WX 201 Exam 2 with correct Answers (Graded
A)
Generally, the concentration of condensation nuclei is greater over the oceans than over land.
False
If a city receives 24 inches of snow, it is the equivalent to 18 inches of rain.
False
An important factor in the production of rain by the collision-coalescence process is the number of ice
crystals in the cloud.
False
In a cloud composed of water droplets and ice crystals, the saturation vapor pressure is less over the
droplets than over the ice.
False
There are many types of precipitation. Let's think about the typical, however. A typical raindrop is
about ____ than a typical cloud droplet.
one hundred times larger
In the winter, you read in the newspaper that a large section of the Midwest is without power due to
downed power lines. Which form of precipitation would most likely produce this situation?
Freezing rain
Precipitation with the greatest size (diameter) is ____.
a hailstone
Which statement below best describes the curvature effect?
Reduced surface tension and the larger saturation vapor pressure required for the drop to remain in
equilibrium with its surroundings.
Condensation onto hygroscopic nuclei is possible at relative humidity less than 100 percent due to the
____.
solute effect
Found in certain regions of the cloud formation, a supercooled cloud droplet is ____.
a liquid droplet observed at temperatures below 0 degrees Celsius (32 degrees Fahrenheit)
Typical cloud droplets seldom reach the ground as rain because they evaporate before reaching the
ground.
True
Which below best describes the solute effect?
The water droplets dissolve hygroscopic nuclei and condensation can occur at relative humidity less
than 100 percent.
,Heavy showers usually fall from cumulus clouds, whereas steady precipitation normally falls from
stratus clouds.
True
Large, heavy snowflakes are associated with moist air and temperatures well below freezing.
False
Clouds are complex and can have different temperature zones. The region of a cloud where only ice
particles exist is called ____.
glaciated
Generally, the smaller the pure water droplet, the lower the temperature at which it will freeze.
True
The growth of a precipitation particle by the collision of an ice crystal (or snowflake) with a
supercooled liquid droplet is called ____.
accretion
While the diameter of raindrops can vary widely, most that reach Earth's surface are seldom larger
than ____ in diameter.
5 mm
The main difference between a cloud drop and a raindrop is its ____.
size
In a fact that surprises many people, small raindrops fall ____ large raindrops, and have ____ terminal
velocity than/as large raindrops.
slower than; a lesser
Atmospheric conditions that produce sleet differ from those that produce hail because for sleet to
form, surface temperatures must be below freezing, whereas surface temperatures are typically well
above freezing during hailstorms.
True
The speed of falling cloud droplet increases until the air resistance ____
equals the pull of gravity
Which of the following might be mistaken for hail because of its appearance and its origin?
Graupel
There are many types of clouds, but not all produce precipitation. Which cloud type will only produce
precipitation by the collision-coalescence process?
A thick, warm cumulus cloud.
, Rain that falls from a cloud but evaporates before reaching the ground is referred to as ____. One can
see streaks in the sky, and it often has a lovely color.
virga
Updrafts are responsible for the production of hail, while sleet is produced from a different process.
Raindrop production can be complex, particularly with the collision-coalescence process. If you
observe large raindrops hitting the ground, you could probably say that the cloud overhead was ____
and had ____ updrafts.
thick; strong
In a cloud over land, where the air temperature is -10 degrees Celsius, we would find many more
cloud droplets than ice crystals.
True
For sub-freezing temperatures, the saturation vapor pressure just above a liquid water surface is ____
the saturation vapor pressure above an ice surface.
greater than
A ____ change in pressure over a relatively short distance is called a steep pressure gradient.
rapid
A ____ is generally associated with trough on an upper level isobaric chart.
low pressure center
Because lows are also known as cyclones, the flow of air around them is often called anti-cyclonic
flow.
False
Isobaric surfaces are ____ in less-dense, warm air and ____ in cold, more-dense air.
higher; lower
In the middle latitudes, when an area of high pressure approaches a city, surface pressure usually
____. When it moves away, pressure usually ____.
rises; falls
Another term for isobaric chart is constant pressure chart.
True
Surface winds blow across isobars at an angle and the pressure gradient force is balanced by the ____
force and the Coriolis force.
frictional
The wind around a surface high pressure center in the Northern Hemisphere, blows ____ and
outward from the center.
clockwise
A)
Generally, the concentration of condensation nuclei is greater over the oceans than over land.
False
If a city receives 24 inches of snow, it is the equivalent to 18 inches of rain.
False
An important factor in the production of rain by the collision-coalescence process is the number of ice
crystals in the cloud.
False
In a cloud composed of water droplets and ice crystals, the saturation vapor pressure is less over the
droplets than over the ice.
False
There are many types of precipitation. Let's think about the typical, however. A typical raindrop is
about ____ than a typical cloud droplet.
one hundred times larger
In the winter, you read in the newspaper that a large section of the Midwest is without power due to
downed power lines. Which form of precipitation would most likely produce this situation?
Freezing rain
Precipitation with the greatest size (diameter) is ____.
a hailstone
Which statement below best describes the curvature effect?
Reduced surface tension and the larger saturation vapor pressure required for the drop to remain in
equilibrium with its surroundings.
Condensation onto hygroscopic nuclei is possible at relative humidity less than 100 percent due to the
____.
solute effect
Found in certain regions of the cloud formation, a supercooled cloud droplet is ____.
a liquid droplet observed at temperatures below 0 degrees Celsius (32 degrees Fahrenheit)
Typical cloud droplets seldom reach the ground as rain because they evaporate before reaching the
ground.
True
Which below best describes the solute effect?
The water droplets dissolve hygroscopic nuclei and condensation can occur at relative humidity less
than 100 percent.
,Heavy showers usually fall from cumulus clouds, whereas steady precipitation normally falls from
stratus clouds.
True
Large, heavy snowflakes are associated with moist air and temperatures well below freezing.
False
Clouds are complex and can have different temperature zones. The region of a cloud where only ice
particles exist is called ____.
glaciated
Generally, the smaller the pure water droplet, the lower the temperature at which it will freeze.
True
The growth of a precipitation particle by the collision of an ice crystal (or snowflake) with a
supercooled liquid droplet is called ____.
accretion
While the diameter of raindrops can vary widely, most that reach Earth's surface are seldom larger
than ____ in diameter.
5 mm
The main difference between a cloud drop and a raindrop is its ____.
size
In a fact that surprises many people, small raindrops fall ____ large raindrops, and have ____ terminal
velocity than/as large raindrops.
slower than; a lesser
Atmospheric conditions that produce sleet differ from those that produce hail because for sleet to
form, surface temperatures must be below freezing, whereas surface temperatures are typically well
above freezing during hailstorms.
True
The speed of falling cloud droplet increases until the air resistance ____
equals the pull of gravity
Which of the following might be mistaken for hail because of its appearance and its origin?
Graupel
There are many types of clouds, but not all produce precipitation. Which cloud type will only produce
precipitation by the collision-coalescence process?
A thick, warm cumulus cloud.
, Rain that falls from a cloud but evaporates before reaching the ground is referred to as ____. One can
see streaks in the sky, and it often has a lovely color.
virga
Updrafts are responsible for the production of hail, while sleet is produced from a different process.
Raindrop production can be complex, particularly with the collision-coalescence process. If you
observe large raindrops hitting the ground, you could probably say that the cloud overhead was ____
and had ____ updrafts.
thick; strong
In a cloud over land, where the air temperature is -10 degrees Celsius, we would find many more
cloud droplets than ice crystals.
True
For sub-freezing temperatures, the saturation vapor pressure just above a liquid water surface is ____
the saturation vapor pressure above an ice surface.
greater than
A ____ change in pressure over a relatively short distance is called a steep pressure gradient.
rapid
A ____ is generally associated with trough on an upper level isobaric chart.
low pressure center
Because lows are also known as cyclones, the flow of air around them is often called anti-cyclonic
flow.
False
Isobaric surfaces are ____ in less-dense, warm air and ____ in cold, more-dense air.
higher; lower
In the middle latitudes, when an area of high pressure approaches a city, surface pressure usually
____. When it moves away, pressure usually ____.
rises; falls
Another term for isobaric chart is constant pressure chart.
True
Surface winds blow across isobars at an angle and the pressure gradient force is balanced by the ____
force and the Coriolis force.
frictional
The wind around a surface high pressure center in the Northern Hemisphere, blows ____ and
outward from the center.
clockwise
