G1250 - Exam 2 Flashcards
notes from slides and questions from exam
1
Q
what is the definition of vapor pressure (e)
A
(e) is the amount of pressure in mb exerted by water vapor in the air
2
Q
vapor pressure (e) is the measure of the
A
actual vapor content of the air
3
Q
when evaporation rate is equal to the condensation rate it means that
A
vapor pressure is at equilibrium (saturated)
4
Q
what is the definition of saturation vapor pressure (es)
A
es is the vapor pressure of the air when the air is saturated
5
Q
es is the measure of the
A
maximum vapor content of the air
6
Q
es is the pressure exerted by the
A
maximum amount of vapor that can be in the air at a given temperature
7
Q
what is saturation
A
e=es
7
Q
what is subsaturation
A
e<es
8
Q
what is supersaturation
A
e>es
9
Q
what is the definition of relative humidity
A
the actual vapor pressure of the air (e) relative to (/) the vapor pressure exerted by the air if it were saturated (es)
10
Q
what is the formula for RH
A
RH=e/es *100%
11
Q
vapor pressure is a measure of the
A
actual rate content of the air
12
Q
saturation vapor pressure is a measure of the
A
maximum vapor content of the air at a given temperature
13
Q
when air temperature increases the
A
saturation vapor pressure increases
14
Q
when air temperature increases the saturation vapor pressure
A
increases exponentially
15
Q
what is the formula for dew point depression
A
DPD= t-td
16
Q
DPD is the approximate measure of
A
RH
17
Q
aerosols are made of
A
dust, smoke, and pollen
18
Q
what is the range of aersols
A
0.2-10um
19
Q
as aerosols concentration decreases as size
A
increases
20
Q
what is a hygroscopic aerosols
A
when condensation when RH<100%
21
Q
what is hydrophobic aerosols
A
when there is no condensation when RH>100%
22
Q
condensation wil not occur if nuclei are
A
not present
23
Q
what happens when condensation occurs in the atmosphere when the earths surface cools overlying air
A
it creates fog
24
what happens when condensation occurs in the atmosphere when rising air causes expansional cooling
it creates clouds
25
what are the three types of fog
radiation fog
advection fog
steam fog
26
how does radiation fog form
forms during clear calm nights
earths surface cools the overlying air to Td
additional cooling causes condesnation to occur
27
how does advection fog form
forms both during the day and night
air with Td greater than surface T advected by wind over surface
often occurs during snow melt
28
how does steam fog form
forms over warm bodied of water
cold air advanced by the wind over the water
water warms the overlying air
water evaporates into the air
warm moist air rises via convection
29
when water vapor condenses to form a cloud droplet
it does so on a condensation nucleus
30
fog forms when
saturated air is cooled at the earths surface
31
why do clouds forms
clouds forms when saturated air is cooled
32
warm clouds are how warm/cold?
T>32 degrees f
33
warm clouds are
all liquid and no ice
34
warm clouds:
collision and coalescence
larger droplets collide and merge/coalesce with smaller droplets
efficiency increases as droplet size increases
35
cold clouds form when temperateures are
T<32 degrees f
36
ice clouds are ice crystals which are
supercooled droplets and vapor
37
cold clouds are Deposition nuclei wich are
hexagonal and rare
38
cold clouds composed almost entirely of
supercooled droplets
39
step 1 of the Bergeron Process
vapor deposits on crystal
ice crystals grown and e decreases
40
step 2 of Bergeron Process
crystal growth decreases
droplets evaporate and e increases
41
step 3 & 4 of Bergeron Process
vapor deposits on crystals
crystal growth increases and e decreases
42
step 5 of the Bergeron Process
RHi = 100%
deposition = sublimation
crystal growth stops
43
what is the definition of the Bergeron Process
the process by which ice crystals grow at the expense of supercooled droplets in a cold cloud
44
a cold cloud is comprised almost entirely of supercooled water droplets because
deposition nuclei are hexagonal and rare
45
within a cold cloud there exists a single ? and ?
temperature and vapor pressure
46
in a cold cloud, more vapor is required to saturate the air around an
supercooled water droplet
47
the Bergeron process occurs n a cold cloud because the air around ice crystals is ? and the air around supercooled water droplets is either
supersaturated, saturated or subsaturated
48
the Bergeron process will continue in a cold cloud until all of the ?
supercooled droplets have evaporated
49
precipitation falls as snow when
air temps remain below freezing throughout the atmosphere
50
partly frozen drops refreeze and become sleet when
it starts as snow, falls through a shallow warm layer, and then falls through a deep cold layer
51
when rain drops become "supercooled" in cold air and freeze on contact causing
Freezing rain
52
a cold cloud is comprised almost entirely of supercooled water droplets because ?
deposition of nuclei are hexagonal and rare
53
within a cold cloud there exists a single ? and ?
temp and vapor pressure
54
in a cold cloud, more vapor is required to saturate the air around a(n)
supercooled water droplet
55
the Bergeron process occurs in a cold cloud because the air around ice crystals is ? and the air around supercooled water droplets is either ?
supersaturated, saturated or subsaturated
56
the Bergeron process will continue in a cold cloud until all of the ?
supercooled droplets have evaporated
57
surface highs flow
cw and out
58
surface lows flow
ccw and in
59
what are the forces that cause surface wind (V)
pressure gradient force
Coriolis force
friction
60
what are the forces and wind represented by vectors
arrow has both direction and magnitude
vectors have both left and right hand sides
61
what goes into the pressure gradient force
- only force that can act on air at rest
- directed from high to low pressure
- points in direction of rate of greatest pressure decrease
- perpendicular to the isobars
- magnitude increase as the pressure gradient increases
- PGF increases as distance between isobars decrease
62
the coriolis force is a ? force
apparent
63
what does it mean to be an apparent force
its a deflection of a large-scale motions
64
what causes the Coriolis Forces
latitudinal dependence of either radial velocity
65
what factors go into the Coriolis Force
- always acts 90degrees to the right of the wind in northern hemisphere
- increases with wind speeds (=0 when the wind is calm)
- f=0 at the equator and increases with latitude
66
PGF indicates
the wind (v)
67
f acts
90 degrees to the right of V
68
V accelerated and turns to the
right to strike a balance between PGF and f
69
acceleration and turning continue until
balance is achieved
70
Geostrophic wind defined as
wind that results from a balance between PGF and f
71
geostrophic winds are
- always parallel to isobars
- low pressure to the left
- high pressure to the right
- explains 80-85% real wind
72
friction causes what
- Vg decreases
- f decreases
- PGF becomes dominate force
- V turns toward PGF
- low pressure left side of wind
73
what is the relationship between upper level and surface circulations
surface highs and low locations determined by upper level circulation pattern
74
what is the definition of constant altitude
column pressure is greater over warm air than cold air
75
what is the definition of constant pressure
warm column height is greater then cold column height
76
isoheights are what color on a 500mb map
solid blue
77
isotherms are what color on a 500mb map
dashed red
78
according to the meteorological application wind speeds
increase with increasing height
79
PGF directed from high to low heights ? greatest height decrease
towards
80
PGF is perpendicular to the
isoheight lines
81
PGF magnitude increases as
distance between isoheights decrease
82
upper level winds have a ? component
westerly
83
temps from the equator to the pole
decrease
84
what is the definition of upper level ridges
axis of high heights and warm column temperatures
85
what is the definition of upper level troughs
axes of low heights and cold column temperatures
86
meridional wave patterns are for what type of amplitude waves
high amplitude waves
87
meridional waves are
? in the south in troughs
? in the north in ridges
cold in the south
warm in the north
88
zonal wave patterns are ? amplitude waves
low amplitude waves
89
zonal waves are
? air north
? air south
cold air north
warm air south
90
schematic of 3-D of ridges and troughs are defined as
heights slope down toward the north as column becomes progressively colder
91
cw circulation around
highs/ridges
92
ccw circulation around
lows/troughs
93
if the isoheights are curved, centripetal force vectors points towards
the center
94
Ridges Ce act in
the same direction as the Coriolis force
- f becomes large relative to the PGF
(SUP)
95
troughs Ce act in
the same direction as the PGF
(SUB)
96
Gradient wind results from
a balance between PGF, f and centripetal force
97
geostrophic in areas of
straight flow between ridges and troughs
98
as cars approach a traffic jam, the distance between them decreases
cars converge
99
as cars exit a traffic jam, the distance between them increases
cars diverge
100
vapor pressure is defined to be a measure of the
actual vapor content of the air
101
saturation vapor pressure is defined to be a measure of the
maximum vapor content of the air at a given temperature
102
a cloud forms when ?
rising saturated air cools as a result of expansion
103
collision and coalescence occurs on a warm cloud when ?
large droplets overtake smaller droplets and merge
104
the pressure gradient force
is directed from high to low pressure
points in direction of rate of greatest pressure decrease
is perpendicular to the isobars
105
the coriolis force
acts 90 degrees to the right of the motion in the northern hemisphere
106
the geostrophic wind
results from a balance between the PGF and f
always blows parallel to the isobars
has low pressure on its left
107
water is a unique substance in nature because it is ?
the only one that can exist in all 3 phases at the same time
108
the freezing and melting points of water are ? and ?, respectively
-40,32
109
evaporation is a cooling process because ?
water absorbs energy from the environment when it evaporates
110
condensation is warming process because ?
water releases energy to the environment when it condenses
111
latent heat ?
is the energy required to change the phase of water at a constant water temperature
112
latent heat differs from heat in that only latent heat ?
is used to change the phase of an object rather than its temperature
113
vapor pressure is a measure of the ?
actual vapor content of the air
114
saturation vapor pressure is a measure of the ?
maximum vapor content of the air at a given air temperature
115
the dew point temperature is defined to be the temperature ?
to which the air must be cooled to become saturated
116
air is subsaturated when the vapor pressure is ?
less than the saturation vapor pressure
117
air is supersaturated when the vapor pressure is ?
greater than the saturation vapor pressure
118
for a given temperature, the relative humidity of air is defined to be the ?
vapor pressure of the air relative to the saturation vapor pressure of the air at that temperature
119
radiation fog forms when ?
the ground cool the air above it to saturation on clear, calm evenings
120
advection fog forms when ?
warm, humid air flows over a much over colder surface, which cools the air to saturation
121
steam fog forms when ?
cold air flows over much warmer water which leads to evaporation and rising air, which cools to saturation
122
clouds form when
rising air cools via expansion to its dewpoint
123
collision and coalescence occur in a warm cloud because
droplets with different sizes fall at different speeds
124
cold clouds initially consist primarily of supercooled droplets and just a few ice crystals because ?
deposition nuclei are hexagonal and rate in the atmosphere
125
the vapor pressure inside of a cold cloud is
always the same around both ice crystals and supercooled droplets
126
the saturation vapor pressure in a cold cloud
greater around a supercooled droplet than around an ice crystal
127
given a cold cloud with a single temp, and vapor pressure the relative humidity is ?
greater around an ice crystal than around a supercooled droplet
128
the bergeron process explains why ? in a cold cloud
ice crystals grow at the expenses of supercooled droplets
129
the bergeron process takes place in a cold cloud because ?
the air around ice crystals is always supersaturated
130
given that snow falls from the cloud, the vertical temp profile shown below will cause ? to be observed a the earths surface
sleet
131
vertical temperature profile shown below will cause ? to be observed at the earths surface
freezing rain
132
the pressure gradient force is an ? force, and its vector is directed across Isobars at the surface from ? pressure
real, high to low
133
the coriolis force is an ? force and its vector is always directed 90 degrees to the right of the ? vector
apparent, wind
134
the geostrophic wind is a wind results from a balance between the ? an ? forces
pressure gradient, coriolis
135
friction causes
the wind to cross isobars at an angle from high to low pressure
wind to slow
coriolis force to decrease
136
