Midterm Flashcards
1
Q
The international standard adopted for measurements is Universal Coordinated Time (UTC) is also known as:
a. Zulu Time (Z)
b. Daylight Time (DT)
c Greenwich Mean Time (GMT)
d. both a and c
A
both a and c
2
Q
If a map is created using data collected at 1400 UTC, December 4, what is the local date and time? (Answers below apply to the Central Time Zone of the USA)
a. 2pm Dec 4
b. 2am Dec 4
c. 8am Dec 4
d. 8pm Dec 4
e. 8pm Dec 3
A
c. 8am Dec 4
3
Q
The weather data used to compile surface maps are obtained primarily from what instruments?
(a) Doppler radars
(b) wind profilers
(c) rawinsondes
(d) Automated Surface Observing Systems (ASOS)
(e) Aeronautical Radio Inc., Communications Addressing and Reporting Systems (ACARS)
A
d. Automated Surface Observing Systems (ASOS)
4
Q
Which instrument collection system has the highest density network in the United States?
(a) rawinsondes
(b) wind profilers
(c) ASOS (Automated Surface Observing System)
(d) NLDN (National Lightning Detection Network)
A
c. ASOS (Automated Surface Observing System)
5
Q
Temperature, pressure, wind and moisture are measured through the depth of the troposphere by what instrument?
(a) rawinsonde
(b) wind profiler
(c) Doppler radar
(d) GOES satellite
A
a. rawinsode
6
Q
Of the instruments listed below, which instrument could not possibly have collected a vertical profile of the wind?
(a) Automated Surface Observing System
(b) Doppler Radar
(c) Wind Profiler
(d) Rawinsonde
A
a. Automated Surface Observing System
7
Q
Which of the following could not be measured by an Automated Surface Observing System (ASOS)?
(a) fog
(b) cloud height
(c) precipitation
(d) wind direction
(e) cloud top temperature
A
e. cloud top temperature
8
Q
What is the primary mechanism for obtaining surface data over oceans?
(a) ships
(b) weather buoys
(c) Automated Surface Observing System (ASOS)
(d) (a) and (b) are correct
(e) (a), (b) and (c) are correct.
A
d. a and b are correct
9
Q
What is the term used to describe the weather products that show how several atmospheric surface properties change with time
(a) sounding
(b) buoy plot
(c) meteogram
(d) radar display
A
c. meteogram
10
Q
Which of the following variables is not measured by a rawinsonde?
(a) temperature
(b) moisture content
(c) precipitation
(d) All of the above are measured using a rawinsonde.
A
c. precipitation
11
Q
Measurements of temperature, wind and relative humidity at various pressure levels in the atmosphere are made worldwide with balloon-borne instruments called rawinsondes. How frequently are these measurements typically made?
(a) every hour
(b) every 3 hours
(c) every 6 hours
(d) every 12 hours
A
d. 12 hours
12
Q
What is the name given to the final weather product created with data gathered from a rawinsonde?
(a) sounding
(b) meteogram
(c) surface analysis
(d) wind profiler data image
(e) weather balloon-o-gram
A
a. sounding
13
Q
What term is used to describe a layer in the atmosphere where atmospheric temperature increases with height?
(a) inversion
(b) lapse rate
(c) meteogram
(d) alternate slope
A
a. inversion
14
Q
Which of the following properties is measured by both a rawinsonde and a wind profiler that has a Radio Acoustic Sounding System (RASS)?
(a) pressure
(b) moisture
(c) visibility
(d) temperature
(e) None of the above are correct.
A
d. temperature
15
Q
If you wanted to estimate the intensity of precipitation, what weather product would you examine?
(a) atmospheric sounding
(b) radar reflectivity image
(c) radar radial velocity image
(d) satellite water vapor image
A
b. radar reflectivity image
16
Q
A Doppler radar can detect which of the following?
(a) the intensity of the precipitation
(b) the geographic location of the precipitation
(c) the motion of air toward and away from the radar in/near a storm
(d) (a) and (b) are correct; (c) is incorrect.
(e) (a), (b), and (c) are all correct.
A
e. a,b, and c are all correct
17
Q
Which of the following can be measured by a Doppler radar?
(a) The cloud top temperature.
(b) The speed of the wind toward or away from the radar.
(c) The atmospheric relative humidity in the vicinity of the radar.
(d) The atmospheric pressure in the vicinity of a severe storm.
(e) All of the above
A
b. the speed of the wind toward or away from the radar
18
Q
Which statement about Doppler radars and wind profilers is correct?
(a) Both can be used to determine a vertical profile of the wind.
(b) Total precipitation amounts can be determined by both instruments.
(c) Each instrument can produce vertical temperature profiles, just like a rawinsonde.
(d) They compliment each other because Doppler radars work best when precipitation is falling and profilers work best in clear air.
(e) (a) and (d) are both correct.
A
e. a and d are both correct
19
Q
You are the radar meteorologist using the WSR-88D display at the National Weather Service Forecast Office. What information can you obtain from it?
(a) You can use the radial velocity to determine if a thunderstorm is rotating.
(b) You can use the radar reflectivity to determine the location of thunderstorms.
(c) You can examine the “storm total precipitation” to identify where a flash flood may occur.
(d) Only (b) and (c) are correct.
(e) (a), (b) and (c) are all correct.
A
e. a,b and c are all correct
20
Q
A color scale is used to display the intensity of precipitation as measured by a Doppler radar. Which color indicates the heaviest precipitation rate?
(a) red
(b) blue
(c) black
(d) green
A
a. red
21
Q
During what decade were WSR-88D radars installed across the United States?
(a) 1960s
(b) 1970s
(c) 1980s
(d) 1990s
(e) 2000s
A
d. 1990s
22
Q
During what decade were satellites first used to acquire weather data in the United States?
(a) 1960s
(b) 1970s
(c) 1980s
(d) 1990s
(e) 2000s
A
(a) 1960s
23
Q
Which of the following is not a channel used by weather satellites in monitoring the weather?
(a) visible
(b) infrared
(c) ultraviolet
(d) water vapor
A
(c) ultraviolet
24
Q
Which of the following can the infrared satellite sensor on the GOES satellite measure?
(a) intensity of precipitation
(b) amount of vapor in the atmosphere
(c) surface dewpoint temperature
(d) temperature of cloud tops
A
(d) temperature of cloud tops
25
A cloud appears bright on a visible satellite image and dark on an infrared satellite image. Where is the top of this cloud likely to be located?
(a) near the surface (in the lower troposphere)
(b) near the tropopause (in the upper troposphere)
(c) above the tropopause (in the lower stratosphere)
(d) above the stratopause (in the lower mesosphere)
(a) near the surface (in the lower troposphere)
26
Which of the following statements about satellites is(are) true?
(a) Infrared satellite images show the temperature of the cloud tops.
(b) A satellite in geostationary orbit views the same region of Earth 24 hours a day.
(c) The vapor channel can identify regions of the atmosphere that are dry or moist because it is sensitive to the water vapor concentration.
(d) The visible channel observes frequencies of electromagnetic energy that our eyes can sense.
(e) All of the above are true.
(e) All of the above are true.
27
What is the amount of infrared energy sensed by a GOES satellite related to?
(a) The solar radiation reflected by the surface.
(b) The solar radiation absorbed by the surface.
(c) The emission of energy from only water molecules.
(d) The temperature of the highest surface (cloud top or ground) visible from the satellite.
d. The temperature of the highest surface (cloud top or ground) visible from the satellite.
28
Which of the following is most representative of what is displayed on an infrared GOES satellite image?
(a) density
(b) cloud top pressure
(c) cloud top temperature
(d) cloud top relative humidity
(e) all of the above
c. cloud top temperature
29
Geostationary weather satellites are placed in orbit over the equator at a distance of how many miles above the Earth’s surface?
(a) about 100 miles
(b) about 1000 miles
(c) about 22,000 miles
(d) 1000 to 5000 miles, depending on season.
(e) None of the above are correct.
c. about 22,000 miles
30
If you wanted to determine the extent of cloud cover over the United States at noon, Central Daylight Time in mid-summer, which weather product would you examine?
(a) sounding
(b) wind profiler data
(c) visible satellite image
(d) radar reflectivity image
c. visible satellite image
31
This satellite channel measures solar radiation reflected from the underlying surfaces.
(a) visible
(b) infrared
(c) water vapor
a. visible
32
Which satellite channel measures the temperature of the underlying surfaces?
(a) visible
(b) infrared
(c) water vapor
b. infrared
33
A(n) ________ image from the GOES satellite allows us to measure the amount of moisture in the atmosphere.
(a) visible
(b) infrared
(c) water vapor
c. water vapor
34
The brightest regions on a(n) __________ satellite image are associated with the coldest clouds or surfaces.
(a) visible
(b) infrared
(c) water vapor
b. infrared
35
The brightest regions on a(n) __________ satellite image are associated with snow cover and clouds .
(a) visible
(b) infrared
(c) water vapor
a. visible
36
USE TEMP CHART: Which city has the highest air temperature?
Tucson, AZ
37
USE TEMP CHART: Which city has the highest dew point temperature?
Dallas, TX
38
USE TEMP CHART: Which city has the highest saturation vapor pressure?
Tucson, AZ
39
USE TEMP CHART: Which city has the highest vapor pressure?
Dallas, TX
40
USE TEMP CHART: Which city has the highest relative humidity?
Bismark, SD
41
USE TEMP CHART: Which city has the lowest temperature?
Bismark, SD
42
USE TEMP CHART: Which city has the lowest dewpoint temperature?
Detroit, MI
43
USE TEMP CHART: Which city has the lowest saturation vapor pressure?
Bismark, SD
44
USE TEMP CHART: Which city has the lowest vapor pressure?
Detroit, MI
45
USE TEMP CHART: Which city has the lowest relative humidity?
Tucson, AZ
46
USE SOUNDING: What is the surface air temperature?
10 degrees celsius
47
USE SOUNDING: What is the surface pressure?
1000 mb
48
USE SOUNDING: What is the surface dewpoint temperature?
6 degrees Celsius
49
USE SOUNDING: What is the 850 mb dewpoint depression?
10C - (-5C) = 15C
50
USE SOUNDING: At what pressure level is the tropopause?
200 mb
51
USE SOUNDING: What is the speed of the strongest wind?
100 knots
52
USE SOUNDING: Which layer is a cloud layer above Green Bay? (Identify the layer by the pressure at the top and)
900-950mb= 50mb
53
USE SOUNDING: What is the wind speed and direction at 500 mb?
40 knot westerly winds
54
At what altitude are “surface” temperature observations made?
(a) at ground level
(b) 2 meters above the surface
(c) 10 meters about the surface
(d) at whatever altitude the instruments happen to be on that day
b. 2 meters above the surface
55
What is the term used to describe a coding system for displaying large amount of surface data on a weather map?
(a) contour
(b) data plot
(c) station model
(d) observation organization
c. station model
56
USE STATION MODEL: Examine the surface station model shown here. It is based in the US. What is the reported air temperature?
32 F
57
USE STATION MODEL: What was the reported dewpoint temperature?
31 F
58
USE STATION MODEL: What was the reported air pressure?
998.0 mb
59
USE STATION MODEL: What was the reported wind direction?
south
60
USE STATION MODEL: What was the reported wind speed?
5 knots
61
USE STATION MODEL: What significant weather was reported?
rain showers
62
USE STATION MODEL: What was the reported cloud cover?
overcast
63
Isobars on a surface map represent constant values of which variable?
(a) wind speed
(b) temperature
(c) station pressure
(d) sea level pressure
(e) dewpoint temperature
d. sea level pressure
64
What is the term used to describe contours of temperature?
(a) isobars
(b) isotachs
(c) isotherms
(d) isodrosotherms
c. isotherms
65
What is the term used to describe contours of dewpoint temperature?
(a) isobars
(b) isotachs
(c) isotherms
(d) isodrosotherms
d. isodrosotherms
66
On a surface map, a strong temperature gradient exists in a location where ______ are packed closely together.
(a) isobars
(b) isotachs
(c) contours
(d) isotherms
(e) isodrosotherms
d. isotherms
67
What atmospheric variable does an altimeter measure?
(a) wind speed
(b) wind direction
(c) air temperature
(d) atmospheric pressure
(e) dewpoint temperature
d. atmospheric pressure
68
The slope of a pressure surface is greatest above which areas?
(a) high surface pressure
(b) low surface pressure
(c) large temperature gradients
(d) small temperature gradients
(e) None of the above is correct.
c. large temperature gradients
69
Which statement about upper air weather maps is not correct?
(a) Upper air weather maps are updated each hour.
(b) Upper air weather maps typically depict constant pressure surfaces.
(c) The data used to create upper air weather maps comes from rawinsondes.
(d) Upper air weather maps were first used extensively during World War II.
a. Upper air weather maps are updated each hour.
70
Isobars on constant height surfaces have their highest values in the same location where ________ contours have their highest values on constant pressure surfaces.
(a) wind
(b) width
(c) height
(d) curvature
(e) temperature
c. height
71
The approximate direction and speed of the wind at the 500 mb level can be determined from what type of map?
(a) A contour map showing the altitude (height) of the 500 mb surface.
(b) A map showing isotherms (lines of constant temperature) on the 500 mb surface.
(c) A map showing isodrosotherms (lines of constant dewpoint temperature) on the 500 mb surface.
(d) (a), (b) and (c) are all wrong. The only way to tell the direction and speed of the wind on the 500 mb surface is to have winds plotted directly on the chart.
a. A contour map showing the altitude (height) of the 500 mb surface
72
What map would you examine to locate the polar jetstream?
(a) surface map
(b) 900 mb
(c) 700 mb
(d) 500 mb
(e) 300 mb
e. 300 mb
73
At what altitude above sea level is the 850 mb pressure surface typically located?
(a) 1,000 ft
(b) 5,000 ft
(c) 10,000 ft
(d) 18,000 ft
(e) 30,000 ft
b. 5,000 ft
74
At what altitude above sea level is the 500 mb pressure surface typically located?
(a) 1,000 ft
(b) 5,000 ft
(c) 10,000 ft
(d) 18,000 ft
(e) 30,000 ft
d. 18,000 ft
75
At what altitude above sea level is the 300 mb pressure surface typically located?
(a) 5,000 ft
(b) 10,000 ft
(c) 18,000 ft
(d) 30,000 ft
d. 30,000 ft
76
A low-level jet is typically most distinct on which map?
(a) 850 mb map
(b) 500 mb map
(c) 300 mb map
(d) 250 mb map
a. 850 mb map
77
A front is typically most distinct on which map?
(a) 850 mb map
(b) 500 mb map
(c) 300 mb map
(d) 250 mb map
a. 850 mb
78
Which of the following can be identified with a 500 mb map displaying absolute vorticity?
(a) the low-level jet
(b) horizontal shear zones
(c) the location of a front
(d) waves in the flow pattern
(e) (b) and (d) can both be identified
e. B and D can both be identified
79
What type of weather product allows meteorologists to visualize the vertical structure of fronts, clouds, and jetstreams?
(a) upper air map
(b) cross section
(c) sea level pressure map
(d) all of the above
b. cross section
80
Which of the following would be seen most easily by examining a cross section?
(a) the horizontal precipitation pattern at the surface along a front
(b) the cloud cover across the United States east of the Mississippi River
(c) the location of troughs approaching the west coast of the United States
(d) the distribution and gradient of temperature in a severe storm from the cloud base to the tropopause
d. the distribution and gradient of temperature in a severe storm from the cloud base to the tropopause
81
Why is understanding stability important in the study of severe storms?
(a) Stability explains what causes tornadoes to form.
(b) Stability is the deciding factor to whether or not clouds form.
(c) Stability alone determines the location and intensity of convective storms in the atmosphere.
(d) Stability is not particularly important for severe storms. We can fully understand them without considering atmospheric stability.
c. Stability alone determines the location and intensity of convective storms in the atmosphere
82
Which best describes an air parcel?
(a) a cloud
(b) a large area of rain
(c) a volume of air that moves around in the atmosphere intact
(d) the bubble of air sometimes seen on the top of thunderstorms
c. a volume of air that moves around in the atmosphere intact
83
If an air parcel is displaced vertically in a stable environment, what will the parcel do?
(a) remain in its new position
(b) return to its original position
(c) turn east due to the pressure change
(d) turn north due to the pressure change
(e) accelerate away from its original position
b. return to its original position
84
What will happen if a parcel of air is displaced vertically in an unstable environment?
(a) It will remain in its new position.
(b) It will return to its original position.
(c) It will continue to accelerate away from its original position.
(d) None of the above. Air cannot be displaced vertically in the atmosphere.
c. It will continue to accelerate away from its original position
85
If a parcel of air is displaced vertically in a(n) ________ environment, it will _______.
(a) unstable; return to its original position
(b) unstable; remain in its new position
(c) stable; return to its original position
(d) stable; accelerate away from its original position
(e) neutral; accelerate away from its original position
c. stable; return to its original position
86
What is the term used to describes a process where a parcel of air does not mix with its environment?
(a) isobaric
(b) adiabatic
(c) anthropogenic
(d) compressional
b. adiabatic
87
As an air parcel rises what happens to its size and temperature?
(a) It expands and cools.
(b) It expands and warms.
(c) It contracts and cools.
(d) It contracts and warms.
(e) It oscillates in size but its temperature does not change.
a. It expands and cools
88
What is the reason for the difference between the values of the Dry Adiabatic Lapse Rate and the Moist Adiabatic Lapse Rate?
(a) These lapse rates occur at different altitudes resulting in different values.
(b) The two lapse rates are used under different stability conditions: stable versus unstable, resulting in different values.
(c) Latent heat released during condensation offsets some of the cooling of a rising air parcel, causing the moist adiabatic lapse rate to have a smaller value.
(d) Friction is only important when the air is moist and therefore causes the moist adiabatic lapse rate to be smaller.
(e) Moist air is less dense than dry air leading to a smaller value for the moist adiabatic lapse rate.
c. Latent heat released during condensation offsets some of the cooling of a rising air parcel, causing the moist adiabatic lapse rate to have a smaller value
89
If you wanted to evaluate the stability of the atmosphere, which weather product would you examine?
(a) sounding
(b) wind profiler data
(c) surface pressure map
(d) radar radial velocity image
a. sounding
90
What information on a sounding allows you to calculate the environmental lapse rate?
(a) pressure
(b) wind speed
(c) wind direction
(d) air temperature
(e) dewpoint temperature
d. air temperature
91
In the atmosphere, a parcel of air is ________ than its environment if the parcel is ______ the environment.
(a) more dense; warmer than
(b) more dense; the same temperature as
(c) less dense; colder than
(d) less dense; warmer than
(e) less dense; the same temperature as
d. less dense; warmer than
92
If an air parcel is ________, it will ____________ at the moist adiabatic lapse rate.
(a) saturated; expand and cool
(b) saturated; expand and warm
(c) saturated; contract and cool
(d) unsaturated; expand and cool
(e) unsaturated; contract and cool
a. saturated; expand and cool
93
Which of the following lapse rates is measured by a rawinsonde?
(a) Moist Adiabatic Lapse Rate
(b) Environmental Lapse Rate
(c) Dry Adiabatic Lapse Rate
(d) Aerological Lapse Rate
(e) Mental Lapse Rate
b. Environmental Lapse Rate
94
A conditionally unstable atmosphere is______ for an air parcel that is unsaturated and ______ for an air parcel that is saturated.
(a) unstable; stable
(b) unstable; unstable
(c) stable; unstable
(d) stable; stable
(e) neutral; unstable
c. stable; unstable
95
A saturated air parcel that is lifted will expand and cool at _______.
(a) an unpredictable lapse rate.
(b) the buoyant lapse rate.
(c) the dry adiabatic lapse rate.
(d) the moist adiabatic lapse rate.
(e) the environmental adiabatic lapse rate.
d. the moist adiabatic lapse rate
96
How can the atmosphere’s stability at a particular location be changed?
(a) change the dry adiabatic lapse rate
(b) change the moist adiabatic lapse rate
(c) change the vertical temperature structure
(d) change the vertical wind profile
c. change the vertical temperature structure
97
In terms of diurnal changes in stability, the atmosphere is typically most stable during _____ and least stable during _____.
(a) night; day
(b) day; night
(c) summer; winter
(d) winter; summer
a. night; day
98
What is the atmospheric stability in a thunderstorm environment?
(a) stable
(b) neutral
(c) unstable
(d) conditionally unstable
c. unstable
99
A lifted air parcel first becomes unstable when it reaches what point in the atmosphere?
(a) lifted index
(b) cloud base
(c) tropopause
(d) level of free convection
(e) lifting condensation level
d. level of free convection
100
The base of a thunderstorm cloud is found at the ________.
(a) lifting condensation level (LCL)
(b) level of free convection (LFC)
(c) level of rising parcels (LRP)
(d) dry adiabatic level (DAL)
a. lifting condensation level (LCL)
101
If air is lifted beyond its ________it will become unstable and rise on its own without any external forcing.
(a) dry adiabatic level
(b) moist adiabatic level
(c) level of free convection
(d) lifting condensation level
C. level of free convection
102
When an air parcel reaches the lifting condensation level it will ______ and when it reaches the level of free convection it will ________.
(a) change lapse rates from the dry adiabatic lapse rate to the moist adiabatic lapse rate; continue to cool at the moist adiabatic lapse rate
(b) become buoyant; form a cloud
(c) form a cloud; become buoyant
(d) both (a) and (b) are correct
(e) both (a) and (c) are correct
e. both a and c are correct
103
If an air parcel is lifted, it will first form clouds at the ________ and become buoyant (unstable) at the _________.
(a) level of free convection; tropopause
(b) lifting condensation level; tropopause
(c) level of free convection; lifting condensation level
(d) lifting condensation level; level of free convection
(e) lifting condensation level; level of explosive growth
d. lifting condensation level; level of free convection
104
SEE DIAGRAM: Which thick line is the temperature, right or left?
right
105
SEE DIAGRAM: At approximately what pressure is the level of free convection?
750mb
106
SEE DIAGRAM: If a parcel is lifted to the level of free convection, to what pressure level will buoyancy enable it to rise?
425mb
107
SEE DIAGRAM: At what pressure level is the lifting condensation level?
825mb
108
SEE DIAGRAM: At what pressure level is the cloud base?
825mb
109
SEE DIAGRAM: Estimate the value of the Lifted Index.
-7
110
Which of the following is not a force that controls the wind?
(a) Coriolis force
(b) frictional force
(c) electrostatic force
(d) gravitational force
(e) pressure gradient force
c. electrostatic force
111
Pressure varies in the vertical from 1013.25 mb at Earth’s surface (on average) to what value near the tropopause?
(a) ~300 mb
(b) ~30 mb
(c) ~3 mb
(d) ~0.3 mb
a. -300mb
112
What force counteracts the vertical pressure gradient?
(a) Coriolis force
(b) frictional force
(c) gravitational force
(d) horizontal pressure gradient
c. gravitational force
113
What type of weather system typically have the strongest horizontal pressure gradients found on earth?
(a) hurricanes
(b) ice storms
(c) tornadoes
(d) extratropical cyclones
c. tornadoes
114
Which statement about the pressure gradient force is true?
(a) It is directed from low to high pressure everywhere on earth.
(b) It is directed at a 90-degree angle to isobars.
(c) It is larger when the isobars are further apart.
(d) It is balanced by friction at high altitudes.
(e) All of the above are correct.
b. it is directed at a 90 degree angle to isobars
115
A strong pressure gradient near the surface is associated with which of the following?
(a) weak winds
(b) nearly calm winds
(c) strong and gusty winds
(d) higher concentration of ozone
(e) None of the above are correct.
c. strong and gusty winds
116
Where is the pressure gradient force directed from higher pressure toward lower pressure?
(a) only at the equator
(b) at all places on earth
(c) only in the Northern Hemisphere
(d) only in the Southern Hemisphere
(e) at all places on earth except for the equator
b. at all places on earth
117
The Coriolis force is:
(a) zero at the equator.
(b) due to the rotation of the earth
(c) stronger when the winds are faster, except at the equator.
(d) (b) and (c) only.
(e) (a), (b) and (c) are correct.
e. a,b, and c are correct
118
If the earth did not rotate, the Coriolis force would be:
(a) strongest at the poles and zero at the equator.
(b) strongest at the equator and zero at the poles.
(c) strong and negative everywhere on earth.
(d) zero everywhere on earth.
d. zero everywhere on earth
119
The __________ causes air to slow down near the surface.
(a) Coriolis force
(b) frictional force
(c) gravitational force
(d) vertical pressure gradient force
(e) horizontal pressure gradient force
b. frictional force
120
The __________ is directed toward the center of the earth.
(a) Coriolis force
(b) frictional force
(c) gravitational force
(d) vertical pressure gradient force
(e) horizontal pressure gradient force
c. gravitational force
121
How does Newton’s first law of motion relate to the atmosphere?
(a) air molecules moving in the atmosphere will continue to move at a constant speed in a straight line as long as no net force is exerted on the molecules
(b) an increase in internal energy of air molecules is equal to the amount of energy added by heating minus the energy lost as a result of work done by molecules
(c) the energy radiated by a cloud is directly proportional to the fourth power of the clouds temperature.
a. air molecules moving in the atmosphere will continue to move at a constant speed in a straight line as long as no net force is exerted on the molecules
122
Air cannot be in geostrophic balance in the boundary layer because of the .
(a) Coriolis force
(b) frictional force
(c) gravitational force
(d) vertical pressure gradient force
(e) horizontal pressure gradient force
b. frictional force
123
A geostrophic balance is achieved when the Coriolis force balances the
(a) Coriolis force
(b) frictional force
(c) gravitational force
(d) vertical pressure gradient force
(e) horizontal pressure gradient force
e. horizontal pressure gradient force
124
Which forces are in balance with respect to air motions within the boundary layer?
(a) vertical pressure gradient force and gravity
(b) horizontal pressure gradient force and frictional force
(c) horizontal pressure gradient force and Coriolis force
(d) horizontal pressure gradient force, Coriolis force, and frictional force
d. horizontal pressure gradient force, coriolis force, and frictional force
125
Air through a trough flows .
(a) clockwise
(b) cyclonically
(c) anticyclonically
b. cyclonically
126
If air is in geostrophic balance, it must flow ______ to isobars and be _______ the boundary layer.
(a) parallel; above
(b) parallel; within
(c) perpendicular; above
(d) perpendicular; within
a. parallel; above
127
What is the term used to describe a narrow band of strong winds encircling the Earth in middle-latitudes?
(a) cyclone
(b) jetstream
(c) jetstreak
(d) storm system
b. jetstream
128
Jetstreams in the upper troposphere are found above _______ in the lower troposphere.
(a) fronts
(b) heavy rain
(c) clear skies
(d) high-pressure systems
fronts
129
What is the term used to describe the net inflow of air molecules into a region of the atmosphere with the result of increasing the surface pressure?
(a) jetstreak
(b) divergence
(c) convergence
(d) diabatic process
c. convergence
130
Which statement about air motions is not correct?
(a) Air in low-pressure centers rises, leading to clouds and precipitation.
(b) Air in high-pressure centers sinks, leading to relatively clear skies.
(c) High-pressure centers are associated with divergence at the surface.
(d) Low-pressure centers are associated with strong convergence aloft.
d. low pressure centers are associated with strong convergence aloft
131
Gradient wind balance is achieved in the ________ when air flows parallel to _______ isobars.
(a) friction layer; curved
(b) friction layer; straight
(c) upper atmosphere; straight
(d) upper atmosphere; curved
d. upper atmosphere; curved
132
Air flowing around a low-pressure center (located above the friction layer) will move _______ its geostrophic value.
(a) faster than
(b) slower than
(c) the same speed as
(d) in the opposite direction compared to
b. slower than
133
What is the term used to describe air flowing at a speed slower than the geostrophic value?
(a) adiabatic
(b) anticyclonic
(c) subgeostrophic
(d) supergeostrophic
c. subgeostrophic
134
The effect of changing flow curvature in the jetstream is to create _________ downstream of the ridge axis and _________ downstream of the trough axis.
(a) divergence; divergence
(b) divergence; convergence
(c) convergence; divergence
(d) convergence; convergence
c. convergence; divergence
135
The divergent quadrants of a jetstreak are its _________ and ___________ quadrants.
(a) left entrance; left exit
(b) left entrance; right exit
(c) right entrance; left exit
(d) right entrance; right exit
(e) right entrance; left entrance
c. right entrance; left exit
136
What is the term used to describe a region of exceptionally strong winds found within the jetstream?
(a) jetstreak
(b) low-level jet
(c) polar jetstream
(d) minor jetstream
a. jetstreak
137
Strong divergence will result when the _________ of a jetstreak is co-located with the eastern branch of a _________.
(a) left exit; trough
(b) left exit; ridge
(c) left entrance; ridge
(d) left entrance; trough
a. left exit; trough
138
Low pressure will develop at the surface below the region of strongest _________.
(a) jetstreak
(b) curvature
(c) divergence
(d) convergence
c. divergence
139
Which statement is not correct?
(a) Friction always reduces the wind speed.
(b) Friction leads to the strengthening of surface low-pressure centers.
(c) Friction leads to a deflection to the left of the geostrophic wind direction, toward the low-pressure side of isobars.
(d) Friction always acts to turn the wind such that the flow has a component from higher pressure toward lower pressure.
(e) Friction influences air flow up to roughly 3 km above the surface.
b. Friction leads to the strengthening of surface low-pressure centers.
140
Convergence into an air column _________ mass to the column resulting in ________ surface pressure.
(a) adds; increased
(b) adds; decreased
(c) adds; no change
(d) subtracts; no change
a. adds; increased
141
Divergence aloft in the upper half of the troposphere is normally associated with which of the following?
(a) high-pressure development and divergence at the surface
(b) high-pressure development and convergence at the surface
(c) low-pressure development and divergence at the surface
(d) low-pressure development and convergence at the surface
(e) hot air during presidential elections
d. low-pressure development and convergence at the surface
142
34. If only atmospheric ______ were occurring in an air column, the pressure at the base of the air column would always ________.
(a) divergence; increase
(b) convergence; decrease
(c) divergence; decrease
(d) convergence; remain constant
(e) divergence; remain constant
c. divergence; decrease
143
If no divergence or convergence were occurring anywhere above the lower levels of the atmosphere, what would happen to any existing surface low-pressure systems?
(a) They would dissipate.
(b) They would intensify.
(c) They would maintain their intensity.
(d) They would develop into extratropical cyclones.
a. They would dissipate.
144
If an air column is heated more than the surrounding air, what will happen to the surface pressure at the base of the column?
(a) It will decrease.
(b) It will increase.
(c) It will remain the same.
a. it will decrease
145
If an air column is cooled through radiational cooling, what will happen to the surface pressure?
(a) It will increase.
(b) It will decrease.
(c) It will stay the same.
(d) It will become unbearable.
a. it will increase
146
Which of the following can enhance surface high-pressure systems?
(a) Convergence in the right exit region of a jetstreak
(b) Convergence due to curvature in the jetstream.
(c) The cooling of the air in the vicinity of the high.
(d) (a) and (b) are both correct.
(e) (a), (b), and (c) are all correct.
e. a,b, and c are all correct
147
Which of the following can enhance surface low-pressure systems?
(a) divergence in the left exit region of a jetstreak
(b) convergence due to curvature in the jetstream
(c) the cooling of the air in the vicinity of the low
(d) (a) and (b) are both correct.
(e) None of the above are correct.
d. a. and b are both correct
148
What type of surface pressure systems are typically associated with fair weather?
(a) high pressure
(b) low pressure
(c) both high and low pressure are associated with fair weather
a. high pressure
149
