Unit 2 Flashcards
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.
D
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
A
This is the only atmospheric variable that always decreases with distance above the ground:
Pressure
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
B
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
B
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
C
The sea level pressure distribution across the world is:
Organized into high and low pressure areas
Northeast has an azimuth value of
45 degrees
The pressure at the bottom of the atmosphere is referred to as:
sea level pressure
In the atmosphere, pressure decreases most rapidly in the:
lower part of the atmosphere
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
C
Vertical pressure changes ___ with height.
non-linearly
Pressure decreases with altitude by 50% with every increase in altitude of how much?
5.5 km
Horizontal pressure changes are ___ than vertical pressure changes.
less
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.
D
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
B
The Equation of State (Ideal Gas Law) gives a relationship between:
pressure, density, and temperature
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
B
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
B
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
D
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
B
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
B
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
D
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
C
The Coriolis Effect is zero at:
The Equator
The Coriolis force:
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
C
The Coriolis force:
A. Is constant
B. Affects the direction of motion
C. Affects the speed of motion
D. Is caused by pressure gradient forces
B
A geostrophic wind:
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.
C
According to the equation of state pressure = pRT,
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
A
According to the equation of state pressure = pRT,
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
A
Humid air is actually less dense than dry air because:
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
B
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
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
C
In the upper atmosphere,
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
A
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?
A. Precipitation
B. Infiltration
C. Evaporation
D. All of the above
D
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?
A. Freezing and melting
B. Sublimation and deposition
C. Evaporation and condensation
D. None of the above
B
Saturation:
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
B
The difference in “water vapor” and “liquid water” is:
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
A
Air that contains as much water as it can hold:
A. Is very heavy
B. Cannot be lifted very high
C. Is saturated
D. Has a very low relative humidity
C
Frost forms on your windshield through which process?
A. Melting
B. Deposition
C. Freezing
D. Condensation
B
Absolute humidity is:
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
A
Saturation vapor pressure is dependent upon this variable:
A. Temperature
B. Air composition
C. Air pressure
D. Time of day
A
The number of grams of water vapor in a cubic meter of air is called the:
Absolute humidity
Humidity:
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
D
Of the following, which is not dependent upon temperature?
A. Specific humidity
B. Relative humidity
C. Absolute humidity
D. Saturation vapor pressure
A
When the relative humidity is 100%:
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
C
The dew point:
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
C
What is probably the most effective index of water vapor content?
A. Absolute humidity
B. Relative humidity
C. Dew point
D. Precipitation
C
When warm, moist air mixes with cold air:
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
B
Condensation nuclei:
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
C
Diabatic processes:
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.
A
Adiabatic processes:
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.
B
A parcel of rising air is least likely to do this:
A. Contract
B. Cool
C. Reach the lifting condensation level
D. Reach an area of lower pressure
A
Once a parcel of air rises above the lifting condensation level, the rate of cooling slows because:
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
A
According to the First Law of Thermodynamics, what should happen to a rising air parcel?
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.
B
When saturation occurs below 0 degrees Centigrade:
A) dew forms.
B) frost forms.
C) nothing forms. Moisture becomes inert.
D) the relative humidity becomes undefined
B
Radiation fog:
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.
A
The difference between fog and a cloud is:
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.
D
During winter on poorly insulated windows, frost forms on the
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
B
Perspiration cools the human body by
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
D
Global warming combined with increasing carbon dioxide amounts may lead to further global warming. This is an example of a
A) negative feedback
B) positive feedback
C) neutral feedback
D) adiabatic feedback
B
Increasing global temperatures leads to increasing global emissions of longwave radiation. This is an example of a
A) negative feedback
B) positive feedback
C) neutral feedback
D) adiabatic feedback
A
There are ________ ways to lift air in the atmosphere.
four
This occurs when a mountain range forces air to rise:
A) frontal lifting.
B) convergence.
C) localized convective lifting.
D) orographic lifting.
D
Fronts:
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
B
Orographic uplift is usually associated with rising air:
A) over the great plains.
B) along the Gulf of Mexico coast.
C) over oceans.
D) along the windward side of mountains.
D
All of the following statements about convergent lifting are true, except:
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.
B
In which state would orographic lifting be most important?
A) Louisiana
B) Florida
C) Kansas
D) Colorado
D
This type of air will keep rising after an initial upward push:
A) statically stable air.
B) statically unstable air.
C) statically neutral air.
D) air that is colder and denser than surrounding air.
B
Ultimately, the buoyancy of a rising air parcel is dependent upon its:
A) composition.
B) volume.
C) concentration of water vapor.
D) rate of cooling relative to the surrounding air.
D
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:
A) absolutely stable air.
B) conditionally unstable air.
C) absolutely unstable air.
D) air that cannot reach the lifting condensation level.
C
This the most important mechanism for stopping the rise of unstable air parcels:
A) encountering a layer of stable air.
B) entrainment.
C) friction.
D) reaching the lifting condensation level.
A
Inversions:
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.
A
Hail formation is associated with:
A) cumulonimbus
B) nimbostratus.
C) stratocumulus.
D) cumulus.
A