module 6

What happens if the temperature of a parcel of air exceeds the temperature of its environment? The parcel will being to rise The parcel will stay still The parcel will dissolve in to other air parcels Stability will increase

The parcel will being to rise

A parcel of air expands and cools, or compresses and warms, with no interchange of heat with its outside surroundings. What is this called? isothermal ascent adiabatic process forced lifting advection

adiabatic process

The atmosphere is more stable if the air: at higher elevations is warmed, or the air closer to the surface cool. temperature changes linearly with height. at higher elevations is cooler, or the air closer to the surface warm. at higher elevations is same temperature as the air closer to the surface.

at higher elevations is warmed, or the air closer to the surface cool.

An inversion represents an extremely stable atmosphere because ____. air becomes cooler with height surface air becomes warmer than air aloft inversions act as a lid on vertical air motion inversions allow air pollutants to escape freely from surface air

inversions act as a lid on vertical air motion

For rainfall, we measure ________________ and for snow we measure ________________ to get the storm's intensity. rain per hour; snow per hour amount of rain; amount of snow visibility; rate of snow rainfall rate; visibility

rainfall rate; visibilityrainfall rate; visibilityrainfall rate; visibility

What process allows for droplets to grow in size in mixed clouds (warm and cold clouds)? Hadley formation Bergeron process Fourier transforms ITCZ oscillationvv

Bergeron process

Falling raindrops are tear-shaped because that is the profile that minimizes air resistance. True False

false

Cloud seeding using silver iodide may enhance precipitation in ____. cold clouds composed entirely of ice crystals warm clouds composed entirely of water droplets supercooled clouds containing a low ratio of ice crystals to droplets cumuliform clouds

supercooled clouds containing a low ratio of ice crystals to droplets

The ice crystal process of precipitation formation operates in the mixed ice and water region of a cold cloud where there are ice crystals and ____. supercooled droplets updrafts and downdrafts cloud condensation nuclei positive and negative electrical charges

supercooled droplets

A parcel's buoyancy is related to: Temperature. Moisture availability. Evaporation rates. Wind direction.

temperature

The dry adiabatic rate is the rate at which ____. an air parcel rises temperature changes in a rising or descending parcel of unsaturated air volume changes when a parcel expands or is compressed latent heat energy is released in a rising air parcel

temperature changes in a rising or descending parcel of unsaturated air

Adiabatic warming occurs when an air parcel sinks. True False

true

Air parcels are 'bubbles of air' that (1) are flexible, (2) have impermeable surfaces, and (3) have a uniform temperature and moisture content. True False

true

Higher precipitation intensity leads to higher reflectivity to a radar station. True False

true

In above-freezing air, cloud droplets can grow larger as faster-falling, bigger droplets collide and coalesce with smaller droplets in their path. True False

true

In the Bergeron-Wagener Process, ice crystals grow at the expense of water droplets. True False

true

Positive buoyancy of an air mass can lead to instability. True False

true

Powerful updrafts are main component in hail formation. True False

true

The environmental lapse rate is calculated outside of a parcel of air. True False

true

The shape of clouds forming is a sign of stability or instability in the atmosphere. True False

true

Visibility generally improves after a rain storm. True False

true

Which type of air parcel (unsaturated or saturated) loses temperature more quickly with elevation in the atmosphere? saturated Neither, because saturation does not affect the rate of cooling. unsaturated

unsaturated

In ____________, small cloud droplets join together through random times when they hit each other. coalescence morphing collision scattering

collision

The elevation above the surface where a cloud first forms is called the ____. level of free convection condensation level evaporation level adiabatic zone

condensation level

Which set of conditions, working together, will make the atmosphere the most stable? cooling the surface and warming the air aloft cooling the surface and cooling the air aloft warming the surface and cooling the air aloft warming the surface and warming the air aloft

cooling the surface and warming the air aloft

Suppose rain falls on one side of a street and not on the other side. This rain most likely fell from a ____ cloud. nimbostratus stratus cumulonimbus altostratus

cumulonimbus

The lightest form of rain is: virga. drizzle. cloudburst. shower.

drizzle

The atmosphere is normally most stable in the ____________ and most unstable in the ____________. early morning; afternoon early afternoon; morning late evening; late afternoon late morning; early evening

early morning; afternoon

Which of the following conditions would be described as the most unstable? isothermal (constant with height) conditions an inversion environmental lapse rate is 11° C per kilometer environmental lapse rate is 3° C per kilometer

environmental lapse rate is 11° C per kilometer

The rate at which the actual air temperature changes with increasing height above the surface is referred to as the: thermocline. moist adiabatic rate. environmental lapse rate. dry adiabatic rate.

environmental lapse rate.

Air parcels have the same characteristics as the surrounding environments. True False

false

All raindrops are spherical. True False

false

Hail can fall from both cumulonimbus and nimbostratus clouds. True False

false

Precipitation is the most important source of water vapor in the atmosphere. True False

false

Sleet can form after it hits the ground if the ground is cold enough. True False

false

Stability is a property of an air parcel, not of the atmosphere. True False

false

The air temperature in a rising parcel of saturated air decreases at the dry adiabatic rate, whereas the air temperature in a rising parcel of unsaturated air decreases at the moist adiabatic rate. True False

false

The atmosphere can be stable for saturated air, but not for unsaturated air at the same time. True False

false

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? snow hail freezing rain sleet

freezing rain

In a conditionally unstable atmosphere, the environmental lapse rate will be ____ than the moist adiabatic rate and ____ than the dry adiabatic rate. greater; less greater; greater less; greater less; less

greater; less

The combination of drifting and blowing snow, after falling snow has ended, is called a _____. true blizzard ground blizzard snow squall snow flurry

ground blizzard

The water droplet and the ice crystal in the figure above have the same temperature. The saturation vapor pressure surrounding the water droplet will be ___________ the saturation vapor pressure surrounding the ice crystal. higher than lower than the same as

higher than

Aircraft icing would be heaviest and most severe ____ freezing temperatures. in a cloud at warmer than in a cloud at just below in a cloud at well below outside a cloud at below

in a cloud at just below

Where would you expect to find a rain shadow? windward side of a mountain windward side of a tropical rainforest mountain top leeward side of a mountain

leeward side of a mountain

The moist adiabatic rate is ____ than the dry adiabatic heat because latent heat is ____ the rising air. less; removed from greater; removed from greater; added to less; added to

less; added to

Which of the environmental temperature profiles above indicates the most stable atmosphere? Line "A" Line "B" Line "C" Line "D"

line d

The atmosphere becomes _____ stable as the surface air cools, the air aloft warms, or a layer of air sinks over a vast area. more less pseudo-

more

What feature is in almost always involved with areas in the snowiest parts of the United States? forest land mountains oceans flat surfaces

mountains

The atmosphere is __________________ if an air parcel stays still. neutral unstable stable stochastic

neutral

Orographic clouds form ____. over a warm ocean current on the windward slope of a mountain behind a jet airplane by surface heating

on the windward slope of a mountain

Doppler radar, alone, can measure: cloud movement. precipitation type. rain intensity. cloud size.

rain intensity.

The intensity for _____ is measured by rate and the intensity for _____ is measured by visibility. rain; snow snow; rain hail; rain snow; hail

rain; snow

Subsidence inversions are best developed in high pressure areas because the ____ air associated with them causes the air to ____. rising; cool sinking; cool rising; warm sinking; warm

sinking; warm

A raindrop or partially melted snowflake that freezes into a pellet of ice in a deep subfreezing layer of air near the surface is called: snow. sleet. hail. freezing rain.

sleet

A raindrop that freezes before reaching the ground is called ____. snow graupel sleet glaze

sleet

If precipitation is frozen from the point when it leaves the cloud to when it hits the ground, it is called ___________________. freezing fog snow sleet freezing rain

snow

Sleet forms when: snow falls, then melts on the way down and freezes again. rain falls and freezes halfway down. snow falls then melts on the way down.

snow falls, then melts on the way down and freezes again.

The solid equivalent of drizzle is called ____. snow pellets hail snow grains rime

snow grains

Graupel is: another word for sleet. soft hail. hard ice. frozen rain.

soft hail.

If an air parcel is given a small push upward and it falls back to its original position, the atmosphere is said to be ____. stable unstable isothermal adiabatic

stable

If an air parcel is given a small push upward and it falls back to its original position, the atmosphere is said to be: stable. isothermal. adiabatic. unstable.

stable

A conditionally unstable atmosphere is ____ with respect to unsaturated air and ____ with respect to saturated air. unstable; stable unstable; unstable stable; unstable stable; stable

stable; unstable

A conditionally unstable atmosphere is _______ with respect to unsaturated air and _______ with respect to saturated air. stable; unstable unstable; unstable stable; stable unstable; stable

stable; unstable

Which cloud type would most likely form in absolutely stable air? cumulus congestus cumulonimbus stratus altocumulus

stratus

If you observe large raindrops hitting the ground, you could probably say that the cloud overhead was _______ and had _______ updrafts. thin; strong thick; strong thick; weak thin; weak

thick; strong

If an air parcel is given a small push upward and it continues to move upward on its own accord, the atmosphere is said to be ____. stable unstable buoyant dynamic

unstable

The atmosphere is __________________ if an air parcel accelerates upward. unstable stable neutral moist

unstable

A knowledge of air stability is important because it determines the: direction of movement of storms. seasonal weather patterns. movement of high pressure areas. vertical motion of air.

vertical motion of air.

An adiabatic process is one that occurs: with transfer of heat or matter between a system and its surroundings. without transfer of heat or matter between a system and its surroundings. without transfer of heat, but transfer of matter between a system and its surroundings. with transfer of heat, but no transfer of matter between a system and its surroundings.

without transfer of heat or matter between a system and its surroundings.

10 inches of snow is equal to __________ of liquid equivalent rainfall. 5 inches 3.3 inches 10 inches 1 inch

1 inch

Temperatures in a rising parcel of air are shown at various altitudes in the image above. Given that the dry adiabatic lapse rate is 10° C / 1 kilometer and the moist adiabatic lapse rate is 6° C / 1 kilometer, the data indicates that a cloud must have formed at: 3 kilometers. 1 kilometer. 4 kilometers. 2 kilometers.

1 kilometer.

An unsaturated parcel of air at the surface records a temperature of 27 ℃elsius. The parcel of air is raised to a new height of 5,000 meters and along its path reaches its Lifted Condensation Level at 2,000 meters. What do we expect the air parcel's temperature (in Celsius) to be at the following heights? Tip: The order might not be the same as in your worksheet as D2L randomizes match questions. Tip: Record to the nearest whole number. 1. 4,000 meters 2. 5,000 meters 3. 2,000 meters 4. 1,000 meters 5. 3,000 meters

1. -5 2. -11 3. 3,000 4. 17 5. 1

1. 3.0 inches of snow 2. 0.4 inches of liquid equivalent rainfall 3. 17.0 inches of snow 4. 0.2 inches of liquid equivalent rainfall 5. 5.0 inches of snow 6. 0.1 inches of liquid equivalent rainfall

1. = 0.3 inches of liquid equivalent rainfall 2. = 4.0 inches of snow 3. = 1.7 inches of liquid equivalent rainfall 4. = 2.0 inches of snow 5. = 0.5 inches of liquid equivalent rainfall 6. = 1.0 inches of snow

The following profiles of the atmosphere show the moist adiabat (blue line), the dry adiabat (red line), and the environmental lapse rate (dotted green line). Label each of the following profiles as being absolutely stable, absolutely unstable, or conditionally unstable. Click here for a larger view of the figure. Tip: The order might not be the same as in your worksheet as D2L randomizes match questions. = Absolutely Unstable = Conditionally Unstable = Absolutely Stable

1. Profile 1 (moist on the right, dry in the middle, ELR on left) 2. Profile 2 (moist on left, ELR middle, dry left) 3. Profile 3 (ELR on right, moist in middle, dry on left)

Rank the following types of precipitation sizes in order from the smallest to largest:rain, hail, drizzle, graupel, and mist. hail graupel mist rain drizzle

1. mist 2. drizzle 3. rain 4. graupel 5. hail

On average, the water equivalent of a typical fresh snowpack is ____. 1:1 5:1 10:1 20:1

10:1

If a parcel of unsaturated air with a temperature of 30° C rises from the surface to an altitude of 1,000 meters, the unsaturated parcel temperature at this altitude would be about: 10° C warmer than at the surface. 6° C colder than at the surface. 10° C colder than at the surface.

10° C colder than at the surface.

Which environmental lapse rate represents the most unstable condition in a layer of unsaturated air? 3°C per 1000 m 6°C per 1000 m 9°C per 1000 m 11°C per 1000 m

11°C per 1000 m

The Moist Adiabatic Lapse Rate occurs at what rate? 6.0 degrees C per 1000 meters 8.9 degrees C per 100 meters 5.5 degrees C per 1000 meters 3.3 degrees C per 10000 meters

6.0 degrees C per 1000 meters

Explain how a rain shadow forms.

A rain shadow forms on the leeward side of a mountain where precipitation is noticeably low, and the air is often drier. The rain shadow forms on the leeward side of the mountain after winds force air up on the windward side, where air cools, and moisture condenses, producing precipitation. As air moves down the leeward side, it warms and dries, producing less precipitation and desert-like conditions, thus forming a rain shadow.

What is precipitation? Water, either a solid, liquid or gas that falls from the sky Any solid or liquid water that falls from the atmosphere that hits the ground Water that hits the ground Only rain or snow

Any solid or liquid water that falls from the atmosphere that hits the ground

How do raindrops form in warm clouds? Collision and coalescence Morphing and absorption Scattering and transmission Collision and morphing

Collision and coalescence

Compared to conventional radar, what additional capabilities does Doppler radar have? It can measure the temperature of cloud tops. It can provide a vertical view of a cloud's droplets and ice particles. It can measure the speed at which falling rain is moving vertically. It can measure the speed at which falling rain is moving horizontally.

It can measure the speed at which falling rain is moving horizontally.

When the atmosphere is stable, what is happening? Parcels of air are not rising Parcels of air are mixing Parcels of air are rising Parcels of air are becoming buoyant

Parcels of air are not rising

What do you need for the moist adiabatic lapse rate? Saturated air Windy conditions Temperature inversion Unsaturated air

Saturated air

Why is snow challenging to measure? Snowy areas are too inaccessible to measure. Snow accumulations vary greatly from one spot to the next. Snow accumulation rates are too fast for traditional gauges. Snow is too difficult to block wind around gauges.

Snow accumulations vary greatly from one spot to the next.

What do you need for the dry adiabatic lapse rate? Unsaturated air Windy conditions Temperature inversion Saturated air

Unsaturated air

What does atmospheric stability concern? Vertical motion in the atmosphere. Relative movement of synoptic air masses. Circulation of moisture in the upper atmosphere. Likelihood of tornado activity in an area.

Vertical motion in the atmosphere.

The most common snowflake form is ____. graupel a dendrite rime a splinter

a dendrite

Stability in the atmosphere is determined by comparing the temperature of __________ to the temperature of __________. thermals; condensation nuclei a sinking air parcel; the surrounding fog an air parcel; an environmental sounding a rising air parcel; its surrounding environment

a rising air parcel; its surrounding environment

Which cloud type below will only produce precipitation by the collision-coalescence process? a thick, cold nimbostratus cloud a thick, warm cumulus cloud a thick, cold cumulus cloud a thick, supercooled cumulonimbus cloud

a thick, warm cumulus cloud

If a rising, unsaturated air parcel is colder and heavier than the air surrounding at all levels, the atmosphere is ____. conditionally unstable absolutely stable absolutely unstable neutrally stable

absolutely stable

Suppose the rising air parcel is warmer and less dense than the air around it. In this case, the atmosphere is ____. absolutely stable absolutely unstable convectively unstable conditionally unstable

absolutely unstable

In _______________, ice crystals 'sweep up' supercooled water droplets to grow in size. collision accretion aggregation coalescence

accretion

In ________________, ice crystals join together through random times when they hit each other. coalescence aggregation accretion morphing

aggregation

There are two processes responsible for the formation of precipitation in cold clouds: aggregation and accretion. collision and accretion. collision and coalescence. aggregation and coalescence.

aggregation and accretion.

The process by which ice crystals collide and form a single larger ice particle is called: augmentation. coalescence. aggregation. accretion.

aggregation.

Which of the following sets of conditions would produce a cumulus cloud with the lowest base? air temperature 90° F, dew point temperature 60° F air temperature 90° F, dew point temperature 50° F air temperature 9° F, dew point temperature 20° F air temperature 90° F, dew point temperature 40° F

air temperature 90° F, dew point temperature 60° F

The dry adiabatic lapse rate is __________ greater than the moist adiabatic lapse rate. sometimes never occasionally always

always

Radar gathers information about precipitation in clouds by measuring the ____. energy emitted by the precipitation particles absorption characteristics of falling precipitation amount of energy reflected back to a transmitter amount of sunlight scattered off the precipitation

amount of energy reflected back to a transmitter

Most rain at middle latitudes is produced by the ice crystal process. This is because ____. clouds in these region have below-freezing temperatures at all levels but experience strong uplifts clouds in these regions can extend into regions where air temperatures are below freezing ice crystals evaporate more slowly than water droplets in clouds of these regions most rain occurs during the winter in these regions

clouds in these regions can extend into regions where air temperatures are below freezing

In _______________, small cloud droplets join together larger droplets overtaking smaller droplets. morphing coalescence scattering collision

coalescence