EXAM 1 MATERIAL Flashcards
1
Q
what is a system?
A
an entity composed of diverse and interrelated parts that functions as a complex whole
2
Q
who was the guest on the podcast?
A
Helen czerski
3
Q
what would helen czerski want most in the future
A
a map of energy in the ocean
4
Q
where is active heat of the earth located?
A
the mantle
5
Q
where is primordial heat of the earth located?
A
the core
6
Q
what are components?
A
individual parts of the system
7
Q
what is the state of a system?
A
a set of attributes that characterize the system at a particular time
8
Q
what are couplings?
A
links between components of a system
9
Q
what is a feedback loop?
A
a self-perpetuating mechanism of change and response to change
10
Q
what is equilibrium?
A
at state at which the system will not change unless disturbed
11
Q
what is a perturbation?
A
a temporary disturbance in a system
12
Q
what is forcing?
A
a persistent disturbance to a system
13
Q
what are the two energy inputs that drive earth systems?
A
heat from the interior
heat from the sun
14
Q
what is the geosphere?
A
the solid earth
15
Q
what is blackbody radiation?
A
the hotter something is, the more electromagnetic radiation fluxes out of it
16
Q
what makes a greenhouse gas?
A
greenhouse gases absorb Infared radiation
17
Q
what mechanisms drive greenhouse gases ability to absorb Infared radiation?
A
- rotation
- vibration
18
Q
define rotation
A
molecules rotate at discrete frequencies conducive to absorbing IR frequency photons
19
Q
define vibration
A
molecules vibrate at different amplitudes conducive to absorbing IR frequencies
20
Q
what is the only layer of the atmosphere that convects?
A
troposphere
21
Q
why does the troposphere convect?
A
because it is getting heat from the surface
22
Q
how does a coupling work
A
A goes to B
23
Q
why does air move vertically?
A
uneven heating
24
Q
how does a feedback loop work?
A
A goes to B goes to A goes to B…
25
what does a negative feedback loop lead to?
stable equilibrium
26
what does a positive feedback loop lead to?
unstable equilibrium
27
how is positive coupling denoted
line with an arrow
28
how is negative coupling denoted?
line with a hollow circle
29
what does a positive feedback loop mean?
POS->POS
NEG->NEG
30
what does a negative feedback loop mean?
POS->NEG
NEG->POS
31
what is albedo?
how much light is reflected by the surface of a planet
32
why is earths interior hot?
- radioactive isotopes
- gravitatinoal differentiation (heat of accretion)
- radiogenic heat
33
describe the Nebular hypothesis.
- molecular clouds collapse
- conservation of angular momentum spreads cloud into a disk
- mass at center ignites
- sloar winds blow volatiles out of inner disk
34
what are volatiles?
elements/compounds that DO vaporize easily
35
what are refractories?
elements/compounds that DO NOT vaporize easily
36
what is planetary differentiation?
- denser elements (iron/nickel) sink to the core
- lighter elements stay in the outer shell
37
how do we know the earth interior is hot?
hot stuff comes out of the surface
38
what is convection?
transfer of heat by a circulating mass of fluid driver by density differences
39
what is magnetic dynamo
convection of liquid iron generates magnetic field
40
what is the magnetosphere
area dominated by earths magnetic field that deflects charged particles
41
how do we know the mantle is convecting?
seismic anisotropy
42
what is electromagnetic radiation?
waves of the electromagnetic field propagating through space.
43
what is a blackbody?
something that emits electromagnetic radiation with 100% efficiency
44
what is Wein's law?
peak wavelength is inversely proportional to a body's absolute temperature
45
what is stefan boltsmann's law?
energy emitted by a blackbody is
related to the fourth power of the body’s absolute
46
what is flux?
the amount of energy that passes through a given area per unit time.
47
what is insolation?
the amount of solar radiation that reaches earths surface
48
what is earths albedo?
roughly 0.3
49
what is the greenhouse effect?
mechanism by which a planets surface is warmed by Infared-absorbing gases in its atmosphere
50
how much does the greenhouse effect warm earth?
about 33 degrees Celsius
51
what is the composition of earths atmosphere?
- Nitrogen (78%)
- Oxygen (21%)
- Argon (0.9%)
52
what are the major greenhouse gases?
- water vapor
- carbon dioxide
- methane
53
what are the layers of the atmosphere? (bottom-top)
- Troposphere
- Stratosphere
- Mesosphere
- Thermosphere
54
where does 'weather' occur?
the Troposphere
55
what is latent heat transfer?
energy released or absorbed by phase changes
56
what is the orographic effect?
as air rises over high topography, air cools and condenses
57
what layer of the atmosphere does temperature increase with altitude and why?
stratosphere
because Ozone absorbs UV radiation, thereby heating it
58
what is an RCM
Regional climate model
59
what is an RCM used for?
estimating the effects of increasing greenhouse gases on global average temperature
60
what is one limitation of an RCM?
does not account for feedbacks
61
what are some basic climate feedbacks?
- water vapor feedback
- snow ice-albedo feedback
62
how/why does air move horizontally?
air moves from high pressure-low pressure.
63
where in the world is most energy absorbed and why?
equator, because it receives most direct sunlight
64
what is the Coriolis effect?
- flows moving from LOW to HIGHT latitude- deflect toward direction of rotation (RIGHT)
- flows moving from HIGH to LOW latitude- deflect against direction of rotation (LEFT)
65
what is the ITCZ?
inter-tropical convergence zone
66
what does the ITCZ mean?
convergence=low pressure
divergence=high pressure
67
what does ITCZ determine?
where wet/dry zones will be seasonally
68
why cant the ocean circulate the same way as the troposphere
troposphere is heated from bottom up
ocean is heated from top down
69
what is ocean upwelling?
bringing water from the deep ocean up
70
what is ocean downwelling?
taking water from the surface and circulating it down
71
what is a pycnocline?
a steep density gradient in the ocean
72
what is the significance of a pycnocline?
marks the transition between the surface and the deep ocean.
73
what drives deep ocean circulation?
density gradients
74
what are the two sites (currently) where deep ocean water mixes?
Antarctic bottom water (ABW)
North Atlantic deep water (NADW)
75
why is water special on earth?
it can naturally exist in all three states of matter
76
when is the NADW believed to have begun?
15-20 Ma
77
how do we know earths climate changes over time?
vegetation records in the sediment?
78
what is planetary eccentricity?
how circular the earths orbit around the sun is
79
what is planetary obliquity
angle of earth's axis of rotation
80
how does obliquity effect seasons?
more tilt = more extreme seasons
less tilt = less extreme seasons
81
what is planetary precession?
the wobbling of earths axis of rotation.
82
what causes precession?
tidal forces
83
what are the timescales for orbital forcings?
Eccentricity: 100,000 year cycles
Obliquity: 40,000 year cycles
Precession: 23,000 year cycles
84
what was the great American biotic interchange?
animals were free to move to/from north/south America when the central American seaway closed.
85
during the GABI, more animals from north America moved to south rather than vice versa, why?
north American life had much more evolutionary competition, south American life could not compete
86
why is latent heat important?
one of the dominant mechanisms of energy transfer across the surface earth.
87
what are isotopic records?
changes to the water cycle/sea level
88
what is delta O18
Ratio of stable isotopes of Oxygen 18/16
89
why is the ocean salty?
rain picks up sodium ions, deposits them in the ocean, evaporation concentrates it
90
why does asia have a monsoon season?
orographic effect dumps moisture at the foot of the plateau
91
how do we know the Asia monsoon has evolved through time?
thermochronology tells us when the rocks were eroding
92
what does saharan dust do?
- decreases incident solar radiation
- seeds cloud formation
93
what are the three atmospheric circulation cells, from equator outward?
Hadley, Ferrell, polar
94
what direction does water rotate in the northern hemisphere?
clockwise
95
what direction does water rotate in the southern hemisphere?
counterclockwise
96
is the ITCZ at a high or low pressure zone
low pressure
97
what are equilibrium states?
a stable set on conditions in the system
98
what isotope dominated heat generation in first 1.5 billion years
potassium 40
99
what isotope dominated heat generation now
thorium 232
100
what are components of the earth systems
atmosphere
sun (energy source)
101
what are elemental sources of radioactive heat
uranium 235/238
potassium 40
thorium 232
102
how does convection drive plate tectonics?
slab pull at subduction zones
103
what drives all everything but tectonics
sun
104
what drives pate tectonics
heat transfer within the solid earth
105
feedback loop is negative ONLY if both couplings cancel each other out
106
why is plate tectonics crucial?
recycles elements
builds mountains
107
why is there a gradient in solar energy from poles to equator
more sunlight at equator, less at poles
108
what is the angle of incidence?
angle at which sun hits earth
higher is more direct contact
109
what factors determine the temperature of the earth?
solar flux
albedo
greenhouse gas
110
what molecules absorb greenhouse gases
methane
co2
water vapor
111
how do we know what climate cycles looked like in the past?
oxygen isotopes
112
what happens to oxygen when iced sheets are built
oxygen18 (denser) increases
113
what drives surface ocean movements
wind
114
how deep is surface ocean heated
100m
115
what increases salinity
evaporation
freezing
116
how long does it take to mix atmosphere
a few months
117
how is the stratosphere stratified
ozone is generated at stratosphere and heated from the top
118
what process happens at top of troposphere
the level at which Infared is re radiated out
119
what are the two things used to describe climate zones?
temperature, precip
120
how is the quaternary defined?
the period of modernal glacial/interglacial cycles
121
why northern hemisphere special?
more surface area, mechanism to bring moisture to high latitudes
122
what are the forcings that drive climate cycles
orbital mechanics
123
what conditions dictate if building ice sheets
- eccentricity (low=more stable)
- how hot the summer is
124
how are glacial periods marked on a graph
low points are glacial periods (more O18)
high points are interglacial periods
