

29.92in

In inches, what is the average barometric pressure?

influence of the elevation, temperature - as mercury warms its density changes, differences in acceleration of gravity at higher latitudes

What are the three corrections needed for a barometer?

aneroid barometer

Which barometer tool uses no liquid?

isobars

What is the name for the lines that denote air pressure?

False

True or False: A tight gradient of isobars means calm conditions?

impetus for the movement of air (wind) - if air over one region exerts a greater pressure than another region, the higher pressure moves to areas of low pressure (sets air in motion)

Define the pressure gradient force?

600

The average vertical pressure gradient can be how many times that of horizontal gradients?

air moves from areas of high to low pressure and the greatest pressure differences are horizontal not vertical

Why doesn't wind blow upwards?

because vertical pressure gradient force and the force of gravity are normally of equal value, therefore, they operate in different directions. Hydrostatic Equilibrium

Why isn't all the air pulled down to the surface by gravity?

100 mph

Updrafts can exceed how many miles per hour?

powerful thunderstorms

Updrafts exceeding 100 mph are usually associated with what?

because temperatures are warmer at the surface causing warm air to rise, while the air coming from the poles is denser and sinks, which creates a pressure gradient force causing rising warmer air

Why does air slope upwards when going from the poles to the equator?

looks at the amount of moisture in the atmosphere and helps determine weather directions

Why is the 500 mb level useful in meteorology?

as air moves from high to low pressure the magnitude of the pressure gradient determines the strength of the wind. MAIN POINT - rotation of the Earth causes the apparent deflection (turning) of the wind

How does the Coriolis Force affect wind direction? How?

air in contact with the surface experiences frictional drag, frictional drag decreases wind speed

How does friction affect wind direction?

friction that effects winds within the lowest mile of the atmosphere

Explain the boundary layer?

True

True or False: The free atmosphere has little to no friction?

jet stream

What is an example of geostrophic wind?

high pressure

Supergeostrophic flow is associated with what pressure?

low pressure

Subgeostropic flow is associated with what pressure?

slower

Near the surface, wind is faster or slower because of friction?

enclosed area of high pressure, spirals clockwise

Define an anticyclone?

closed area of low-pressure systems, air at the surface spirals counterclockwise

Define a cyclone?

from areas of high pressure to areas of low pressure

How does air move?

areas of high and low pressure, where ridges are high pressure and move clockwise, while troughs are low pressure and move counterclockwise

What are ridges and troughs?

coming from

Wind direction is named for the direction that it is?

tool that measures both wind speed and direction

What is an aerovane?

differential heating of the land surface and of nearby water causes the generation of NCMC's (local winds)

Describe the formation of a land-sea breeze?

non-classical mesoscale

What does NCMC mean?

Florida

What state frequently has land sea breezes?

big

Is macro scale big or little?

In the cooler months of the year the water is warmer causing the air to blow out to sea. In the summer this reverses and brings the winds over the land from the oceans causing storms.

Explain the formation of the monsoon in SE Asia?

In the late summer months moisture from the Gulf of Mexico is brought into Arizona and New Mexico. The moisture, combined with the heat can generate storms.

How does the monsoon on the SW U.S./Mexico form?

soil moisture differences - created by land-surface boundaries can generate local wind patterns, differences between vegetation types, temperature and moisture differences can create winds, and also increase the chance of cloud development and increased chances for precipitation and severe weather development, including tornadoes

What are other examples of NCMC's? What impacts can they have?

any wind blowing down an incline; opposite to anabatic wind. warm wind called foehn; and cold wind called bora, or a gravity wind (mountain wind) - cold air sinks and is more dense

Define and describe Katabatic wind?

a local wind that forms in mountainous areas that go by various names. can be 40-60 mph with gusts as high as 100 mph warm winds on leeward side of mountain ranges. also called "snow eater" foehn

Define and describe a Chinook wind?

cold air rushes down to the surface, it spreads out and acts as mesoscale cold fronts, created by thunderstorm downdrafts

What are outflow boundaries and what impact can they have?