Deck 5: Atmospheric Moisture

Question 1

Which of the following is water loss to atmosphere by plants and vegetation through a process similar to evaporation?

A)sublimation
B)transpiration
C)interception
D)infiltration

Answer 1

B

Question 2

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.

Answer 2

D

Question 3

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 verses over a body of water.
D)None. There is no difference between water vapor and liquid water.

Answer 3

A

Question 4

Groundwater eventually returns to the atmosphere through which of the following?

A)seepage into rivers
B)human use in agriculture and industry
C)transpiration through plants
D)all of the above

Question 5

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

A)should rise
B)should fall
C)should stay the same

Question 6

Specific humidity:

A)typically has values of 10 percent or greater.
B)is a ratio of one mass to another mass.
C)has little use for scientific studies.
D)is temperature dependent.

Question 7

The residence time of water in the atmosphere is about:

A)12 hours.
B)1 day.
C)10 days.
D)100 days.

Question 8

Which of the following are processes that occur under the Hydrologic Cycle?

A)precipitation
B)infiltration
C)evaporation
D)all of the above

Question 9

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

Question 10

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.

Question 11

Saturation vapor pressure is dependent upon this variable:

A)temperature.
B)air composition.
C)air pressure.
D)time of day.

Question 12

Liquid water at the ground does not always flow along the land surface,but instead penetrates into the ground in the process called:

A)infiltration.
B)interception.
C)transpiration.
D)none of the above

Question 13

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

A)vapor pressure.
B)specific humidity.
C)relative humidity.
D)absolute humidity.

Question 14

Water is unique because:

A)it can be forced through pipes at considerable pressure.
B)its coefficient of expansion as it freezes is linear.
C)it exists in all three states naturally at the same time.
D)it vaporizes at a very low temperature.

Question 15

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.

Question 16

Groundwater results mainly from which process in the hydrologic cycle?

A)transpiration.
B)interception.
C)infiltration.
D)runoff.

Question 17

The effect of humidity and high temperature on human comfort is given by the

A)heating degree-days.
B)cooling degree-days.
C)heat index.
D)moisture index.

Question 18

Frost forms on your windshield through which process?

A)melting
B)deposition
C)freezing
D)condensation

Question 19

The process whereby molecules break free of the liquid volume in which they reside is known as:

A)the solute effect.
B)the curvature effect.
C)evaporation.
D)freezing.

Question 20

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

Question 21

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 percent.
D)is unrelated to the frost point.

Question 22

The relative humidity can increase or decrease even though the water vapor content doesn't change because:

A)relative humidity is tied to the amount of dry air present in the sample considered.
B)water vapor is a locally conservative property of the atmosphere.
C)relative humidity is directly dependent on cloud cover.
D)relative humidity is temperature dependent.

Question 23

A sling psychrometer uses:

A)synthetic fibers.
B)differing electrical resistance.
C)dry- and wet-bulb temperature readings.
D)none of the above

Question 24

The mixing ratio has the most in common with this measure of water vapor:

A)relative humidity.
B)absolute humidity.
C)specific humidity.
D)saturation vapor pressure.

Question 25

Specific humidity:

A)is the most common way to present humidity data in television weather forecasts.
B)is not useful for discussing air that is saturated with water.
C)is a useful measure for comparing water vapor at two different locations.
D)changes as a given mass of air expands.

Question 26

Vapor pressure is:

A)the part of atmospheric pressure due to water vapor.
B)typically measured in millipascals in the United States.
C)a common part of weather reports.
D)independent of temperature.

Question 27

What is probably the most effective index of water vapor content?

A)absolute humidity
B)relative humidity
C)dew point
D)precipitation

Question 28

The dew point:

A)is high when there is little water vapor in the air.
B)can be used with air temperature to indicate the value of relative humidity.
C)can be higher than the current air temperature.
D)is not a very effective indicator of water vapor content.

Question 29

When the relative humidity is 100 percent:

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.

Question 30

The existence of water vapor can:

A)increase atmospheric pressure.
B)decrease atmospheric pressure.
C)cause winds to be stronger.
D)increase the density of a sample of air.

Question 31

As the temperature increases,generally,the relative humidity:

A)is erratic.
B)decreases.
C)increases.
D)is unaffected.

Question 32

The vapor pressure of a volume of air depends on:

A)the temperature of the water vapor molecules.
B)the density of water vapor molecules.
C)A and B.
D)none of the above

Question 33

Humidity:

A)is measured only one way.
B)is unrelated to the vapor pressure of water.
C)is a measure of only the water vapor in the air.
D)applies to water, whether solid, liquid, or vapor.

Question 34

Of the following,which is not dependent upon temperature?

A)specific humidity
B)relative humidity
C)absolute humidity
D)saturation vapor pressure

Question 35

The dew point:

A)is constant for a particular sample of air.
B)determines the next morning minimum temperature, provided no air mass change has occurred.
C)is the temperature air must be cooled to in order for condensation to form.
D)all of the above

Question 36

The mixing ratio is the most important of the moisture indices because:

A)it is the ratio of water vapor to a mass of dry air (as opposed to all air).
B)it is the ratio of water content to capacity.
C)it is the mass of water vapor relative to the mass of all other atmospheric gasses.
D)it is the ratio of water vapor to the volume of air involved.

Question 37

Relative humidity:

A)is a term rarely used by television weather forecasters.
B)is measured in grams per kilogram.
C)gives the percentage of water molecules in the air.
D)requires knowledge of the saturation specific humidity.

Question 38

Relative humidity is:

A)temperature dependent.
B)a measure of the content of water vapor compared to the capacity of an air sample.
C)usually higher at night than during the day.
D)may be substantially different from the humidity in a house.
E)all of the above

Question 39

Which of the following measures of humidity is not temperature-dependent?

A)specific humidity
B)absolute humidity
C)relative humidity
D)none of the above

Question 40

Relative humidity:

A)can change substantially during the course of a day.
B)depends on the actual amount of water vapor.
C)is independent of air temperature.
D)allows easy comparison of water vapor at different locations.

Question 41

If a relative humidity of 300 percent is necessary to ensure the long-term survival of a water droplet,then such a droplet would have a supersaturation of:

A)100 percent.
B)200 percent.
C)300 percent.
D)400 percent.

Question 42

When compared to a curved surface,saturation vapor pressures for water over a flat surface are:

A)equal.
B)more.
C)less.
D)not comparable.
E)none of the above

Question 43

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.

Question 44

Curved water surfaces:

A)have the same evaporative properties as do flat surfaces.
B)can require relative humidities greater than 100 percent.
C)have lower evaporation rates than do flat surfaces.
D)are rarely found in nature.

Question 45

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.

Question 46

The hair hygrometer:

A)uses hairs from dogs, usually golden retrievers.
B)takes advantage of the ability of hair to respond to changes in humidity.
C)was popular in the nineteenth century, but is no longer used today.
D)requires swinging the instrument around one's head for at least a minute.

Question 47

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 micrometeors from space.

Question 48

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.

Question 49

Steam fog would be most likely to occur in:

A)late fall and early winter.
B)late winter.
C)spring.
D)summer.

Question 50

This is the most common source of condensation nuclei in places like Pittsburgh and Cleveland:

A)human activities.
B)dust.
C)sea salt.
D)aerosols from fires.

Question 51

When the atmosphere contains more moisture than theoretically possible,the condition of ________ results.

A)curvature captivity
B)supersaturation
C)heterogeneous nucleation
D)nuclei exclusion

Question 52

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.

Question 53

A continuous record of temperature and humidity can be obtained by using a

A)aspirated psychrometer.
B)barograph.
C)wet/dry bulb thermometer system.
D)hygrothermograph.

Question 54

The wet bulb depression depends on:

A)air pressure.
B)air temperature.
C)air moisture content.
D)air composition.

Question 55

Water that is below 0 degrees Centigrade is called:

A)ice.
B)snow.
C)supercooled water.
D)sleet.

Question 56

Heterogeneous nucleation:

A)cannot occur in the presence of hygroscopic particles.
B)can only occur at humidities in excess of 100 percent.
C)results in a water droplet that is 100 percent water.
D)requires condensation nuclei.

Question 57

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.

Question 58

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.

Question 59

This is not one of the three processes for saturating air with water vapor:

A)increasing the carbon dioxide content of air.
B)adding water vapor to the air.
C)lowering the temperature to the dew point.
D)mixing cold air with warm, moist air.

Question 60

Ice nuclei:

A)are particularly abundant in the lower levels of the troposphere.
B)rarely have six sides.
C)have a better chance of forming ice at temperatures below -10 degrees Celsius.
D)begin to serve their function once the temperature falls to 0 degrees Celsius.

Question 61

Advection fog:

A)is responsible for the Tule fog of the Central Valley of California.
B)occurs when warm air passes over a cool surface.
C)rarely travels more than 100 meters from its point of origin.
D)is the result of adiabatic cooling.

Question 62

Sometimes fog will form over the pavement after a summer rain shower.What type of fog is this?

Question 63

Explain why a substantial increase in the amount of water vapor occurs in the United States during the summer months.

Question 64

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.

Question 65

If air starts out with a temperature of 18oC with a dew point of 10oC,an ascent of ________ is necessary for the air to become saturated.

A)500 m
B)800 m
C)1000 m
D)1200 m

Question 66

If an unsaturated air parcel with a temperature of 20oC rises,forms a non-precipitating cloud,then returns to its original altitude,

A)the parcel's final temperature will be less than 20 oC
B)the parcel's final temperature will be exactly 20 oC
C)the parcel's final temperature will be greater than 20 oC

Question 67

Clouds:

A)result from the warming or rising air parcels.
B)continue to form new droplets at least 500 meters above the lifting condensation level.
C)are not affected by the dew point lapse rate.
D)will eventually disappear through lack of lift and condensation.

Question 68

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

Question 69

This is the most important process of cloud formation:

A)sublimation of glaciers.
B)atmospheric cooling.
C)the absorption of infrared radiation by water vapor.
D)advection fog.

Question 70

Which of the following is not a factor in determining the amount of water vapor at one specific point in the atmosphere?

A)local evaporation
B)horizontal transport of moisture
C)aerosol concentration
D)vertical transport of moisture

Question 71

This type of fog is NOT the result of air cooling to the dew point:

A)radiation fog.
B)advection fog.
C)upslope fog.
D)steam fog.

Question 72

When air within a cloud begins to sink,it

A)cools at the dry adiabatic lapse rate
B)warms at the dry adiabatic lapse rate
C)cools at the saturated adiabatic lapse rate
D)warms at the saturated adiabatic lapse rate

Question 73

Clouds represent ________ motion occurring in the atmosphere.

Question 74

Frozen dew:

A)coalesces as ice crystals on surfaces.
B)is easy to remove from a windshield.
C)is more dangerous than frost.
D)is milky in color.

Question 75

Moist air from the Gulf of Mexico moves west toward the Rocky Mountains,forming ________ fog.

Question 76

If an unsaturated air parcel with a temperature of 20oC rises,forms a precipitating cloud,then returns to its original altitude,

A)the parcel's final temperature will be different than 20 oC
B)the parcel's final temperature will be exactly 20 oC
C)the parcel will never return to the surface
D)the parcel will continue rising until it reaches the tropopause

Question 77

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.

Question 78

Condensation of water onto your bathroom mirror while you shower is an example of

A)saturation caused by adding water vapor to the air
B)saturation caused by mixing cold air with warm, moist air
C)saturation caused by lowering the temperature to the dew point

Question 79

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.

Question 80

If water vapor is an invisible gas,then how can satellite images show the distribution of water vapor in the atmosphere?