Exam 1 Flashcards
(160 cards)
1
Q
What is Geography
A
-The science that studies the relationships among natural systems, geographic areas, society, cultural activities, and the interdependence of all these over space (Christopherson 6th ed., p. 2)
-The branch of knowledge that deals with the Earth’s surface, its form and physical features, natural and political divisions, climate, products, population, etc. (New Shorter Oxford English Dictionary)
2
Q
Interactive cartography
A
ie google maps
3
Q
Geography’s sub disciplines
A
Physical Geography, People and Enviornment, Human Geography, Cartography and Geographic information science
4
Q
Physical Geography
A
studies the earth system and its physical
and biological subsystems
5
Q
People and Environment
A
studies the interactions between
humans and the natural world
6
Q
Human Geography
A
studies the patterns and drivers of human
social organization across space and time
7
Q
Cartography
A
develops principles and techniques for
visualizing and analyzing spatial data
8
Q
System
A
composed of individual but connected parts that function as a complex whole
9
Q
How many sub systems does the earth system have
A
15
10
Q
Closed system
A
system that transfers energy, but not matter, across it’s boundary to the surrounding environment
11
Q
Open system
A
allow energy and mass to pass across the system boundary
12
Q
Is earth a closed or open system?
A
Both; closed with respect to matter(nothing disappears, uncontained matter spreads out), open in respect to energy
13
Q
systems are dynamic
A
elements are constantly changing and interacting with one another over time
14
Q
External forcings
A
affect a system, are not affected by it
15
Q
internal feedbacks
A
interlinked interactions among components within a system
16
Q
Feedback loops
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processes interacting within systems that form looped change of cause and effect
17
Q
State variables of feedback loops
A
variables that describe state of system
A B
18
Q
Couplings of feedback loops
A
mechanisms linking variables, can be positive or negative
A->B
<-
19
Q
Positive couplings
A
A and B go in same direction (i.e. if A increases, B increases)
20
Q
Negative couplings
A
A and B go in opposite directions (i.e. if A increases, B decreases)
21
Q
Ice and snow extent <-> Temperature
A
Example of state variable and coupling
22
Q
Albedo
A
Reflectivity of a surface
23
Q
Earth system example of feedback
A
Albedo-ice-temerature
24
Q
Explanation of Albedo-ice-temp feedback
A
- World getting colder
- Ice sheets grow
- Albedo increases
- More heat reflected
away - World gets colder
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what do Positive feedbacks do?
Amplify original tened, promote instability and rapid change
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What do negative feedback loops do
counteract original trend, stabilizing
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Energy
the ability to do work, or change the state of matter
28
Electromagnetic energy
vibrating electronic force fields composed of waves of varying frequency and wavelength
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Frequency
how often a recurring event occurs in a measured amount of time
30
Insolation
INcoming SOLar radiATION (almost all of earths energy comes from the sun
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Shortwave radiation
Higher frequency, higher energy per photon (from right of optical band to the left)
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Longwave radiation
Lover frequency, lower energy per photon (right of optical band)
33
Outgoing longwave radiation
Infrared radiation, emitted by the earth
34
What form of energy is both entering and exiting the earth system
Electromagnetic energy
35
Blackbodies
Perfectly emit and absorb EMR, no matter the wavelength (not all objects are perfect blackbodies)
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Properties of blackbodies (wien's law)
objects of different temp emit spectra that peak at different wavelengths;
-hotter objects emit most of their radiation at shorter wavelengths~appears blue
-colder objects emit most of their radiation at longer wavelengths~appear redder
37
Properties of blackbodies (Stefan-Boltzman law)
Amount of EMR emitted by a blackbody is proportional to the fourth power of the temperature
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energy (EMR) emitted by sun
72 million watts/m^2
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energy (EMR) emitted by earth
240 watts/m^2
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what type of wavelengths does the sun emit at ?
shorter wavelengths
41
Earth's energy balance
Earth's energy budget is balanced between incoming shortwave and outgoing longwave radiation
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Insolation distribution by latitude
because earth is curved, more direct insolation at equator and more diffuse insolation at poles *Low latitudes receive 2.5x more radiation than high lats
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Insolation after passing though atmosphere
Becomes more complex at top of atmosphere due to cloud, gas, and atmospheric absorption and reflection
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What is the trend of net radiation in the top atmosphere? (incoming-outgoing)
Positive net radiation in low latitudes (more incoming than outgoing), negative net radiation in high latitudes (more outgoing than incoming)
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The trend of net radiation energetic imbalance in the top atmosphere does what?
The driver of atmospheric and oceanic circulation
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4 key factors of earth-sun geometry and the seasons
1.)Earth spins on it's axis: 1x per day
2.)Earth orbits around the sun: 1x per year
3.)Earth's axis is not perpendicular to it's orbital plane: 23.44 degrees angle to vertical
4.)Axis orientation is fixed: North Pole points to Polaris star
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Why do seasons occur?
Hemispheres alternately point towards/away from the sun
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Why does insolation vary by latitude and season?
Changes in daylength and solar angle as earth orbits around the sun
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Seasonal variation in daylength by latitude
Latitude: 90N 40N 0 40S 90S
Dec. 21Solstice: 0hrs, 9hrs, 12hrs, 15hrs, 24hrs
March 21Equinox: 12hrs 12hrs 12hrs 12hrs 12hrs
June 21Solstice: 24hrs 15hrs 12hrs 9hrs 0hrs
Sept. 22Equinox: 12 hrs 12hrs 12hrs 12hrs 12hrs
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"Special" latitudes
-Arctic & Antarctic Circles: 66.56ºN & 66.56ºS
furthest south (north) latitude to experience 24 hours
day/night
-Tropics of Cancer and Capricorn: 23.44N & S
latitudes at which sun is directly overhead on solstices
51
Earth's rotation=what shape?
ellipse
52
What changes in earth's orbit cause ice ages?
-Eccentricity (more circular<->more elliptical)
-orientation of earths axis
-Tilt
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Why do we need the atmosphere? (6)
* Provides air we breathe
* Filters incoming and outgoing EMR
* Shields us from high-energy, damaging EMR
* Waste repository
* Transports heat and moisture
* Links land and oceans
54
Basic atmosphere facts (5)
1. The atmosphere is a gas
o Compressible
o Obeys (nearly) the Ideal Gas Law
o Fluid – moves around
2. Not much of it!
99.9% of atm. within 50 km vs. 6370 km radius earth
3. A mixture of many different molecules
4. Interacts with incoming and outgoing EMR
5. Heated at bottom (and in middle) → unstable
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Ideal gas law
PV=nRT
(Pressure)(Volume)=(number of molecules)(gas constant)(Temperature)
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State variable
characteristic or attribute that describes the current condition of a geographic location or region
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Pressure
Force exerted by kinetic motion of gas molecules
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Density
mass per unit volume (n/V)
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Why do density and pressure decrease as hight increases?
o Gravity pulls air down
o Atmospheric pressure pushes back
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Surface air pressure
1013.2 millibars
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four zones of atmospheric thermal pressure
Thermosphere, mesosphere, stratosphere, troposphere
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Tropospheric lapse rate
rate of temperature decreases with increasing elevation
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Normal lapse rate
6.4 degrees C/km or 3.5 degrees F/1000'
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Stability
tendency of air mass to remain in place (vs. rising/falling)
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Key facts of atmospheric stability
1.) warm air is less dense than cold air (think hot air balloon)
2.)Atmosphere is stable when dense air is underneath less dense air
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Is troposphere stable or unstable
Unstable
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is stratosphere stable or unstable
stable
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Three major gasses of atmospheric composition
78%Nitrogen (N2) 21%Oxygen (O2) 0.9%Argon(Ar)
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What percent of the atmosphere do the 3 major gases make up?
99.9% (pretty consistently distributed around the world)
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Trace gases
gasses present in small amount in the atmosphere
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Trace gases in the atmosphere
0-4% water vapor (H2O)- varies among dry and wet places
420ppm Carbon Dioxide (CO2)- rising bc fossil fuel burning
1.8ppm Methane (CH4)- fossil fuel burning
0.6ppm Ozone (O3)- was declining, now stabilizing
Concentrations vary
there are many more
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aerosols
small particle suspended in the atmosphere
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What do aerosols affect?
Passage of sunlight, and cloud formation
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Sources and types of aerosols
* Mineral dust
* Sea salt
* Volcanoes
* Fires
* Air pollution
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effects of environmental changes caused by people (anthropogenic) on the atmosphere
Additions (pollutants)
Carbon dioxide
Methane
Carbon monoxide
Nitrogen oxides
Volatile organic compounds
Ozone (troposphere)
Peroxyacetyl nitrates
Sulfur oxides
Particulates
Losses
Ozone (stratosphere)
Fuel consumption, transportation, industrial processes are the heavy hitters
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What does the Ozone layer do?
Shields us from UV radiation
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Where is the most Ozone?
Stratosphere (Pollutant in troposphere)
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How is Ozone destroyed?
By chemical reactions with chlorine (chlorine catalyzes the destruction of Ozone)
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How was chlorine released to atmosphere?
released to atmosphere through breakdown of chlorofluorocarbons (CFCs and HCFCs), once used, now banned.
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What were CFCs and HCFCs used in?
Aerosols and air conditioning units
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Ozone hole
Natural phenomenon- a region over antartica of largely depleted ozone levels
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What is Ozone recovery an example of?
a successful linkage between science and policy
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What is the solar constant value
1372 W/m^2
84
What are the 5 EMR interactions with matter
1.)Emission- convert heat energy to EMR
2.)Transmission-when EMR waves pass through an object without being absorbed or scattered
3.)Absorption- converts EMR to heat energy
4.)Reflection-Sends the EMR waves received back out
5.)Scattering-when the energy carried is deflected in other directions \
85
What ode water Albedo depend on?
solar angle- High-angle=sort of perpendicular, low-angle=oblique
86
What time of the year is there the most albedo on the poles?
January
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At what latitude is relatively stable albedo maintained?
0/equator
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diffuse radiation in the atmosphere
when sunlight is scattered in various directions as it passes through the atmosphere- therefore having more interaction with air molecules and particles before interacting with earth's surface
89
Direct radiation
radiation that has not been scattered before interacting with earth's surface
90
Does the moon have scattering radiation?
no, no atmosphere to scatter the radiation
91
Raleigh scattering
short wavelengths scatter more easily than long
92
Why is sky blue?
Blue light scatters more easily, imparts blue color to atmosphere
93
Why are sunsets red?
When the sun is on the horizon, the rays must travel longer distances. As they travel, the blue/green light is scattered away, leaving red light
94
what attributes most to atmospheric shielding?
scattering
95
Are rays only scattered in the atmosphere?
no, absorption also occurs-i.e ozone absorbs UV radiation
96
Greenhouse effect
Atmosphere is (mostly) transparent to visible light and (mostly absorptive of infrared EMR- gases in the atmosphere trap the sun's heat, which is delivered in infrared rays
97
Global energy balance and greenhouse effect
Actual temperature: 15 Degrees C
Temperature if atmosphere not present: -19 degrees C
Greenhouse effect:
34º C
98
What percent of air does nor interact with radiation?
99%
99
Why do some molecules absorb infrared and not others?
dependent on molecular symmetry and charge imbalances
100
Primary absorber of infrared
Water Vapor, CO2 does as well
101
Clouds and Energy budget
clouds both reflect sunlight and trap incoming solar radiation (opposed effects on earth's energy budget)
102
General rule of clouds and warmth of earth
high clouds warm earth (trap heat emitted by earth's surface and re-emit it), low clouds cool earth (reflect a large portion of incoming light)
103
Direct effect of aerosols in the atmosphere
Absorb and scatter shortwave radiation- warms atmosphere, cools earth
104
indirect effect of aerosols
nucleation sites for water droplets-cloud formation
105
Heat energy
The kinetic energy of atoms- more energetic atoms move faster
106
Sensible heat
Heat energy that results in a change in temperature. Corresponds to the vibrational energy of molecules. Can be measured by thermometer.(moves up or down in temp)
107
Latent heat
Heat energy that results in a change in phase: solid>liquid>gas (stays stagnant in temp)
108
The two forms of heat energy
Sensible and latent
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The mechanisms for transferring heat energy
Conduction, Convection, Advection
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Conduction
Heat transfer by contact (pan heating from being ona burner)
111
Convection
heat transfer by movement of fluid masses (primarily vertical) ((hotter areas rise, colder areas sink)) (((in a pot of boiling water, the water heats, rises, cools, falls-circulation)
112
Advection
A convection, but mainly horizontal
113
How does earth's surface transfer latent and sensible heat energy?
conduction, convection, and advection EX. the wind being moved horizontally is result of advection, radiation from the ground acts as a conductant to wind-making it warmer, causing it to rise and vertically mix into cooler air then fall which is convection.
114
The three components of planetary energy balance
Shortwave EMR, Longwave EMR, and Heat energy
115
The three layers of planitary energy balance
Top of atmosphere, Atmosphere, Earth's surface
116
Is the earth in energetic balance?
YES!!!
117
attributes of outgoing shortwave radiation from top of atmosphere
Highest values in areas of high albedo
-Tropical clouds
-mid/high latitude water
-polar ice
118
attributes of outgoing longwave radiation from top of atmosphere
Highest in low latitudes Except for cloudiest areas
119
In what areas is annual surface losses of latent heat highest?
warm and wet (latent heating requires water to evaporate)
120
In what areas is annual surface looses of sensible heat highest?
Warm and dry -sensible heating will be higher when latent is low
121
Global temperature relating to latitude
Temperatures are highest near equator (sunlight most concentrated at equator)
122
Global temperature in relation to elevation
highest at bottom of atmosphere (earth's surface heated by sunlight)
123
What is the trend in interaction between elevation and latitude temperature on mountain glaciers
The caps become smaller as the mountains get closer to the equator (more direct sun heat from both the earth and the sun)
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global temperature in relation to temperature seasonality
closely tracks insolation
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global temperature in relation to oceans vs. Land
Land heats/ cools more quickly than oceans
126
why does land heat/cool more quickly than oceans?
-water has higher heat capacity (specific heat capacity of water is higher than that of soil)
-sunlight distributed over greater volume (depth) in ocean
127
Do those living near a maritime climate experience lower seasonality than continental climates no matter the latitude?
yes
128
Global temperature in relation to atmospheric and ocean transport of heat
The constant movement of the ocean and the atmosphere consiquently distribute heat
129
Why does atmospheric circulation matter?
-Transports heat energy
-transports water
-our day-to-day weather
-Extreme events:storms and hurricanes
130
Four fundamental forces that drive atmospheric circulation
-Gravity
-Pressure gradient force
-Coriolis "force"
-Friction
131
How do gravity and atmospheric pressure interact?
Gravity pulls air down, Atmospheric pressure pushes back
132
Pressure gradient force
-Air forced from high pressure to low pressure
-fastest wind speeds when pressure gradients are steep
133
Where are the strongest winds?
In areas of a steep pressure gradient
*winds not perpendicular to isobars
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in what direction does wind flow?
From high pressure to low pressure
135
Low pressure system
An area where atmospheric pressure is significantly lower than the surrounding area, causing air to converge and rise upward. (circulates counterclockwise in northern hemisphere)
136
Coriolis Force
acts perpendicular to the direction of travel; deflects moving objects (due to the earth's rotation, air is deflected to the right in northern hemisphere, and left in southern hemisphere
137
Momentum
Mass*Velocity Momentum is always conserved in a closed system (mass remains constant and net external force is zero)
138
Angular momentum
momentum around a rotational point (angular velocity*Mass)
((is always conserved in a closed system))
139
Rotating frame of reference
When looking from above, the thing thrown from the center looks like it moves with the rotation, when looking from the side, it looks like goes straight
140
Where does the Coriolis 'force' emerge from?
Earth's rotation and conservation of momentum
141
Is angular velocity (and thus momentum) lower at the equator than ples?
No, it is higher.
142
What are the consequences of a higher angular velocity at the equator?
-Flying objects will have the momentum of their starting location, which may differ from the earth they travel over
-^causes them to be deflected as they move (planes have to accommodate for this)
--Northern Hemisphere:deflected to the right
--Southern Hemisphere: deflected to the left
143
Intended path vs. actual path
Intended path is straight, actual path is curved (more so as headed to poles)
144
Velocity and coriolis force
Velocity is proportional to strength of coriolis force: the higher the velocity the more affected by the coriolis force
145
Latitude and coriolis force
strength of coriolis force is proportional to latitude: zero at equator, strongest in high latitudes-air masses rotate more at high latitudes
146
Why does the strength of the coriolis force vary with latitude?
Vorticity
147
Vorticity
The local spinning motion of a fluid
148
Why does Vorticity happen?
the earth rotates and it's surface is curved
149
Where is vorticity high
at the poles
150
is the coriolis force dependent on voticity
yes, hence coriolis force is high at poles and low at equator
151
How does friction force act to the direction of travel?
opposite
152
what is the effect of friction force on an object?
It slows the object
153
Where is friction most significant?
at earth's surface (more particles in the air, more buildings/mass/movement)
154
where is friction the lowest?
The upper atmosphere
155
Geostrophic flow
Wind patterns that result from interaction between Coriolis and PG force (no friction)
156
How does Coriolis force affect geostrophic flow?
it deflects air moving in response to pressure gradient force
157
In what way does air move in relation to pressure gradient?
Parallel, not across
158
Where are the strongest winds
In areas of steep pressure gradient
159
Low pressure zone
-air flows inward (converges)
-cyclonic rotation (counterclockwise in Northern Hemisphere)
160
High pressure zone
-air flows outward (diverges)
-anti-cyclonic rotation (clockwise in Northern Hemisphere)
