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CLIMATE

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Title: CLIMATE


1
CLIMATE
2
After the surface of the earth cooled and surface
crust (lithosphere) formed, the planet surface
took on something of the look it has today
land, air, oceans (lithosphere, atmosphere,
hydrosphere)
3
The temperature at the ______ of the earth is
determined, not by geology of the core but
primarily by energy coming from outside the
_____.
4
NASA
5
What is energy?
The capacity to do work (move mass) and transfer
heat
Two main forms 1. ________ a mass moving
2. _________ stored in a structure, molecule,
nucleus - able to become kinetic under right
conditions
6
Where does the sun get its energy? Nuclear
fusion
Atoms of hydrogen fuse to form __________
releases large amounts of energy
9-18/10-19
Requires extremely high pressure temperature
conditions, such as exist in the sun. Fusion
reactions further _______ these temperatures.
7
How does the sun supply energy to the earth?
The sun is a hot body. Hot bodies emit
___________ waves (EM), as a function of their
temperature.
8
What are electromagnetic waves? Light.
Physicists tell us that light has both ____ and
particle properties. The particles are called
photons, the wavelength measures their energy
level.
The energy of light is determined by
___________   hc E energy E ------ h
Plancks constant ? c speed of light ?
wavelength
9
There is a broad spectrum of wavelengths and
energies
Shorter waves _______ energy
10
Visible light is a small segment of the
electromagnetic spectrum
11
The sun emits electromagnetic waves as a function
of its temperature. Its heat results from
nuclear fusion (H to He)   Peak (intensity)
wavelength of a radiating body (Weins law)   Max
? 2.88 x 106 / T (oK) T temp   Sun
temperature 5750 oK   Suns max ? (2.88 x
106)/5750 500 nm (__________)   Interestingl
y, at planet formation, sun 25 ________ max ?
670nm orange Stars heat up as they age
(why?)
12
Total light energy is distributed around this
peak wavelength
2-6
13
Much of the energy hitting the earth is in the
______ spectrum
Is this just a lucky coincidence?
14
The density (photons/m2) _________ with distance
from the sun
The energy density intercepted by the earth is
determined by the distance to the sun.
Solar _________ 2 cal/cm2/min 1 cal/cm2/min
reaches surface
Varies through the year orbit an _________.
15
The total energy intercepted by the earth a
function of area of the profile.
(earth radius 6378km)
Solar constant x area
2.495 x 1018 cal/min
This energy input creates a surface temperature,
a dynamic equilibrium a balance of inputs and
outputs
2-10
16
What is a dynamic equilibrium?
Equilibrium describes an entity that appears
_____________ over time, a steady state.
For example, a tub of water half full.
There are at least two ways that tub could stay
half full. 1. Turn off the tap - it sits there
unchanging. 2. Leave the tap on, but open the
drain.
2 is a dynamic equilibrium
17
Obviously, a key relationship for a dynamic
equilibrium is
________ __________
What happens to an equilibrium if you increase
inputs? Does the water level go up, down, stay
the same? What did you assume to decide on your
answer?
18
We can easily imagine at least three ways to get
a dynamic equilibrium in our bathtub
1. ________ output, ________ input adjust input
to match output. Total amount in tub is
irrelevant. (could also have fixed input, match
output) 2. Output __________ as input
increases. a. tub is fixed size, overflow
input, tub full. b. output increases as amount
in tub increases, output eventually matches input
What kind of dynamic equilibrium is earth surface
temperature?
19
Surface temperature is a balance of solar inputs,
reflectance, _________ and re-radiation (into
space).
Re-radiation is also EM waves, at _____ wavelength
If no re-radiation, no heat loss, earth
____________.
As the earth heats up, it re-radiates more
(output increases)
Type 2b dynamic equilibrium
Higher input, _________ equilibrium temperature.
20
If sun was cooler in past, earth was __________,
yes?
Maybe, but this ignores the greenhouse effect
Components of atmosphere absorb outgoing
wavelengths, re-radiate back to _____, increase
heat before leaving at lower energy.
21
Depends on composition of the atmosphere.
Carbon dioxide, ________, __________, and nitrous
oxide are strong greenhouse gases. Early earth
atmosphere was _____ in these, so may have been
as warm as or warmer than today (est. 23oC).
22
Question what would be an equivalent of the
greenhouse effect in the bathtub analogy?
23
Estimates of global temperature indicate lots of
changes during the history of the planet.
Barry Saltzman, Dynamical Paleoclimatology
Generalized Theory of Global Climate Change,
Academic Press, New York, 2002, fig. 1-3.
24
Including _________ that lasted many thousands
of years
NOAA
Much of the earth was covered with ice packs
miles deep, that altered the landscape and
created lakes and rivers when they melted.
25
The most recent glacial period began about 70,000
years ago, and ended about _________ years ago.
26
These changes in ice pack directly affect the
amount of liquid water and therefore ocean levels.
27
12-17/12-16
Greenhouse gas composition is one factor
affecting this temperature variation
12-16/12-15
28
12-17/12-16
29
Dynamical systems like surface temperature can be
difficult to understand and predict because of
the interconnectedness of the component processes.
These connections create feedback loops, or
causal cycles rather than simple causal chains
like A affects B affects C.
For example, two simple feedbacks

1. ________ feedback increase in A increases B,
which decreases A. homeostatic, stable
_
2. _________ feedback increase in A increases
B, which further increases A. Blowup or
collapse.


30
In earth temperature regulation, we have already
seen an example of each
1. Re-radiation _________ feedback. Increasing
solar input (heating) results in increased
radiation to space (cooling)

Earth temp.
Re-radiation
_
2. Water Vapor __________ feedback. Increased
temperature increases evaporation, increased
water vapor in atmosphere increases greenhouse
effect.

Earth temp.
Water vapor

31
But also, increased water vapor in the atmosphere
tends to increase cloud cover, which increases
________ and thereby decreases earth temperature

What would you call this??
Earth temp.
Water vapor


_
In the bathtub analogy, what is equivalent to
cloud cover?
Cloud cover
Predicting cloud cover is an important source of
_________ in climate modeling.
32
Solar energy density is not even across the earth
or through the year climate varies from place
to place.
_____ in winter, _____ at poles.
Opposite seasons in the northern and southern
hemispheres
33
Three basic ways heat is transferred 1.
Convection movement of heated fluid due to
density 2. Conduction direct contact
molecular collisions 3. Radiation EM waves
from hot body
34
Wind and ocean currents move heat around
_________ cells warm moist air rises at
equator, cools, rains high dry air moves toward
poles, cools and sinks.
12-3
Six Hadley cells in earth redistribute heat and
moisture
35
Wind and ocean currents move heat around
_____ winds form due to earths rotation faster
at equator than at poles
Which way does the earth turn?
36
Wind and ocean currents move heat around
Similar forces generate ocean currents
differences in temperature, wind, topography,
_______, earths rotation
These currents can alter ________ on land in
coastal areas
http//earth.usc.edu/stott/Catalina/Oceans.html
37
Cold, salty water in the North Atlantic sinks and
flows south into the Pacific, eventually warms,
rises and returns.
38
Topography can also alter climate 1. High
altitude air is ________ lower pressure 2.
The rain shadow effect ______ on the lee
side
39
Weather large air masses generally moving and
interacting local climate conditions frequently
change
Fronts where different air masses contact,
energy is transferred.
______ front moving warm air mass contacts a
cold mass, it rises up, widespread clouds.
______ front moving cold mass drives under a
warm air mass, sudden cooling, strong winds and
rain.
40
Tornadoes
High energy concentration can result in special
storms with spiraling high velocity winds
Hurricanes (Typhoons)
41
___________ cycle
_____ driven evaporation of water into air begins
a cycle as the warm moist air rises, condenses to
clouds and rain, which returns directly to
surface water (lakes, oceans) via rivers and
underground (ground water flow), and so on.
2-19/2-25
42
Energy flow and material cycles
The water cycle is an example of a general
natural pattern on earth the linkage of the flow
of energy and cycling of materials
EM (Space)
Water vapor
Energy flows
Water cycles
Liquid Water
EM (Solar)
43
12-2
These multiple forces drive variation in climate
across the world
44
Conclusions earth a dynamic process, has
history geologically active rock
cycle temperature a balance of factors solar
energy drives climate patterns water cycles
through its states flows of energy and cycles of
materials interaction of geological and solar
energy
NOAA
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