Unit 2 Flashcards by Donny Geisler

Air pressure is:

A. Measured in pascals by American meteorologists

B. Independent of the density of air

C. Independent of the temperature of air.

D. The sum of the partial pressures of its constituent gases.

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Which of the following is a correct approximation of average sea-level atmospheric pressure?

A. 1013.2 millibars

B. 31 inches of mercury

C. 99 kilopascals

D. 20 pounds per square inch

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This is the only atmospheric variable that always decreases with distance above the ground:

Pressure

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Anticyclones:

A. Have air spiraling into them at lower elevations

B. Have clockwise winds in the Northern Hemisphere

C. Do not have winds in the upper atmosphere that follow height contours.

D. Are associated with subgeostrophic winds

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Cyclones:

A. Experience Coriolis effects that deflect air to the right in the Southern Hemisphere

B. Are associated with low-pressure systems

C. Are associated with supergeostrophic winds

D. Are typically regions of fair weather

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In the northern hemisphere, a low pressure system:

A. Has clockwise flow in at the surface and out at the top of the system

B. Has clockwise flow in at the top of the system and out at the surface

C. Has counterclockwise flow in at the surface and out at the top of the system

D. Has counterclockwise flow in at the top of the system and out at the surface

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The sea level pressure distribution across the world is:

Organized into high and low pressure areas

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Northeast has an azimuth value of

45 degrees

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The pressure at the bottom of the atmosphere is referred to as:

sea level pressure

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In the atmosphere, pressure decreases most rapidly in the:

lower part of the atmosphere

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Sea level pressure:

A. is usually less than surface pressure

B. is used in the US, but not in Canada

C. is used to correct for elevation differences at different locations

D. Usually disregards the effect of temperature on air pressure

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Vertical pressure changes ___ with height.

non-linearly

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Pressure decreases with altitude by 50% with every increase in altitude of how much?

5.5 km

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Horizontal pressure changes are ___ than vertical pressure changes.

less

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Which of the following is true?

A. Surface pressure is always greater than sea level pressure

B. Surface pressure is always equal to sea level pressure

C. Sea level pressure is always greater than surface pressure

D. Surface pressure is almost always lower than sea level pressure.

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The Sears Tower in Chicago is 110 stories tall. Atmospheric pressure is greatest at the

A. top of the building

B. bottom of the building

C. 50th floor

D. the pressure is equal on all floors

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The Equation of State (Ideal Gas Law) gives a relationship between:

pressure, density, and temperature

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The equation of state (Ideal Gas Law) is not dependent upon this:

A. The density of the gas

B. The composition of the gas

C. The temperature of the gas

D. The pressure of the gas

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According to the Ideal Gas Law, the pressure will increase if:

A. The air density and temperature decreases

B. The air density increases while the temperature is held constant

C. The air density and the temperature are held constant

D. None of the above

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The horizontal pressure gradient force (pgf):

A. Is solely responsible for air movement

B. Can affect the direction of wind flow

C. Is always directed from high pressure to low pressure

D. All of the above

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The pressure gradient force:

A. Can be measured by knowing the sea level pressure of just one point

B. Creates wind if it is horizontal

C. Will not necessarily result in the movement of air

D. Is unrelated to the speed of air movement

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Horizontal pressure gradients:

A. Are typically quite large

B. Often range over distances of hundreds of kilometers when viewed in large scale

C. Are smallest when measured across a hurricane

D. Can be quite large when compared with the average value of the air pressure

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The horizontal pressure gradient force is proportional to:

A. The speed necessary to achieve hydrostatic equilibrium

B. The change in temperature expressed in Kelvin degrees

C. The change in air density

D. The spacing between isobars

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An examination of a typical 500 mb height map shows that:

A. Pressure surfaces can change dramatically over a short distance

B. There is no usefulness in consulting height maps for other pressures

C. Upper-atmosphere gradients are typically small

D. It takes strong gradients to produce strong winds

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The Coriolis Effect is zero at:

The Equator

The Coriolis force: ## Footnote A. Determines the motion in which water will spiral down a drain B. Causes a deflection to the right in the Southen Hemisphere C. Has a greater effect the longer it acts D. Operates independently of Newton's Second Law

The Coriolis force: ## Footnote A. Is constant B. Affects the direction of motion C. Affects the speed of motion D. Is caused by pressure gradient forces

A geostrophic wind: ## Footnote A. Follows the pressure gradient force B. Curves around to flow toward its original source C. Flows perpendicular to the pressure gradient force D. Is usually not affected by the Coriolis force.

According to the equation of state pressure = pRT, ## Footnote A. An increase in pressure requires an increase in density or temperature or both B. An increase in pressure requires an increase in both density and temperature C. An increase in pressure requires a decrease in density or temperature or both D. An increase in pressure requires a decrease in both density and temperature

According to the equation of state pressure = pRT, ## Footnote A. An increase in density requires an increase in pressure or a decrease in temperature or both B. An increase in density requires an increase in both pressure and temperature C. An increase in density requires a decrease in pressure but not temperature D. An increase in density requires a decrease in both pressure and temperature

Humid air is actually less dense than dry air because: ## Footnote A. Lighter air molecules like O₂ and N₂ are replaced by heavier H₂O molecules B. Heavier air molecules like O₂ and N₂ are replaced by lighter H₂O molecules C. The greenhouse effect is enhanced when the humidity is high D. The greenhouse effect is reduced when the humidity is high

According to the equation of state Pressure = pRT, if pressure remained constant and the temperature increased, what would the density do?

The density would have to decrease

At the equator, the altitude of the 500 mb level is always larger than it is at the north pole because ## Footnote A. The air usually has higher pressure at the equator B. The air is always denser at the equator C. The air is always warmer at the equator

In the upper atmosphere, ## Footnote A. Horizontal pressure gradients are smaller than vertical pressure gradients B. Horizontal pressure gradients are the same as vertical pressure gradients C. Horizontal pressure gradients are larger than vertical pressure gradients D. Pressure is relative constant

The difference between a north-northeasterly wind of 20 degrees and a north-northwesterly wind of 340 degrees is...

40 degrees

The amount of pressure that a given gas contributes to atmospheric pressure is that gas's \_\_\_.

partial pressure

Northern Hemisphere winds rotate clockwise around these: \_\_\_.

anticyclones, or high-pressure systems

An elongated zone of low pressure is known as a \_\_\_.

trough

An elongated zone of high pressure is known as a \_\_\_.

ridge

Why are clouds and precipitation commonly associated with cyclones?

Air converges into a cyclone and this causes upward vertical motion. As air rises, it cools, forming clouds and precipitation

Why is good weather usually associated with anticyclones?

Air diverges from an anticyclone and this causes sinking motion, thereby promoting less cloudiness and dry weather.

The apparent deflection of objects moving in the air that is caused by the rotation of the earth is called the \_\_\_.

Coriolis force (effect)

The residence time of water in the atmosphere is about:

10 days

Which of the following are processes that occur under the Hydrologic Cycle? ## Footnote A. Precipitation B. Infiltration C. Evaporation D. All of the above

As the Earth warms, its surface emits more longwave radiation. What is the most likely effect on global temperature?

Should fall

Which of the following pairs of change-of-state processes bypass the liquid state of water? ## Footnote A. Freezing and melting B. Sublimation and deposition C. Evaporation and condensation D. None of the above

Saturation: ## Footnote A. Is a state of disequilibrium B. Occurs when the condensation rate equals the evaporation rate C. Requires the presence of other gases besides water vapor D. Occurs even when there are still substantial fluctuations in the concentration of water vapor above the surface

The difference in "water vapor" and "liquid water" is: ## Footnote A. A matter of internal energy B. The vertical location of the water C. Water that is located over land versus over a body of water D. None. There is no difference between water vapor and liquid water

Air that contains as much water as it can hold: ## Footnote A. Is very heavy B. Cannot be lifted very high C. Is saturated D. Has a very low relative humidity

Frost forms on your windshield through which process? ## Footnote A. Melting B. Deposition C. Freezing D. Condensation

Absolute humidity is: ## Footnote A. Density of water vapor B. The best measure of water content C. Not affected by changes in volume or pressure D. None of the above

Saturation vapor pressure is dependent upon this variable: ## Footnote A. Temperature B. Air composition C. Air pressure D. Time of day

The number of grams of water vapor in a cubic meter of air is called the:

Absolute humidity

Humidity: ## Footnote A. Refers to the ratio of the number of water vapor molecules to the number of permanent gas molecules in a given sample of air. B. Has only one truly useful measure, at least for meteorologists C. Includes the amount of ice suspended in the air D. Is dependent upon vapor pressure

Of the following, which is not dependent upon temperature? ## Footnote A. Specific humidity B. Relative humidity C. Absolute humidity D. Saturation vapor pressure

When the relative humidity is 100%: ## Footnote A. The specific humidity is greater than the saturation specific humidity B. The saturation specific humidity is greater than the specific humidity C. Water will condense out of the air D. Evaporation ceases

The dew point: ## Footnote A. Has the same relationship to temperature as does relative humidity B. Can only be given in Kelvin degrees C. Is the same as the temperature when the relative humidity is 100% D. Is unrelated to the frost point

What is probably the most effective index of water vapor content? ## Footnote A. Absolute humidity B. Relative humidity C. Dew point D. Precipitation

When warm, moist air mixes with cold air: ## Footnote A. The cold air undergoes adiabatic expansion B. Cloud formation can result C. The temperature of the mixed masses is usually that of the warm mass D. The specific humidity of neither mass is affected

Condensation nuclei: ## Footnote A. Do not include hygroscopic aerosols B. By definition do not dissolve in water C. Are relatively abundant in the atmosphere D. Typically originate as micrometers from space

Diabatic processes: ## Footnote A. Add or remove energy from a system B. Occur when rising air expands and cools without gaining or losing energy. C. Do not always conform to the Second Law of Thermodynamics. D. Are the primary force behind cloud formation.

Adiabatic processes: ## Footnote A. Are relatively uncommon in the atmosphere B. Often involve changes both in temperature and pressure. C. Occur with the addition or loss of energy. D. Are usually not reversible.

A parcel of rising air is least likely to do this: ## Footnote A. Contract B. Cool C. Reach the lifting condensation level D. Reach an area of lower pressure

Once a parcel of air rises above the lifting condensation level, the rate of cooling slows because: ## Footnote A. Latent heat is released when water vapor condenses B. The air surrounding the parcel is cooler C. Water droplets absorb visible light much better than water vapor does D. The parcel of air continues to cool at the dry adiabatic lapse rate

According to the First Law of Thermodynamics, what should happen to a rising air parcel? ## Footnote A) it should get warmer and expand. B) it should cool and expand. C) it should cool and shrink. D) it should get warmer and shrink.

When saturation occurs below 0 degrees Centigrade: ## Footnote A) dew forms. B) frost forms. C) nothing forms. Moisture becomes inert. D) the relative humidity becomes undefined

Radiation fog: ## Footnote A) occurs most often on cloudless nights. B) does not form if there is any wind. C) disappears through "lifting." D) is the type of fog that envelops San Francisco in the summer.

The difference between fog and a cloud is: ## Footnote A) they form via a different process. B) fog never forms in mountains. C) clouds can have ice crystals in them but fog can't. D) nothing. Clouds and fog are a matter of observational perspective.

During winter on poorly insulated windows, frost forms on the ## Footnote A) outside because the warmer temperatures can support higher amounts of water vapor B) inside because the warmer temperatures can support higher amounts of water vapor C) outside because the warmer temperatures can support higher amounts of liquid water drops D) inside because the warmer temperatures can support higher amounts of liquid water drops

Perspiration cools the human body by ## Footnote A) adding sensible heat to the skin as sweat evaporates B) extracting sensible heat from the skin as sweat evaporates C) adding latent heat to the skin as sweat evaporates D) extracting latent heat from the skin as sweat evaporates

Global warming combined with increasing carbon dioxide amounts may lead to further global warming. This is an example of a ## Footnote A) negative feedback B) positive feedback C) neutral feedback D) adiabatic feedback

Increasing global temperatures leads to increasing global emissions of longwave radiation. This is an example of a ## Footnote A) negative feedback B) positive feedback C) neutral feedback D) adiabatic feedback

There are ________ ways to lift air in the atmosphere.

four

This occurs when a mountain range forces air to rise: ## Footnote A) frontal lifting. B) convergence. C) localized convective lifting. D) orographic lifting.

Fronts: ## Footnote A) are rarely involved with cloud formation. B) have substantial temperature gradients at their boundaries. C) are best imagined as vertical walls of air. D) come in three major varieties—cold, warm, and mixed

Orographic uplift is usually associated with rising air: ## Footnote A) over the great plains. B) along the Gulf of Mexico coast. C) over oceans. D) along the windward side of mountains.

All of the following statements about convergent lifting are true, except: ## Footnote A) it requires a difference in pressure between two areas with horizontal separation. B) it typically proceeds diabatically. C) it leads to the rising of air. D) it causes wind.

In which state would orographic lifting be most important? ## Footnote A) Louisiana B) Florida C) Kansas D) Colorado

This type of air will keep rising after an initial upward push: ## Footnote A) statically stable air. B) statically unstable air. C) statically neutral air. D) air that is colder and denser than surrounding air.

Ultimately, the buoyancy of a rising air parcel is dependent upon its: ## Footnote A) composition. B) volume. C) concentration of water vapor. D) rate of cooling relative to the surrounding air.

When the environmental lapse rate exceeds both the dry adiabatic lapse rate and the wet adiabatic lapse rate of a parcel of air, that air parcel contains: ## Footnote A) absolutely stable air. B) conditionally unstable air. C) absolutely unstable air. D) air that cannot reach the lifting condensation level.

This the most important mechanism for stopping the rise of unstable air parcels: ## Footnote A) encountering a layer of stable air. B) entrainment. C) friction. D) reaching the lifting condensation level.

Inversions: ## Footnote A) are characterized by an increase in temperature with altitude. B) increase the positive buoyancy of most air masses that enter them. C) have no significant effect on fog formation. D) are typically unstable.

Hail formation is associated with: ## Footnote A) cumulonimbus B) nimbostratus. C) stratocumulus. D) cumulus.

Stratocumulus clouds are considered: ## Footnote A) high clouds. B) middle clouds. C) low clouds. D) clouds with extensive vertical development.

This is not a form of low cloud: ## Footnote A) stratus. B) nimbostratus. C) nimbocumulus. D) stratocumulus.

Clouds that are high and are always composed entirely of ice crystals are: ## Footnote A) stratus. B) thunderheads. C) alto. D) cirrus. E) nimbus.

High clouds: ## Footnote A) have a typical ceiling around 4500 meters. B) are composed of ice crystals. C) include altostratus clouds. D) have a fairly large water content

Cumuliform clouds: ## Footnote A) are typically much wider than they are tall. B) form in absolutely stable air conditions. C) have very weak vertical velocities within them. D) typically have higher water content than stratiform clouds

Cumulonimbus: ## Footnote A) can span nearly the entire troposphere. B) are prevented by the tropopause from entering the stratosphere. C) are typically composed of ice near the bottoms of the clouds. D) provide smooth flying for commercial airliners.

Which of the following are not in the High Cloud group? ## Footnote A) altostratus B) cirrus C) cirrostratus D) cirrocumulus

The most common mechanism of cloud formation is: ## Footnote A) adding water vapor to the air. B) mixing warm moist air with cold air. C) lowering the air temperature to the dew point by adiabatic cooling of rising air. D) none of the above

Ascending parcels of unstable air seldom extend above the tropopause because ## Footnote A) the troposphere is extremely stable B) the troposphere is extremely unstable C) the stratosphere is extremely stable D) the stratosphere is extremely unstable

Air parcels rising through inversions have ## Footnote A) positive buoyancy B) negative buoyancy C) adiabatic warming D) geostrophic warming

Raindrops fall because: ## Footnote A) they are large compared to atmospheric molecules. B) they are small compared to atmospheric molecules. C) they become large enough that gravity can pull them out of the sky. D) they roll down isentropic surfaces and can't be stopped.

In the collision-coalescence process, the entire cloud is: ## Footnote A) raining. B) snowing. C) below freezing. D) above freezing.

Formation of ice crystals can occur with saturation at temperatures between: ## Footnote A) 0 and 5 degrees C. B) 0 and -5 degrees C. C) -4 and -40 degrees C. D) -40 and -60 degrees C.

Ice crystal growth rates are enhanced by which of the following? ## Footnote A) deposition of water vapor to ice alone B) riming C) aggregation D) all of the above

Cloud droplets fall slowly because they: ## Footnote A) are small. B) carry an electric charge. C) easily get caught in downdrafts. D) have not adhered to condensation nuclei.

The collision-coalescence process: ## Footnote A) is most common at high latitudes. B) is most frequent in cold clouds. C) is dependent upon the different downward velocities of different-sized droplets. D) explains the formation of snow better than it explains the formation of rain.

A collector drop will have the highest collision efficiency with this size drop: ## Footnote A) drops that are much larger. B) drops that are about the same size. C) drops that are somewhat smaller. D) drops that are very much smaller.

Cool clouds: ## Footnote A) contain no water droplets above 0 degrees Celsius. B) contain substantial numbers of ice crystals at all elevations within the clouds. C) have regions with above-freezing temperatures. D) typically form precipitation through the collision-coalescence process.

The Bergeron process: ## Footnote A) is most common in the Tropics. B) is dependent on the growth of ice crystals. C) can take place in cool clouds, but not cold clouds. D) is not dependent on changes in vapor pressure.

Of the following steps in the Bergeron process, which should be second? ## Footnote A) formation of rain drops B) the falling of ice crystals through the cloud C) deposition of water vapor on ice D) net evaporation from supercooled water droplets

The most important principle underlying the Bergeron process is this: ## Footnote A) for a given temperature, the saturation vapor pressure of ice is less than that for supercooled water. B) large drops fall faster than smaller drops. C) aggregation takes place more rapidly than accretion. D) the bottom part of the cloud where the process is taking place must be warmer than 0 degrees Celsius.

Graupel: ## Footnote A) has sharp edges. B) can be as large as hail. C) can provide the nuclei for hail. D) does not contain air bubbles.

Hail: ## Footnote A) requires very strong downdrafts. B) most frequently occurs in sizes greater than two centimeters in diameter. C) can provide the nucleus for graupel formation. D) usually forms in cumuliform clouds

Sleet: ## Footnote A) requires the presence of a warmer above-freezing inversion layer. B) freezes immediately upon touching the surface. C) is usually associated with a cold front. D) is more dangerous than freezing rain.

Freezing rain: ## Footnote A) requires a layer of cold air near the surface. B) is not associated with temperature inversions. C) leaves the bottom of clouds as supercooled droplets. D) is commonly associated with thunderstorms.

During the formation of snow, the atmospheric temperature profile is: ## Footnote A) almost entirely below freezing. B) below freezing in the upper part of the atmosphere. C) below freezing in the lower part of the atmosphere. D) above freezing in the middle part of the atmosphere. E) none of the above

With reference to the Great Lakes, which of the following mechanisms are favorable for precipitation in that area? ## Footnote A) initial mechanism for uplift B) unstable air C) sufficient moisture D) all of the above

What happens to a raindrop if it gets too large? ## Footnote A) evaporates B) stays suspended in the cloud C) breaks up into smaller drops D) turns into a hailstone

Wet growth of a hailstone occurs in an environment ## Footnote A) with weak upper-level winds. B) where the temperature is well below freezing. C) A and B are correct. D) where the temperature is near freezing

Raindrops fall to the ground when: ## Footnote A) they are at least five times the size of a cloud droplet. B) they reach a large enough terminal velocity for both their size and the distance between them and the ground. C) they are able to catch a fast-moving downdraft. D) the coalescence rate exceeds that of the collision rate.

Snow results from all of the following processes, except: ## Footnote A) riming. B) deposition. C) coalescence. D) aggregation.

Precipitation in the eastern two-thirds of North America: ## Footnote A) increases with increasing latitude. B) is dominated by lake-effect snowfalls. C) is influenced by the Gulf of Mexico. D) does not show any longitudinal differences.

The growth of ice crystals in the Bergeron-Findeisen process occurs because: ## Footnote A) the relative humidity is higher in a cold cloud than in a warm cloud. B) of the difference between saturation vapor pressure between ice and water. C) liquid water is attracted to ice because of an electrical charge differential. D) updrafts are extremely strong during the Bergeron-Findeisen process.

Which of the following are associated with orographic uplift? ## Footnote A) Central Valley B) Sierra Nevada C) Willamette Valley D) Puget Sound

Globally, annual precipitation amounts are highest in the: ## Footnote A) mid-latitudes. B) tropical rain forests of South America and Africa. C) east coast of Asia. D) northern Europe.

Lake-effect snow is most common near this lake: ## Footnote A) Lake Tahoe. B) Great Salt Lake. C) Lake Erie. D) Lake Champlain.

In the United States, hail is most common in which of the following regions? ## Footnote A) West Coast B) East Coast C) Great Plains D) Gulf Coast

The effectiveness of cloud seeding is ## Footnote A) widely debated B) generally accepted C) highest in areas that typically receive extremely high rainfall D) highest in remote oceanic areas

The primary ethical issue associated with the practice of cloud seeding is ## Footnote A) the concern that areas downwind of a seeded cloud will be deprived of precipitation B) the concern that resources devoted to cloud seeding activities would be better used in other activities C) the concern that cloud seeding should only be attempted by professional meteorologists D) the concern that cloud seeding introduces toxic chemicals into the environment

Cloud droplets begin forming on \_\_\_\_\_\_\_\_.

Condensation nuclei

What are the main steps in the collision-coalescence process?

As it falls, a collector drop collides with some of the droplets in its path and overtakes some of the smaller droplets in its path, growing larger in the process

These are a mixture of ice and supercooled water in which the Bergeron process can take place: \_\_\_\_\_\_\_\_.

cold clouds

Cyclones and anticyclones are classified as this scale of phenomena: ## Footnote A) synoptic scale. B) mesoscale. C) microscale.

The four scales of atmospheric motion from largest to smallest are: ## Footnote A) planetary, synoptic, meso, and micro. B) planetary, soprano, micro, and meso. C) meso, planetary, micro, bass. D) micro, meso, synoptic, planetary.

An isolated thunderstorm is classified in this scale of atmospheric motion. ## Footnote A) synoptic scale B) mesoscale C) Global scale D) microscale

The single-cell model for general atmospheric circulation: ## Footnote A) works only in the northern hemisphere. B) demonstrates the effect of thermally direct circulations. C) causes wild deviations in the subtropical jet stream. D) is the major cause of the Gulf Stream.

The Ferrel Cell is associated with the: ## Footnote A) tropics. B) mid-latitudes. C) high-latitudes. D) poles.

The ITCZ: ## Footnote A) is an area of high pressure. B) is where trade winds originate. C) forms the boundary between the Ferrel and polar cells. D) receives a lot of rain.

The subtropical high: ## Footnote A) is neither a part of, nor a consequence of, the Hadley cell. B) often causes dry, desert-like conditions. C) has strong pressure gradients. D) has strong winds.

The three-cell model of atmospheric circulation: ## Footnote A) gives a good approximation of what actually happens over the entire Globe. B) is not significantly better than the Hadley model. C) does not address what happens at the poles. D) is better at explaining the ITCZ than at explaining the frequency of easterlies in subpolar latitudes.

The three-cell model for general circulation: ## Footnote A) includes a segment called the Hadley Cell. B) is a better representation of the atmosphere than the single-cell model. C) accounts for the positioning of the Polar and Subtropical jet streams. D) takes in to account the spin of the earth. E) all of the above

The Sahel: ## Footnote A) is located in South America. B) has a rainy season that lasts for nearly nine months out of the year. C) has seen little meteorological change in recent decades. D) is usually dominated by the subtropical high.

Winds in the upper atmosphere are: ## Footnote A) westerly only in the northern hemisphere. B) westerly only in the southern hemisphere. C) westerly in both the northern and southern hemisphere. D) faster in summer than in winter in both the northern and southern hemisphere.

Usually, the pressure gradient force would be strongest at the: ## Footnote A) 950 mb level. B) 900 mb level. C) 800 mb level. D) 700 mb level.

A ________ aloft is associated with ________ air; a ________ aloft is associated with ________ air. ## Footnote A) Ridge/cold; trough/warm B) Ridge/warm; trough/cold C) Low/sinking; high/rising D) none of the above

In the Northern Hemisphere, cold air outbreaks in the winter are commonly related to the movement of the ## Footnote A) subtropical jet stream. B) ITCZ. C) polar front/polar jet stream. D) Pacific High.

Which of the following is NOT a warm current? ## Footnote A) North Equatorial Current B) Gulf Stream C) Canary Current D) North Atlantic Drift

Ocean currents: ## Footnote A) have a much stronger vertical component than horizontal component. B) are driven primarily by differences in ocean temperature over large distances. C) move at a 45 degree angle to the right of surface air flow. D) maintain the same direction at increasing depth

Wind speeds generally increase with height between the surface and the tropopause mostly because of: ## Footnote A) increasing friction. B) decreasing friction. C) the pressure gradient force is stronger at high altitudes. D) the pressure gradient force is stronger at low altitudes.

Monsoons are most dramatic on this continent: ## Footnote A) North America. B) Europe. C) South America. D) Asia.

Monsoon refers to: ## Footnote A) heavy tropical precipitation. B) the climatic pattern in which heavy precipitation alternates with hot, dry conditions on an annual basis. C) heavy summer rains in South Asia. D) none of the above

The two major jet streams that impact weather in the northern hemisphere are the: ## Footnote A) polar jet stream and the low-level jet stream. B) the subtropical jet stream and the low-level jet stream. C) polar jet stream and the subtropical jet stream. D) None of the above. Jet streams are not significant to northern hemisphere weather.

The source of moisture for the Asian monsoon is: ## Footnote A) the snows of the Tibetan Plateau. B) the Indian Ocean. C) evapotranspiration from southeast Asian jungles. D) the Ganges River delta

Sea breezes: ## Footnote A) occur when the temperature at the seashore is higher than that inland. B) require a surface region of high pressure inland. C) result from the fact that water both warms and cools more slowly than land. D) are usually less intense than land breezes.

A valley breeze: ## Footnote A) has more in common with a sea breeze than with a land breeze. B) causes air to flow downward. C) occurs at night. D) is stronger in low ranges of hills than in high mountain ranges.

El Niño: ## Footnote A) Occurs every 10 years or more. B) results from a lower temperature of surface waters in the eastern Pacific. C) results in both reduced air pressure and increased evaporation. D) typically does not affect the northern portion of the United States.

El Niño seems to entail all of the following, except: ## Footnote A) a significant change in the Walker circulation. B) the occurrence of the Southern Oscillation. C) weaker trade winds. D) lower evaporation rates in the eastern Pacific.

A La Niña tends to encourage dry conditions in which of these areas? ## Footnote A) The southern United States B) Pacific Northwest of the U.S. C) Indonesia D) South Asia

Atmospheric features that cover large portions of the earth and are maintained for weeks are considered ## Footnote A) microscale B) mesoscale C) synoptic scale D) global scale

The scale of an atmospheric feature depends on its ## Footnote A) areal coverage only B) time span only C) both areal coverage and time span

The Hadley cell is a ## Footnote A) microscale feature B) synoptic scale feature C) single cell model D) three cell model

Areas close to the ITCZ ## Footnote A) receive abundant precipitation B) receive little precipitation C) receive abundant precipitation, mostly as snow D) frequently experience droughts

The equatorial low is also called the \_\_\_\_\_\_\_\_.

Intertropical Convergence Zone (ITCZ)

Air-mass source regions are least likely to be found here. ## Footnote A) high latitudes B) middle latitudes C) low latitudes D) polar regions

Air masses are generally named according to ## Footnote A) the characteristics of their source regions. B) the season of the year they form in. C) the precipitation they produce. D) all of these

Which of the following are often associated with the passage of a frontal system? ## Footnote A) rapid change in temperature B) shift in wind speed and direction C) change in moisture content D) all of these

Air masses are ## Footnote A) large bodies of air with fairly uniform temperature and moisture characteristics. B) large bodies of air with the same mass. C) large bodies of air with fairly uniform pressure characteristics. D) large bodies of air with fairly uniform wind characteristics.

The boundary between two adjacent air masses is called ## Footnote A) entrainment. B) a front. C) adiabatic. D) an air strip.

The passage of a front often brings ## Footnote A) strange odors. B) clear skies. C) abrupt changes in temperature, humidity and wind. D) abrupt changes in atmospheric composition.

Warming and cooling of the atmosphere varies across the globe due to ## Footnote A) ocean currents. B) the unequal distribution of land and water. C) global warming. D) wind shear.

The temperature, pressure and moisture characteristics of the atmosphere arise mostly from ## Footnote A) the daytime exchange of energy and water vapor between the air and the surface. B) the nighttime exchange of energy and water vapor between the air and the surface. C) the continuous exchange of energy and water vapor between the air and the surface.

Large bodies of air that share similar moisture and temperature characteristics are known as

air masses

Air masses are classified according to the ________ and ________ characteristics of their source regions.

temperature; moisture

Air-mass source regions ## Footnote A) are most common at mid-latitudes. B) are typically on the order of a thousand square kilometers in size. C) typically require many days to form an air mass. D) exist in winter, but not in summer.

Air masses ## Footnote A) all originate from the same place. B) require one to three months to form. C) vary substantially in important characteristics on the horizontal dimension. D) often have large vertical temperature gradients.

An "air mass" is a large body of air that has similar horizontal characteristics of ## Footnote A) moisture and temperature. B) temperature and density. C) density and pollen. D) moisture and winds.

The sources of air masses occur only in low and high latitudes because ## Footnote A) middle-latitude weather is too variable. B) middle-latitude weather is not variable enough. C) there are no oceans in the middle latitudes. D) there is insufficient contrast in surface type (land vs. ocean) in the middle latitudes.

Different air masses have different stability because ## Footnote A) the horizontal temperature variation within an air mass is fairly uniform. B) the horizontal temperature variation within an air mass is not uniform. C) the vertical temperature variation within an air mass is fairly uniform. D) the vertical temperature variation within an air mass is not uniform

Because of differences in ________ some air masses are more likely than others to yield precipitation. ## Footnote A) temperature B) pressure C) stability and moisture D) temperature and pressure

Why aren't air masses classified based on their pressure characteristics? ## Footnote A) because sea-level pressure is fairly uniform across the globe B) because temperature is fairly uniform across the globe C) because moisture is fairly uniform across the globe D) because both temperature and moisture are fairly uniform across the globe

Why are all air masses labeled either "polar," "arctic" or "tropical"? ## Footnote A) because heat exchanges occur only in the low and high latitudes B) because energy exchanges occur only in the high latitudes C) because heat and energy exchanges occur only in the low and high latitudes D) because air masses don't form in the middle latitudes

Why don't continental polar air masses form over Greenland? ## Footnote A) Greenland isn't in the high latitudes. B) Greenland isn't in the low latitudes. C) Greenland is in the middle latitudes. D) Greenland isn't large enough.

Which of the following air masses has short days and low sun angles during winter? ## Footnote A) continental polar B) maritime tropical C) continental tropical D) radiation inversion

List the sources of maritime air masses that affect North America

Maritime polar air forms over the North Pacific as cP air moves out from the interior of Asia. Maritime tropical air masses have an enormous influence on the southeastern United States, especially during the summer. These air masses form over the Atlantic and the Gulf of Mexico and migrate into North America.

List two main characteristics of air mass source regions

* Tend to occur in high and low latitudes where the conditions of temperature and moisture are not highly variable * The source region must be large

Why is mountainous terrain a poor source region for air masses?

Mountainous regions have too much local and large-scale variation of temperature and moisture

Meteorologists have grouped air masses into this number of major categories.

five

Continental polar air-mass source regions are typically ## Footnote A) warm. B) free of snow in the winter. C) cloudy. D) dry.

The coldest air mass is ## Footnote A) maritime polar. B) continental tropical. C) maritime tropical. D) arctic

The ________ air mass forms off the Mexican High Plateau and impacts the southwestern part of the United States. ## Footnote A) Maritime Tropical B) Maritime Polar C) Arctic D) Continental Tropical

Which of the following air masses are dominant over the southeastern U.S., especially in the summer season? ## Footnote A) mP B) cP C) cA D) mT

\_\_\_\_\_\_\_\_ air masses can form over the southwestern United States in summer, and are typically hot and dry.

Continental tropic

\_\_\_\_\_\_\_\_ air masses develop over warm ocean waters in tropical or subtropical regions.

Maritime tropical

An air mass that formed over northern Canada would most likely be designated ## Footnote A) cP. B) mP. C) cT. D) mA.

Continental polar air masses typically form in winter under all of the following conditions, except ## Footnote A) over large, high-latitude land masses. B) over snow-covered areas. C) over areas that absorb large amounts of insolation. D) over very cold areas.

mT air masses ## Footnote A) typically develop over moderately cool waters. B) are stable at their surfaces. C) do not affect the southwestern United States. D) often spawn thunderstorms.

A cP air mass moves southward from Chicago to New Orleans. Which of the following is most likely to occur? ## Footnote A) The air mass would become drier. B) The air mass would moderate. C) The sea level pressure would rise. D) The wind would blow from the south

The ________ is a boundary that forms mainly in the southern Plains and produces severe thunderstorms and tornadoes. ## Footnote A) squall line B) pressure jump line C) gravity wave line D) dry line

Anticyclones generally bring clear skies and calm conditions because ## Footnote A) a strong polar front keeps cold air well to the north. B) adiabatic cooling prevents condensation and latent heat release. C) adiabatic warming prevents condensation and latent heat release. D) adiabatic warming promotes condensation and latent heat release

\_\_\_\_\_\_\_\_ motions within anticyclones generally bring ________ skies. ## Footnote A) Sinking; cloudy B) Sinking; clear C) Rising; cloudy D) Rising; clear

Mid-latitude cyclones ## Footnote A) typically last a month or more. B) do not really have the characteristics and behavior ascribed to them by the theory of cyclogenesis. C) rarely travel more than a few hundred kilometers. D) often bring substantial changes in wind and temperature

The polar front theory of midlatitude cyclones, developed around a century ago, ## Footnote A) has long fell into disfavor among meteorologists. B) has stood the test of time remarkably well. C) was never accepted by the meteorological community.

The polar front theory is remarkable because ## Footnote A) it demonstrated the value of high-powered computers. B) it fully explained the formation, growth, and dissipation of tropical cyclones. C) the developers had to invent new mathematical methods in order to describe it. D) it was developed with far less observational data than we have today.

Midlatitude cyclones ## Footnote A) are commonly experienced by all people living outside the tropics. B) are commonly experienced by all people living within the tropics. C) are rare events confined to the tropics. D) are rare events confined to the middle latitudes.

According to the polar front theory, the stationary front ## Footnote A) will change into cold and warm fronts. B) will change into a cold front. C) will change into a warm front. D) will persist until the cyclone dissipates.

According to the polar front theory, cyclogenesis begins when ## Footnote A) cold air begins to rise above the warmer air. B) an occluded front is formed. C) cold air begins to advance northward and warm air begins to advance southward. D) cold air begins to advance southward and warm air begins to advance northward.

The development of a Mid-latitude Cyclone is called ## Footnote A) Frontolysis. B) Frontogenesis. C) Cyclogenesis. D) Mid-latitude bombs

Mid-latitude cyclones in the Northern Hemisphere typically travel primarily in this direction. ## Footnote A) east B) west C) north D) south

For a mature mid-latitude cyclone, precipitation is least likely at this point. ## Footnote A) near the center of the low-pressure center B) just outside the low-pressure center C) the eastern edge of the cyclone D) near the cold front just below the low-pressure center

Given the implications of the hydrostatic equation, we would expect that ## Footnote A) pressure be independent of altitude. B) cold, dense air would have a greater vertical pressure gradient than would warm, light air. C) differences in temperature on either side of a cold front should not have any significant effect on upper-level pressure. D) differences in temperature on either side of a warm front should not have any significant effect on upper-level pressure.

Persistent drought is often associated with ## Footnote A) a series of strong cyclones. B) persistent zonal patterns in upper-level air flows. C) the occurrence of moving meridional patterns in upper-level winds. D) the coast of British Columbia.

Middle latitude cyclones ## Footnote A) are essentially two dimensional with little vertical structure. B) are essentially two dimensional with little latitudinal structure. C) are essentially two dimensional with little meridional structure. D) are three-dimensional entities.

Anticyclones ## Footnote A) are relatively unaffected by upper-level conditions. B) are only occasionally affected by upper-level conditions. C) are strongly affected by upper-level conditions.

Anticyclones are areas of ## Footnote A) high pressure. B) low pressure. C) developing midlatitude cyclones. D) mature midlatitude cyclones.

Anticyclones have ## Footnote A) clockwise rotation in the northern hemisphere. B) clockwise rotation in the southern hemisphere. C) widespread areas of rising air in the northern hemisphere. D) widespread areas of rising air in the southern hemisphere.

As opposed to cyclones, ________ are often associated with good weather.

anticyclones

Anticyclones ## Footnote A) often bring calm weather. B) are not affected by upper-level conditions to the same degree as cyclones are. C) rarely remain in one place for more than a few hours. D) only appear in the Southern Hemisphere.

Which of the following is true of anticyclones? ## Footnote A) Their widespread sinking motions causes the air to cool. B) Their widespread rising motions causes the air to cool. C) Their widespread sinking motions causes the air to warm. D) Their widespread rising motions causes the air to warm.