exam 2 Flashcards
(145 cards)
1
Q
what are the three main temperature scales
A
fahrenheit, celsius, kelvin
2
Q
who developed the Fahrenheit scale and in what year
A
Gabriel Daniel Fahrenheit ; 1714
3
Q
based on mercury-in-glass thermometer based upon a “zero point” ; only in US
A
Fahrenheit Scale
4
Q
what are the three significant temperatures on the Fahrenheit scale
A
98.6 - human body temperature
212 - water’s boiling/steam point
32 - freezing/”zero” point
5
Q
who developed the Celsius scale and in what year
A
Anders Celsius ; 1742
6
Q
devised using the decimal scale and a “zero” point; used widely worldwide (except US)
A
Celsius Scale
7
Q
a degree of celsius is ________ (smaller/larger) than a degree of Fahrenheit by a factor of _____
A
larger ; 1.8
8
Q
what are the three significant temperatures on the Celsius scale
A
37 - human body temperature
100 - water’s boiling/steam point
0 - freezing point
9
Q
who developed the Kelvin scale and in what year
A
Lord Kelvin (William Thompson) ; 1848
10
Q
used in scientific formulas/applications ; no negatives on this scale ; the “zero” point is the cessation of molecular motion
A
Kelvin Scale
11
Q
what are the significant temperatures on the Kelvin scale
A
273 - freezing point of water
373 - water’s boiling/steam point
12
Q
temperature scale conversion: Fahrenheit to Celsius
A
(F - 32) / 1.8 = C
EX: 50 F = 10 C
(50 F - 32) / 1.8 = 18 / 1.8 = 10C
13
Q
temperature scale conversion: Celsius to Fahrenheit
A
C x 1.8 + 32 = F
EX: 30 C = 86 F
(30 C x 1.8) + 32 = 86 F
14
Q
units of measure ; developed in the early 20th century ; a method of evaluating energy demand and consumption
A
Heating/Cooling Degree Days
15
Q
what is the daily mean temperature that marks/determines when to be heating or cooling
A
65 F / 18.3 C
16
Q
if the average temperature is >65…
A
CDD
17
Q
if the average temperature is
A
HDD
18
Q
the degree difference between the average temperature and 65 F tells you…
A
the number of HDD or CDD
EX: high temp is 90 F , low temp is 60 F ; therefore the average temp is 75 F ; this is 10 F > 65 F ; therefore, it would be a 10 CDD observed for the day
19
Q
CDD season
A
Jan - Dec
20
Q
HDD season
A
July 1 - June 30
21
Q
what are the 2 factors of the heat stress index
A
temperature and humidity
22
Q
85% of body heat loss is from…
A
top of head to neck/shoulders
23
Q
what are the 2 main factors of the wind chill index
A
air temperature and wind speed
24
Q
what is the most important compound in the atmosphere
A
water vapor
25
the amount of water vapor (gas) in the atmosphere is _____ (higher/lower) in the polar regions and _____ (higher/lower) near the equator/tropical regions
lower (near 0%) ; higher (near 4%)
26
water vapor is very important when considering...
atmospheric stability
27
latent heat absorbed...
* *Cooling Process
- evaporation
- melting
- sublimation
>LAMES
28
latent heat released...
* *Warming Process
- freezing
- condensation
- deposition
>LRCDF
29
humidity
refers to any one of a number of different ways of specifying the amount of water vapor in the air
30
(AKA-water vapor density) ; the weight/mass of the water vapor per volume of air parcel
absolute humidity
31
comparing the weight/mass of the water vapor per volume of air parcel with the total weight/mass of the air in the parcel including the water vapor
specific humidity
32
comparing the weight/mass of the water vapor per volume of air parcel with the weight/mass of the remaining dry air
mixing ratio
33
ratio of the air's actual water vapor content compared with the amount of water vapor required for saturation at a given temp
relative humidity
34
relative humidity can be influenced, or changed, by...
- adding/subtracting moisture to air
| - changing given air temp
35
relative humidity has _______ relationship to temperature
inverse ; so if temperature is getting higher throughout the day, RH is getting low
36
the temperature to which a parcel of air would need to be cooled to (assuming no change in air pressure or moisture content) in order for the given parcel of air to reach saturation
dew point temperature
37
dew point temperature is always __________ air temperature
less than or equal to
38
when dew point temp = air temp...
air is saturated (relative humidity = 100%)
39
relative humidity is lowest when...
there is a greater difference between dew point temp and air temp
40
relative humidity is highest when...
there is a smaller difference between dew point temp and air temp
41
a lower dew point temperature means...
less moisture in air (cold air can hold less water)
42
a higher dew point temperature means...
more moisture in air
43
dew cell
directly measures the air's actual water vapor pressure (used in ASOS/AWOS sensor systems)
44
atmospheric stability refers to...
a state of equilibrium of the atmosphere
45
in order to determine atmospheric stability, we look at...
the temperature of a parcel of air as it rise and/or sinks in the atmosphere and compare that temperature to the temperature of surrounding air
46
when you force a parcel of air to rise...
it expands and cools
47
when you force a parcel of air to sink
it compresses and warms
48
when a given parcel of air expands/cools or compresses/warms with NO interchange of heat with its outside environment
adiabatic process
49
in unsaturated air, air cools/heats at a rate of...
5.5 F / 1000 Ft
50
in saturated air, air cools/heats at a rate of...
3.3 F / 1000 Ft
51
when the ELR is greater than the DALR, the atmosphere is said to be
absolutely unstable
52
when the ELR is greater than the MALR, but less than the DALR, the atmosphere is said to be
conditionally unstable
53
when the ELR is less than the MALR, the atmosphere is said to be
absolutely stable
54
stability is enhanced by...
1. radiational cooling of the earth's surface after sunset
2. cooling of air mass from below as it moves over a colder surface
3. subsidence of an air column
55
instability is enhanced by...
1. intense solar heating
2. heating of air mass from below as moves over a warmer surface
3. forceful lifting of air (orographic and frontal)
4. upward motion with surface air convergence
5. radiational cooling from nocturnal thunderstorm cloudtops
56
parcels rise in _____ (warmer/colder) air
warmer
57
ELR
Environmental Lapse Rate ; rate at which air cools with height
58
water that has condensed onto objects near the ground when the temperature of those objects has cooled below the dew point temperature of the surrounding air ; not a form of precipitation, but still an important source of moisture
dew
59
what happens when the air temperature falls below freezing after dew has formed?
frozen dew ; NOT CALLED FROST (frost is produced by deposition - meaning it does not pass through a liquid state)
60
a covering of ice crystals produced by deposition on exposed surfaces when the air temperature falls below the freezing point and the temperature of the exposed objects falls below the surrounding air's dew point temperature
frost
61
what kills more people annually than any other weather-related factors
heat
62
what are the four phases of the hydrologic cycle
evaporation, condensation, transpiration, infiltration
63
water going through the roots and out through the leaves of the plants
transpiration
64
soaking into the soil ; aquifer?
infiltration
65
if air temperature and dew point temperature are one degree apart, what is the RH
96%
66
there is a _______ (direct/indirect) relationship between dew point temp and moisture in air
direct ; more moisture in air at higher dew points, and less moisture in air at lower dew points
67
sling psychrometer : dry bulb records
actual air temperature
68
sling psychrometer : wet bulb records
NOT dew point temperature ; after wetting the shoestring and slinging it, the evaporative cooling yields a wet bulb temperature
69
through this we can determine RH & Dew Point Temp using dry and wet bulb temps and psychometric tables
sling psychrometer
70
electronic hygrometer
electrical conductors coated with moisture absorbing chemical (usually carbon); Passage of current varies as Relative Humidity varies; used in Radiosondes / Rawinsondes
71
infrared hygrometer
measures the amount of infrared energy absorbed by water vapor in a given sample of air; used in weather satellites (water vapor imagery)
72
hair hygrometer
based on a hair strand lengthening with higher RH; hair strands attached to an index dial
73
most clouds form as air _____, _______, & _______
rises, expands, and cools
74
a cloud with its base at the earth's surface
fog
75
most common type of fog we see in south central texas ; radiates heat away then cool to dew point temp ; fog forms because air becomes saturated ; little to no wind
radiation fog
76
most common type of fog along west coast ; horizontal wind/movement ; can occur with little wind ;
advection fog
77
latin root : stratus means...
"layer"
78
latin root : nimbus means...
"violent rain"
79
latin root : cumulus means...
"heap"
80
latin root : cirrus means...
"curl of hair"
81
if a parcel is colder than the air temp, what will happen
it will sink to get warmer/compress
82
if a parcel is warmer than the air temp, what will happen
it will rise to get colder/expand
83
when the parcel expands / cools or compresses / warms with interchange of heat with the outside environment
diabatic process ; but we assume adiabatic process
84
thermodynamic diagram : the yellow line is the...
parcel line
85
thermodynamic diagram : compare the yellow line to the...
air temperature line (NOT the dew point temp line)
86
thermodynamic diagram : when the parcel (yellow) line is left of the air temperature line, the atmosphere is...
stable
87
thermodynamic diagram : when the parcel (yellow) line is right of the air temperature line, the atmosphere is...
unstable
88
the quicker it gets colder with height the more ______ (stable/unstable) the parcel is
unstable
89
the slower it gets colder with height or if there are temperature inversions the more _____ (stable/unstable) the parcel is
stable
90
cloud formation process:
1. surface heating and free convection
2. topographic lift
3. widespread lifting (ascent) due to surface convergence
4. uplift along weather fronts (tornado capital causer)
91
Adding more moisture to the air than it can hold (you can see your breath when it is cold)
evaporation/mixing fog
92
Fog that forms when air is forced to move up slowly ; associated with topographic lift
upslope fog
93
cloud classification schemes : who made the first classification and in what year
Lamarck , 1802
94
cloud classification schemes : who made the second modification to the classification and in what year
Howard , 1803
95
cloud classification schemes : who made the last expansion to the classification and in what year
Abercromby & Hildebransson , 1887
96
cloud coverage is measure in what
octas
97
cloud coverage : 0/8
clear sky (CLR/SKC)
98
cloud coverage : 1/8 - 2/8
few clouds (FEW)
99
cloud coverage : 3/8 - 4/8
scattered (SCT)
100
cloud coverage : 5/8 - 7/8
broken (BKN)
101
cloud coverage : 8/8
overcast (OVC)
102
precipitation types
rain, freezing rain, drizzle, freezing drizzle, sleet, hail, snow
103
geostationary satellites
22,500 miles above ground ; images of same geographic area continuously
104
polar orbiting satellites
532 miles above ground ; closely parallel the earth's meridian lines ; they pass over the north and south polar regions with each pass
105
precipitation formation process : collision - coalescence process
warmer temperature process
106
precipitation formation process : bergeron process
colder temperature process
107
what is the water equivalent of snowfall
1" liquid rainfall = 10" snow
108
water equivalent of wet snowfall
1" liquid rainfall = 5" snow
109
water equivalent of dry powdery snow
1" liquid rainfall = 15" snow
110
what are the three types of precipitation measurement
standard rain gauge ; tipping bucket rain gauge ; weighing type rain gauge
111
what are things to remember when measuring snowfall
- avoid areas with drifting/blowing snow
- away from trees/buildings
- measure in 3 places with a ruler and average
112
CLOUD ID: wispy streamers ; lower/shallower near poles ; "mares tales" ; fair weather
cirrus
113
precipitation that does not reach the ground
virga
114
what are the high clouds
cirrus, cirrocumulus, cirrostratus (all at or above 20,000 feet)
115
CLOUD ID: occasional precipitation that doesn't hit the ground (virga); always white ; scales of fish ; small puffs
cirrocumulus
116
CLOUD ID: "halo" -usually transparent to sunlight; shadows are cast ; thin sheet like layer
cirrostratus
117
what are the middle clouds
altocumulus ; altostratus (6,500 - 20,000 ft)
118
CLOUD ID: gray base-distinguishable ; "rising castles" ; common on mornings of severe weather days ;
altocumulus
119
CLOUD ID: gray-blue/gray (NEVER white) ; no shadows cast ;
altostratus
120
what are the low clouds
stratus ; stratocumulus ; nimbostratus
121
CLOUD ID: uniform grey stratified layer ; light drizzle or light snow possible ; very uniform cloud bases
stratus
122
CLOUD ID: lumpy cloud layer ; blue sky visible between cloud elelments
stratocumulus
123
CLOUD ID: dark grey wet-looking cloud ; light to moderate rain (never heavy precipitation) ; bases are normally impossible to identify ; no sun or moon visible through cloud mass
nimbostratus
124
what are the clouds of vertical extent
cumulus ; cumulonimbus
125
CLOUD ID: only out when the sun is ; when they have a flat base, air has reached dew point temp ; dense and well defined ; cotton puffs
cumulus
126
more cloud towering means...
more instability
127
CLOUD ID: large, towering, precipitating ; thunder, lightning and rain ; severe storms
cumulonimbus
128
CLOUD SUBTYPES: lenticularis
lens like
129
CLOUD SUBTYPES: fractus
broken or fractured
130
CLOUD SUBTYPES: humilis
of small size
131
CLOUD SUBTYPES: congestus
to pile up/become congested
132
CLOUD SUBTYPES: undulatus
having waves
133
CLOUD SUBTYPES: translucidus
to shine through
134
CLOUD SUBTYPES: mammatus
bag/pouch like ; mammary (extreme turbulence)
135
CLOUD SUBTYPES: pileus
cap
136
CLOUD SUBTYPES: castellanus
small castles
137
CLOUD SUBTYPES: contrails
condensation trails (behind jets)
138
FORMS OF PRECIPITATION: falls from low stratus clouds ; drops are less than 0.02" ; trace amounts of rainfall
drizzle
139
FORMS OF PRECIPITATION: diameters greater than 0.02"; generally produced by nimbostratus or cumulonimbus clouds; ***intensity is based upon rate of fall
rain
140
what does trace mean
not measurable, but occurs
141
FORMS OF PRECIPITATION: rain that falls in liquid form but freezes upon impact; droplet size greater than 0.02"; ice storms
freezing rain
142
FORMS OF PRECIPITATION: drizzle that falls in liquid form but freezes upon impact; droplet size less than 0.02"; difficult to see-dangerous
freezing drizzle
143
FORMS OF PRECIPITATION: frozen raindrops (freeze in air, not upon impact) ; diameter is 0.2" or less; distinctive sound when hitting ground
ice pellets (sleet)
144
FORMS OF PRECIPITATION: produced through deposition ; up to 0.8" in diameter ; intensity is always based upon visibility
snow
145
FORMS OF PRECIPITATION: always produced by cumulonimbus clouds ; large liquid water contents, large cloud droplet size, and great vertical height are favorable in creating this form of precipitation ; diameter of 1" (size of quarter) or greater is one criteria that classifies a thunderstorm as being "severe"
hail
