Transcript Introduction - San Jose State University

MET 112 Global Climate Change
Review – Midterm 1
Eugene Cordero
San Jose State University
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MET 112 Global Climate Change
Lecture 2
Lecture 3
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Solar Radiation (Sunlight)
 Sunlight is primarily made up of the
following:
– Visible Light (44%)
– Infrared Radiation (48%)
– Ultraviolet Radiation (7%)
Unit: 1 m =
0.000001 m
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Solar vs. Terrestrial Radiation
 The sun is much
hotter than planets;
therefore, sunlight
consists of shorter
wavelengths than
planetary radiation;
 Thus …
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Explain what would happen to
these energy estimates if the
Earth’s albedo was to
increase.
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Some surface
radiation
escapes to
space
Most
outgoing
longwave is
absorbed in
atmosphere
(by
greenhouse
gases)
Longwave radiation is
emitted from surface.
Some
atmospheric
radiation
escapes to space
Greenhouse
gases emit
longwave
upward and
downward
Some
atmospheric
radiation is
absorbed at the
surface
Comparison of Earth and Venus
Venus
Earth
Venus is completely covered by highly reflective
clouds; Earth is partially covered by clouds. Which
planet has a higher albedo? _______________
Venus
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Lecture 4
Why do we have seasons?
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Annual Surface Temperature
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Dry
Humid
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Lecture 5
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Water freely
evaporating and
condensing
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Lecture 6
Temperature
Graph
Source:
http://www.ruf.rice.edu/
~leeman/aNR.html
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SOLAR ACTIVITY
 Sunspots are the most
familiar type of solar
activity.
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Earth’s orbit: an ellipse
• Perihelion: place
in the orbit
closest to the
Sun
• Aphelion: place
in the orbit
farthest from the
Sun
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Eccentricity: period ~ 100,000 years
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Precession: period ~ 22,000 years
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Axis tilt: period ~ 41,000 years
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Temperature: the last 400,000 year
From the Vostok ice core (Antarctica)
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Lecture 7
Climate Feedbacks
 Positive feedback:
– initial change reinforced by another process.
 Negative feedback:
– initial change counteracted by another process.
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Lecture 8
The Earth’s history can be
characterized by different
geologic events or eras.
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Short Term Carbon Exchanges
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Silicate-to-Carbonate Conversion
Rain
2. Acid
Dissolves
Silicates
(carbonic
acid)
Land
1. CO2 Dissolves in
Rainwater
3. Dissolved Material Transported
to Oceans
4. CaCO3 Forms in
Ocean and Settles to
the Bottom
Calcium carbonate
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Subduction
Definition: The
process of the
ocean plate
descending
beneath the
continental plate.
During this
processes, extreme
heat and pressure
convert carbonate
rocks eventually
into CO2
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Organic Carbon Burial Process
O2
CO2
Removed
by PhotoSynthesis
CO2 Put Into
Atmosphere by
Decay
C
C
Some Carbon
escapes
oxidation
C
Result: Carbon into land
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Oxidation of Buried Organic Carbon
Atmosphere
CO2
O2
C
Buried Carbon
Result: Carbon into atmosphere (CO2)
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The Long-Term Carbon Cycle
(Diagram)
Subduction/
Volcanism
Atmosphere (CO2)
Ocean (Dissolved CO2)
Biosphere (Organic Carbon)
Silicate-toCarbonate
Conversion
Carbonates
Organic
Carbon
Burial
Oxidation
of Buried
Organic
Carbon
Buried Organic Carbon
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Lecture 9
Gaia Hypothesis
(proposed in
late 70’s)
Life collectively has a significant
effect on earth’s environment
Atmosphere-Biosphere interactions are
Dominated by negative feedback
Goes beyond
simple interactions
amongst biotic and
abiotic factors
Evolution of life and Evolution of
its environment are intertwined
Life optimizes the abiotic environment
to best meet biosphere’s needs
Biosphere can be modeled as a
single giant organism
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With Daisies
Temperature
80 -
•
40 -
•
•
•
•
•
•••
Daisies
5-
•
•
2 billion years
-20 -
Solar Luminosity
(Time)
•
•