Deck 5: Condensation - Dew - Fog - and Clouds

Question 1

​Water vapor cannot condense onto hygroscopic nuclei particles at relative humidities less than 100 percent.

Answer 1

False

Question 2

Even at high elevations where cirrus clouds are found, liquid water still exists in the clouds.

Answer 2

True

Question 3

​On a cold morning, it is possible to see your breath even if the air temperature is above freezing.

Answer 3

True

Question 4

​Wet haze restricts visibility more than dry haze.

Question 5

​Contrails form due to the heating of air by aircraft engine exhaust.

Question 6

​Steam fog poses a threat to humans with respiratory problems.

Question 7

​The cooling of the ground to produce dew is mainly the result of

A) ​conduction.
B) ​radiational cooling.
C) ​cooling due to the release of latent heat.
D) ​advection.
E) ​condensation.

Question 8

​Aside from cumulonimbus clouds that sometimes penetrate into the stratosphere, all clouds are observed in the lower atmosphere.

Question 9

​Fog is a major hazard to aviation.

Question 10

​The foggiest spot near sea level in the United States is Cape Cod, Massachusetts.

Question 11

​In hazy conditions, distant objects are usually more visible in the afternoon than in the morning, even when the concentration of particles in the air has not changed.

Question 12

​All clouds form in rising air.

Question 13

​High cirriform clouds are composed almost entirely of ice crystals. In tropical regions, air temperatures low enough to freeze all liquid water usually occur only above 6000 m (about 20,000 ft). In polar regions, however, these same temperatures may be found at altitudes as low as 3000 m (about 10,000 ft). Hence, while you may observe cirrus clouds at 3600 m (about 12,000 ft) over northern Alaska, you will not see them at that elevation above southern Florida.

Question 14

​Dew is most likely to form on

A) ​clear, calm nights.
B) ​cloudy, calm nights.
C) ​clear, windy nights.
D) ​cloudy, windy nights.
E) ​rainy nights.

Question 15

​Because fog causes a lot of problems, such as accidents, scientists are seeking ways to disperse, or at least "thin" fog.

Question 16

​Frost forms when the dew point temperature is at or below freezing.

Question 17

​The sky is overcast and it is raining. The cloud above you is a cumulus humilis cloud.

Question 18

​The TRMM (Tropical Rainfall Measuring Mission) satellite, a joint venture between NASA and the Japan Aerospace Exploration Agency, can pick out individual cloud features as small as 2.4 km (1.5 mi) in diameter.

Question 19

​In Ralph Abercromby's and Hugo Hildebrandsson's cloud classification system, each of the four primary cloud groups is identified by the type of precipitation it produces.

Question 20

​Condensation nuclei may be made up of salt from the ocean.

Question 21

​Thick clouds of this type can be used to predict rain or snow within 12 to 24 hours because the often appear ahead of an advancing cyclonic storm.

A) ​stratus
B) ​nimbostratus
C) ​cirrostratus
D) ​stratocumulus
E) ​altocumulus

Question 22

​When radiation fog "burns off", the fog tends to dissipate

A) ​from the bottom up.
B) ​from the top down.
C) ​starting at the middle and working both upward and downward.
D) ​laterally.
E) ​in random directions.

Question 23

​Detached clouds of delicate and fibrous appearance, without shading, usually white in color and sometimes of a silky appearance are

A) ​stratus clouds.
B) ​cirrocumulus clouds.
C) ​altostratus clouds.
D) ​cirrus clouds.
E) ​cirrostratus clouds.

Question 24

​These types of clouds make the Sun appear as a dimly visible round disk.

A) ​altocumulus
B) cirrostratus
C) ​altostratus
D) ​cirrocumulus
E) ​cirrus

Question 25

​Light or moderate-but-steady precipitation is most often associated with ____ clouds.

A) ​nimbostratus
B) ​cirrostratus
C) ​cirrocumulus
D) ​cumulonimbus
E) ​altocumulus

Question 26

​A dim, "watery" Sun visible through a gray sheet-like cloud layer is often a good indication of ____ clouds.

A) ​stratocumulus
B) cirrostratus
C) ​cumulonimbus
D) ​altostratus
E) ​nimbostratus

Question 27

​Fog that most often forms as warm rain falls into a cold layer of surface air is called

A) ​radiation fog.
B) ​evaporation (mixing) or frontal fog.
C) ​advection fog.
D) ​upslope fog.
E) ​giant fog.

Question 28

​If fog is forming in Denver, Colorado (located on the eastern side of the Rocky Mountains), and the wind is blowing from the east, then the fog is most likely

A) ​advection fog.
B) ​frontal fog.
C) ​upslope fog.
D) ​radiation fog.
E) ​downslope fog.

Question 29

​Radiation fog forms best on a

A) ​clear winter night with a slight breeze.
B) ​cloudy winter night with a strong breeze.
C) ​clear summer night with a strong breeze.
D) ​cloudy summer night with a slight breeze.
E) ​cloudy winter night with a slight breeze.

Question 30

​An anvil-shaped top is most often associated with

A) ​cumulonimbus.
B) ​cumulus congestus.
C) ​altocumulus.
D) ​cumulus humilis.
E) ​stratus.

Question 31

​When viewed from the surface, these clouds may be viewed as individual cloud elements (puffs) or as rows of ripples that resemble the scales of a fish.

A) ​stratocumulus
B) ​cumulus
C) ​cirrocumulus
D) ​altocumulus
E) ​cumulonimbus

Question 32

​Frost typically forms on the inside of a windowpane (rather than the outside) because

A) ​the inside of the pane is colder than the outside.
B) ​there is more water vapor touching the inside of the pane.
C) ​there is less water vapor touching the inside of the pane.
D) ​the temperature is higher on the inside.
E) ​there is more radiational cooling on the inside.

Question 33

​Clouds are classified by their

A) ​appearance.
B) ​altitude.
C) ​method of formation.
D) ​temperature.
E) ​altitude and appearance.

Question 34

​On a cold, winter morning, the most likely place for radiation fog to form is

A) ​at the top of a hill or mountain.
B) ​in a valley.
C) ​along the side of a hill.
D) ​over a body of water.
E) ​in a city.

Question 35

​Cirrus clouds are composed primarily of

A) ​water droplets.
B) ​water vapor.
C) ​ice particles.
D) ​salt aerosols.
E) ​dust particles.

Question 36

​The fog that forms along the Pacific coastline of North America is mainly of which type?

A) ​radiation fog
B) ​upslope fog
C) ​frontal fog
D) ​advection fog
E) ​steam fog

Question 37

​Condensation nuclei are important in the atmosphere because

A) ​they provide most of the minerals found in water.
B) ​they make it easier for condensation to occur in the atmosphere.
C) ​they are the sole producers of smog.
D) ​they filter out sunlight.
E) ​they provide the only means we have of tracking wind motions.

Question 38

​Particles that serve as surfaces on which water vapor may condense are called

A) ​hydrophobic nuclei.
B) ​nacreous nuclei.
C) ​condensation nuclei.
D) ​scud.
E) ​molecules.

Question 39

​A low, lumpy cloud layer that appears in rows, patches, or rounded masses would be classified as

A) ​nimbostratus.
B) ​stratus.
C) ​altocumulus.
D) ​stratocumulus.
E) ​cirrostratus.

Question 40

​Which cloud type is composed of ice crystals and can cause a halo to form around the Sun or Moon?

A) ​altostratus
B) ​stratus
C) ​nimbostratus
D) ​cirrostratus
E) ​angelitus

Question 41

​Satellite images taken of clouds at night use

A) ​reflected visible radiation.
B) ​reflected infrared radiation.
C) ​emitted infrared radiation.
D) ​microwave radiation.
E) ​emitted ultraviolet radiation.

Question 42

​As Apollo 12 ascended into the atmosphere, the height of the surrounding clouds was noted to be 42,000 feet. A lightning strike was seen within these clouds, indicating that they must have been

A) ​cumulus congestus.
B) ​cumulonimbus.
C) ​cirrus.
D) ​cirrocumulus.
E) ​lenticular.

Question 43

​Hail is usually associated with ____ clouds.

A) ​stratus
B) ​cumulus
C) ​stratocumulus
D) ​altocumulus
E) ​cumulonimbus

Question 44

​The cloud with the greatest vertical growth is

A) ​cumulus congestus.
B) ​cumulus humilis.
C) ​cumulonimbus.
D) ​cirrocumulus.
E) ​altocumulus.

Question 45

​In Howard's cloud classification system sheetlike clouds were named ____ ("layer"); a puffy cloud ____ ("heap"); a wispy cloud ____ ("curl of hair"); and a rain cloud ____ ("violent rain").

A) ​cirrus; cumulus; stratus; nimbus
B) ​cirrus; nimbus; stratus; cumulus
C) ​stratus; cumulus; cirrus; nimbus
D) ​stratus; nimbus; cirrus; cumulus
E) ​cumulus; cirrus; stratus; nimbus

Question 46

​On an ordinary day, a volume of air about the size of your index finger contains between ____ and ____ particles.

A) ​1; 150
B) ​10; 1,500
C) ​100; 15,000
D) ​1,000; 150,000
E) ​10,000; 1,500,000

Question 47

​Near the shore of an extremely large lake, steam fog is more likely to form during the ____ and advection fog in early ____.

A) ​spring; summer
B) ​summer; winter
C) ​winter; summer
D) ​winter; autumn
E) ​autumn; spring

Question 48

​Suppose two ocean currents with different temperatures are flowing next to one another. If the wind blows perpendicular to the currents, we would expect to find

A) ​radiation fog.
B) ​steam fog.
C) ​lenticular clouds.
D) ​advection fog.
E) ​haze.

Question 49

​Radiation fog typically forms on

A) ​clear, calm days.
B) ​clear, windy days.
C) ​clear, calm nights.
D) ​clear, windy nights.
E) ​any day and in any conditions.

Question 50

​Advection fog is often observed along the Pacific coast during summer, as westerly winds carry moist air toward the shore. The fog forms because the surface water near the coast is ____ the surface water farther offshore.

A) ​much colder than
B) ​much warmer than
C) ​the same temperature as
D) ​richer in nutrients than
E) ​richer in wildlife than

Question 51

​Which cloud forms in descending air?

A) ​cumulus fractus
B) ​cumulonimbus
C) ​mammatus
D) ​pileus
E) ​cirrus

Question 52

​Which two clouds can produce precipitation?

A) ​cumulonimbus and stratocumulus
B) ​nimbostratus and altostratus
C) ​nimbostratus and cirrus
D) ​cumulonimbus and nimbostratus
E) ​cirrus and stratocumulus

Question 53

​In 1803, Luke Howard, an English naturalist, developed a cloud classification system that employed ____ words to describe clouds as they appear to a ground observer.

A) ​German
B) ​Greek
C) ​Spanish
D) ​English
E) ​Latin

Question 54

​The dew point is the temperature at which

A) ​water starts to boil.
B) ​fog changes into haze.
C) ​high clouds form.
D) ​freezing occurs.
E) ​saturation occurs.

Question 55

​Upslope fog forms because air ____ as it flows up a hill or mountain range.

A) ​warms adiabatically
B) ​warms radiatively
C) ​cools adiabatically
D) ​cools radiatively
E) ​remains at the same temperature

Question 56

​Nuclei with a radius of less than 0.1 µm are referred to as ____ nuclei.

A) ​Aitken
B) ​condensation
C) ​hygroscopic
D) ​giant
E) ​hydophobic

Question 57

​Fog that forms in industrial areas is usually quite thick because the pollution particles provide large numbers of ____ nuclei on which water droplets can form.

A) ​hydrophobic
B) ​giant
C) ​salt crystal
D) ​haze
E) ​hygroscopic

Question 58

​In 1887, Ralph Abercromby and Hugo Hildebrandsson expanded Howard's original cloud classification system and published a classification system that, with only slight modification, is still in use today. In their system, ____ principal cloud forms are divided into ____ primary cloud groups.

A) ​eight; two
B) ​nine; three
C) ​ten; four
D) ​eleven; five
E) ​twelve; six

Question 59

​When temperatures are below freezing, the temperature to which air must be cooled in order for a phase change (from liquid to ice) to occur is called the

A) ​wet bulb.
B) ​dew point.
C) ​frost point.
D) ​heat index.
E) ​frost index.

Question 60

​The scattering effect of dry haze produces a ____ color when viewed against a dark background and a ____ tint when viewed against a light-colored background.

A) ​yellowish; bluish
B) ​bluish; yellowish
C) ​reddish; yellowish
D) ​yellowish; reddish
E) ​whitish; silvery

Question 61

​Noctilucent clouds, meaning "luminous night clouds" are best seen at ____, during the ____ at latitudes poleward of 50 degrees.

A) ​sunset; winter
B) ​sunrise; fall
C) ​sunrise; spring
D) ​twilight; winter
E) ​twilight; summer

Question 62

​Mammatus clouds most frequently form on the underside of ____ clouds.

A) ​cumuloaltus
B) ​stratus
C) ​cirrus
D) ​nimbostratus
E) ​cumulonimbus

Question 63

​____________________ fog forms when two unsaturated bodies of air mix and the resulting mixture is saturated.

Question 64

​One positive aspect of foggy weather is a process required by fruit and nut trees that have finished growing during the summer and fall. This process, called ____________________, is the number of hours with air temperature below 7^oC (45^oF) before trees will begin to grow again.

Question 65

​In regions where there are no clouds, it is difficult to observe the movement of air using satellite imaging. To help with this situation, geostationary satellites are equipped with ____ that can profile the distribution of atmospheric water vapor in the middle and upper troposphere.

A) ​special radiometers
B) ​water-vapor sensors
C) ​ultraviolet imaging sensors
D) ​computer enhancement software
E) ​reflected light imaging capabilities

Question 66

​As the air cools during the night, the relative humidity increases. When the relative humidity reaches about 75 percent, condensation may begin on the most active hygroscopic nuclei, producing a ____________________ haze.​

Question 67

​Oils, gasoline, and paraffins are examples of ____________________ nuclei.

Question 68

​The condensation nuclei most favorable for producing clouds (called cloud condensation nuclei) have radii of ____________________ µm or more.

Question 69

​You are sitting inside your house on a sunny afternoon. The shades are drawn and you look at the window and notice the Sun disappears for about 10 seconds. The alternate light and dark period lasts for nearly 30 minutes. The clouds passing in front of the Sun are ____________________ clouds.

Question 70

​Suppose it is raining lightly from a deck of nimbostratus clouds. Beneath the clouds are small, ragged, puffy clouds that are moving rapidly with the wind. These clouds would be called ____________________.

Question 71

​Nacreous clouds form in the ____.

A) ​troposphere
B) ​stratosphere
C) ​ionosphere
D) ​mesosphere
E) ​thermosphere

Question 72

​The process of water vapor changing directly to ice without becoming a liquid first is called ____________________.

Question 73

​In infrared-enhanced images, clouds with the coldest (highest) tops are typically assigned the colors ____ or ____.

A) ​black; dark grey
B) ​orange; yellow
C) ​light green; dark green
D) ​dark blue; red
E) ​light grey; white

Question 74

​To a weather forecaster a clear sky is one where no clouds are present. When there are between ____ and ____ clouds covering the sky, there are a few clouds present.

A) ​one-eighth; two-eighth
B) ​two-eighth; three-eighth
C) ​three-eighth; four-eighth
D) ​four-eighth; five-eighth
E) ​five-eighth; six-eighth

Question 75

​It is difficult to directly identify significant cloud and surface features on an infrared image when ____ differences are small.

A) ​relative humidity
B) ​air pressure
C) ​wind
D) ​precipitation
E) ​temperature

Question 76

​In 1802, the French naturalist ____________________ proposed the first system for classifying clouds.

Question 77

​____________________ fog is rare over tropical water.

Question 78

When surfaces such as twigs, leaves, and blades of grass cool below the saturation temperature, water vapor begins to condense upon them, forming tiny visible specks of water called ____________________. If the air temperature should drop to freezing or below, the ____________________ will freeze, becoming tiny beads of ice called ____________________.
​

Question 79

​A layer of dust or salt particles suspended above a region is called ____________________.

Question 80

​When a cloud forms over and extends downwind of an isolated mountain peak, it is called a ____ cloud.

A) ​lenticular
B) ​banner
C) ​cap
D) ​pileus
E) ​mammatus