Midterm Flashcards
(127 cards)
1
Q
What is geography?
A
uses spatial (location based) information to study of the structure and behavior of the physical and human world
2
Q
How geographers practice scientific method:
A
Form location based hypothesis
use location based methods to test hypothesis
Find results that support or challenge hypothesis
3
Q
Geographic answer to this question: Why have people historically lived in populations with similar skin tones?
A
Locations promote the survival of particular skin tones (darker tones in sunnier regions)
4
Q
Answer in geographic way of thinking : why do the gulf states experience massive summer rains?
A
Region is next to tropical warm water, promoting hurricane development, due to earths rotation, hurricanes travel west toward gulf
5
Q
Geography is a _____ and a way of _______.
A
tool, way of thinking
6
Q
geography is inherently __________
A
multidisciplinary
7
Q
Geography makes use of spatial info, most efficiently represented with _______
A
maps
8
Q
What is the difference between weather and climate?
(Temporal/spatial scale)
A
Weather = hours to weeks
Climate = decade or longer
Weather = city to county
Climate = larger regions
Weather influences what people wear
Climate influences long term activity (given policies, infrastructure)
9
Q
Basic unit of time scale (how long a system lasts) and spatial scale (how large a system is)
A
second
meter
10
Q
Time and spatial scale of dust devils and gusts
A
Microscale
seconds to minutes
< 1km
11
Q
Time and spatial scale of thunderstorms, land sea breeze
A
Mesoscale
minutes to hours
1-100km
12
Q
Time and spatial scale of westerlies and hurricanes
A
Macroscale
Planetary
Synoptic
Weeks or more (westerlies)
Days to weeks (hurricanes)
1000 - 40,000 km
100 - 500 km
13
Q
This course focuses on what scale?
A
Micro-scale
14
Q
What is the atmosphere? What are the layers of the atmosphere?
A
All the air around the planet
Thermosphere
Mesosphere
Stratosphere
Troposphere
15
Q
Characteristics of thermosphere
A
mix of very little air and a lot of space, but each air molecule absorbs a large amount of energy
16
Q
Characteristics of mesosphere
A
generally in the middle of the atmosphere and is where extraterrestrial objects are destroyed before hitting earth’s surface
17
Q
Characteristics of stratosphere
A
contains the ozone layer, which protects the earth’s surface from harmful sun rays (i.e. UV radiation)
18
Q
Characteristics of the troposphere
A
generally the lowest 10 km of the atmosphere and is in direct contact with the earth’s surface. Virtually all human activity occurs here. Thus, tropospheric activity impacts humans and surface conditions (and vice versa).
19
Q
What is the lower part of the troposphere called? How thick is it?
A
Planetary Boundary Layer (PBL)
fluctuates between .1km and 2km
directly influenced by the surface roughness and heating of the earth
surface friction, terrain and solar heating all influence, causing turbulence, convective activity and changing wind direction
20
Q
Subregions of the troposphere
A
PBL
Turbulent surface layer
Roughness Layer
Laminar Boundary Layer
21
Q
characteristics of the planetary boundary layer
A
well-mixed through turbulence caused by friction and convection. Depth varies diurnally – thicker during the day and thinner at night
22
Q
characteristics of the turbulent surface layer
A
intense small-scale turbulence due to surface convection and roughness. It is thicker during the day (50m) and thinner at night. Time scale on the order of seconds.
23
Q
characteristics of the roughness layer
A
thickness depends on height of roughness element (i.e. Buildings and trees). It can be 1-3 times the height of the roughness element.
24
Q
characteristics of the laminar boundary layer
A
thickness depends on wind speed. Thicker layer with lower wind speed.
25
Characteristics of a system
assemblage of parts into a clearly
spatially and temporally defined
cannot be unlimited
cannot be random
open or closed to energy or mass
balance between inputs and outputs
input --> process --> response
26
What is the EAS? What are its two main levels?
EAS stands for earth atmospheric system. It is an open energetic system and closed material system made of two levels - the earth (surface) and the atmosphere
27
EAS is in a state of _______________
dynamic equilibrium- different aspects of the system are changing to maintain balance. The EAS works to maintain this balance across spatial and temporal domains
28
_______ is an organizing principle in nature.It is the reason for all weather events and climate processes
energy
29
Energy is ________
Work is ________
Force is ______
Acceleration is ______
(only applies to mechanical energy)
the ability or capacity to do work
force applied over distance, or movement of matter over distance
(Newton meter, Nm)
is mass multiplied by acceleration (Newton, N)
the rate of change of speed (meters per second per second; m/s2)
30
mechanical energy is converted to _______
calories
One calorie = 4.186 Joules (J) and, a Joule is a Newton Meter (Nm).
31
2 Types of energy
Kinetic energy– associated with motion
Gravitational Potential Energy– associated with the height of an object above a
surface
32
energy can be used as
Sensible Heat– internal energy which may be sensed or measured (i.e., with a
thermometer).
Latent Heat- energy used to change the state of water.
33
When energy is used to change the state of water, it is called _______
When this happens, that energy is not used to change the temperature of water.
latent heat (LH).
34
When water changes from ice to liquid or from liquid to vapor, it ______ LH.
When water changes from vapor to liquid or from liquid to ice, it ______ LH.
absorbs
releases
35
Latent heat of __________ is absorbed or released when water converts between
vapor and liquid.
vaporization
36
Latent heat of _______ is absorbed or released when water converts between liquid
and ice.
fusion
37
Latent heat of _________ is absorbed when water changes from ice to vapor
sublimation
38
Latent heat of ________ is released when water changes from vapor to ice.
deposition
39
All objects ________ energy (except black holes).
radiate
40
All objects gain their energy from ________ (except stars).
outside sources
41
All radiation is measured in _________.
wavelengths
(A basic unit of wavelength is called a micrometer or micron = 10-6 m).
42
All objects radiate across a __________.
spectrum of wavelengths
43
Visible light falls between ______ and _____
.4 to .7 microns
44
Radiant energy is measured in
Joules (J)
45
Definition of Radiant Flux
Radiant flux is the flow of radiation over time (Joules per second: J/s).
J/s is also called a Watt (W).
46
Definition of radiant flux density
Radiant flux density is the flow of radiation over time and space (Joules per
second per square meter: J/s/m2 aka W/m2).
47
Emittance is _________.
Irradiance is _________.
the radiant flux density emitted by a surface
the radiant flux density incident upon a surface
48
A blackbody is
an object that emits radiation at the maximum possible intensity
for every wavelength. It has a perfectly efficient release of all its energy. The sun is
a blackbody.
49
A graybody is
an object that emits radiation at less than the maximum possible
intensity. Some of the energy is retained. It has a less than perfectly efficient
release of energy. The earth is a graybody.
50
Emissivity is
the ratio between the actual emittance of a surface vs the ideal
emittance of a black body, at the same wavelength and temperature. It is basically
how efficient an object releases energy. The unreleased radiation is available for
use as heat energy.
51
Absorptivity is
the ratio between the amount of radiant energy absorbed by a
surface vs the total amount of energy incident upon that surface. It is basically how
efficient an object absorbs energy.
52
Stefan-Boltzmann’s Law says there is a relationship between
the temperature of
an object and the amount of energy emitted from that object. It describes the total energy radiated by an object at a
given temperature.
53
Wien’s Law says there is a relationship between
the temperature of an object and
the wavelength of maximum emission. It describes the wavelength at which an object emits its maximum
amount of energy. A warmer object generally emits energy at a smaller
wavelength.
54
Equation for Stefan Boltzmann's Law
E = ε σ T4
* E = energy flux density (W/m2).
* ε = emissivity, ranges from 0-1.
* σ = 5.67 x 10-8 (W/m2).
* T = Temperature in Kelvin.
55
Equation for Wien's Law
λmax = 2880 / T
* λmax = wavelength (in microns) at which the maximum amount of energy is
emitted.
* T = Temperature in Kelvin.
56
The amount of solar radiation (W/m2) that falls on a surface is
Irradiance
57
The quantity and quality of solar energy incident upon earth’s surface depends on:
1. Solar emissivity.
2. Angle of incidence.
3. Atmospheric transparency.
4. Attenuation.
58
Solar emissivity (aka _________, Σ) is described
by ___________ (Σ = εσT4) and ______(λmax = 2.88x103 / T)
the radiant flux density emitted by the sun
Stefan-Boltzmann
Wien's Law
59
The surface of the sun averages a temperature of approximately ________. Thus,
from Stefan-Boltzmann’s Law, its solar flux density is ____________.
.
10,000C
6.32x108 W/m2
60
Once that energy reaches the top of Earth’s atmosphere (aka TOA) it is known as the _________. It is diminished down to an average of _________.
Solar Constant
1,370 W/m2
61
Angle of incidence is an astronomical factor that affects the intensity of solar
energy flux. It depends on _________ and ________.
the time of year
time of day
62
Higher angles result in _____ intense solar radiation, lower angles result in _____
intense solar radiation.
more
less
63
During nighttime, angle of incidence is __________ because the sun is below the
horizon. Thus, irradiance is ____.
negative
0
64
What determines the amount and type of solar energy that is transferred from the TOA to the earths surface?
Atmospheric transparency
65
the proportion of energy that can flow straight through a surface
transmissivity
66
What are the three things that happen to energy when it hits the atmosphere?
Transmitted (goes through)
Absorbed
reflected
67
What is scatter?
when gas molecules intercept and "knock out" parts of the electromagnetic spectrum
68
What are examples of gases that absorb energy much more effectively than normal air (N2 and O2) ?
Carbon Dioxide (CO2), water vapor (H20), methane (CH4), nitrous oxide
(NOx), and ozone (O3)
69
what are atmospheric windows?
wavelengths of high transmissivity, wavelengths at which the earth and sun emit their max energy
70
What is the reduction in solar radiation intensity as light travels through the atmosphere. What does this influence?
Attenuation
influences the type of solar energy that reaches the earths surface and the way we visualize it
71
name for the distance that solar radiation must travel to get through the atmosphere
path length
72
a longer path means _______ attenuation of a solar beam
more
73
the path length of solar radiation through the atmosphere varies with ______ and ______. It is _________ near sunrise and sunset and the _______ near noon and _________ in winter and _________ in summer,
time of day
time of year
longest shortest
longest shortest
74
True or false: all wavelengths are scattered at the same rate
false
75
What is the Angle of refraction?
the angle at which light bends as it transfers between mediums
76
when light first reaches EAS (TOA) it is ______
white
77
when light travels through the earth's atmosphere, it experiences _______ scattering in which atmospheric gases scatter ________ wavelengths of light (blue light) and the most and longer wavelengths of light (yellow red) the least
Rayleigh scattering
78
what is diffuse radiation?
How do w perceive different colored light as a result?
the term refers to the indirect path of light after scattering
yellow red light arrive at the earths surface directly from the sun. Blu light arrives a the surface from all directions
79
why do mornings and evenings have redder skies
path of light is longer at sunrise and sunset and therefore all th blu light gets scattered out
80
what is mie scattering?
What is turbidity?
occurs evenly across all wavelengths because the light is scattered by large particles from a turbid atmosphere
Turbidity is any condition of the atmosphere that reduces its transparency to
radiation (i.e. clouds, dust, aerosols, pollen, haze, etc.).
Mie scattering causes clouds to look white because all wavelengths are scattered, and the different colors still combine to make white light.
81
where do energy exchanges and climatic responses occur?
At the surface (plane with no depth), over a volume
82
what is an active surface?
chief site of the exchanges of energy and
mass in a system
essentially no depth, no mass, no energy
Active surface is complex, situation changes with each type of surface, water vegetation, sand etc
83
what is radiation?
energy that emits from surfaces, flows between mediums through radiative transfer
84
SH transfers through convection and conduction while LH only transfers through
convection
85
what is convection?
is the vertical movement of liquid that is driven by internal energy
heating and expanding the liquid from within. It is the most effective form of
transfer and mixing in the atmosphere
86
what is conduction?
Conduction is the transfer of SH between mediums through direct contact. It occurs via the collision of molecules.
87
What is the difference between radiative energy and heat energy?
when we talk about radiative energy we are usually referring to shortwave or long wave radiation. When we talk about heat energy, we are usually referring to sensible and latent heat
88
At the atmospheric level, sunlight _____ _____ and ______
reflects, absorbs and transmits
89
At the earth level, sunlight ______ and ______
reflects and absorbs
90
sources of longwave radiation in the EAS
atmosphere and earth
91
At the ‘atmosphere level’, absorbed
________ energy is emitted upward and
downward
long wave
92
At the earth level, absorbed energy is emitted upward as __________
longwave radiation
93
No change in a volume’s energy storage occurs when ____________________, or when_______________________.
the volume is in balance over a
long period of time
a surface (with no depth) is the site of the exchanges
94
when input of energy into a volume is greater than output _______ happens, causing warming
convergence
95
when input of energy into a volume is less than output _______ happens, causing cooling
divergence
96
Positive net change in energy storage leads to ___________
warming
97
True or false: the type of net change in energy storage may occur with any form of energy –
radiation, convection, conduction
True
98
when convergence in a volume of water persists over a long period of time, ________ occurs
evaporation or melting
99
when divergence in a volume of water persists over a long period of time, ________ occurs
condensation or freezing
100
What is the latent heat of melt/freeze
the energy used to change water between its solid and
liquid states.
334 Joules of LH is required to freeze/melt one gram of water.
101
What is the eLatent heat of vaporization/condensation
The energy used to change water
between its liquid and gaseous states.
2230 Joules of LH is required to
evaporate/condense one gram of water.
102
ice to gas=
gas to ice =
sublimation
desublimation
103
on average the earth receives ________ of energy from the sun (aka the solar constant)
1,367 W/m^2
104
Three distinct layers within the PBL
Convective Boundary Layer
Laminar Layer
Subsurface Layer
105
Energy flow at each layer within the PBL depends on
Δz The distance the energy travels (i.e., Point A to Point B).
C Heat capacity of the medium.ΔT Temperature difference between the two locations.
Δt The amount of time that passes.
106
Th average change in temp depends on
the amount of energy
absorbed and the thermal properties of the absorbing volume (i.e., soil, air, water)
107
Two thermal properties that influence energy absorption
Specific Heat – a property of mass (kg) – the amount of energy it takes to
raise/lower the temperature of one unit mass (kg) of a substance by 1 Kelvin.
Heat capacity – a property of volume (m3) – the amount of energy it takes to
raise/lower the temperature of one unit volume (m3) of a substance by 1 Kelvin.
108
Apply heat capacity to a pot
metal has low heat capacity so we want it as the base to heat up the water fast
wood has high specific heat capacity so we want it as the handle in order not to burn anyone
109
Thermal properties of water that make it heat up and cool down slower than sand
sun penetrates water and therefore heat is less condensed
heat capacity of water is greater and therefore takes more energy to heat up
water mixes so heat is dispersed
water evaporates, letting heat out
110
types of movement associated with three sublayers of the PBL
Convective Boundary Layer (turbulent flow)
Laminar Layer (laminar flow)
Subsurface Layer (laminar flow)
111
thermal diffusivity
The ability to transfer energy
- It is the rate of heat transfer within a material.
112
What type of energy transfer occurs in the convective boundary layer?
free convection
often well mixed so there aren't big differences in temp throughout
turbulent surface layer and roughness layer follow same dynamics and are mixed
113
what is the smallest energy transfer layer of the PBL? How thin is it?
Laminar layer
millimeters thin
114
laminar layer adheres to all surfaces ta which motion is laminar. What does this mean? Other characteristics?
streamlines are parallel to the surface
not mixed
exists in slower movement
becomes thinner as wind speed increases
very large thermal gradient due to the lack. of mixing, insulating surface from atmosphere
115
how dos energy travel through thee laminar layer?
radiation and conduction, highlights importance of molecular diffusion
116
What kind of energy exchanges are there in the subsurface layer (aka the 1-meter-thick soil or ground layer)
mostly molecular (aka not turbulent) with energy flowing from areas
of high concentration to areas of low concentration
117
The rate of energy transfer between two locations within this layer depends on the
________________________ between the two locations and the ___________________ since
most of the transfer occurs by molecular collisions transferring kinetic energy.
temperature difference
thermal diffusivity
118
Where are the greatest thermal responses found and why?
at the surface, because that is where energy exchanges are most prominent, diminish the further they are from the surface
119
Lapse (temp decrease with height) happens in the _______
Inversion (temp increase with height) happens during the ______
day
night
120
A surfaces ability to accept for release heat is called
It is expressed as _______
thermal admittance
Expressed as thee temperature change produced bu a given heat flux, more so property of the surface than a volume
121
What is thermal conductivity?
The amount of heat transferred through a medium
- depends on soil depth, moisture, porosity, conductivity of individual particles
122
the speed at which temp moves through the soil and thee depth of the thermal influence
proportional to thermal conductivity but inverse to heat capacity
thermal diffusivity
123
sites with large __________ will accept or release heat from soil storage
relatively easily and thus exhibit _______ surface temperature variations over the
course of the day.
admittance, small
124
what is Qg
energy flow through the ground
125
What are the diurnal variations in soil depth?
During the warm season, soil temperature
decreases with depth, so QG is directed into
the soil and temperatures at the lower depth
increase (i.e., storage increases).
During the cool season, the surface is cooler
than lower depths, so QG flows towards the
surface and depletes storage.
126
energy flux = A x G
A = ability to transfer energy
G = gradient between two locations
127
soil heat flux and temp are governed by
- thermal admittance
- heat capacity
- thermal conductivity
- thermal diffusivity
