NOTES
Links to summaries of key issues for each topic
VISUALS
Links to images employed in lectures on a topic-by-topic basis
TEXT
Link to chapter outlines at online learning center at McGraw Hill.
NOTES
Links to summaries of key issues for each topic
|
|
The Physical Properties of Water (contd.)
|
Notes on Topic:
The notes represent summaries of key issues
for each topic
They emphasize the terminology used to describe
the various phenomena.
| 2. Transmission of
Energy: |
| Learning Objectives: |
-
How energy, light, heat and sound are transmitted through water
-
Measurement of these properties, their significance and uses
|
| Heat: |
-
Transmission by
-
conduction (direct transfer)
-
convection (movement)
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radiation (transferred through space).
-
Only surface ocean receives radiant heat, convection distributes heat.
|
| Light: |
-
Sun's heat as electromagnetic radiation from electromagnetic spectrum
-
gamma rays, X-rays, UV, visible, infrared, microwave, radar, radio/TV waves
-
Seawater transmits only visible light,
-
light is absorbed with depth, red before blue-green.
-
Light is refracted entering water
-
Light is absorbed and scattered causing attenuation (reduction)
-
Light penetration measured in oceans by:
-
light meters
-
Secchi disk lowered into water (standard device).
|
| Sound: |
-
Speed increases with temperature, pressure and salt content
-
Sound used to measure depth:
-
echo sounders, or precision depth recorders (PDR).
-
organisms may reflect sound: deep scattering layer (DSL).
-
Sonar:
-
directional pulses of sound
-
minimum velocity for sound at about 1km depth:
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sofar (sound fixing & ranging) channel
-
Efforts to use change in speed to measure ocean temperature change:
-
ATOC (acoustic thermometry of ocean climate)
|
| 3. Practical Considerations: Ice and Fog: |
| Learning Objectives: |
-
Nature of ice, iceberg and fog formation in the oceans
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Controls on their occurrence and features
|
| Sea Ice: |
-
Seasonally formed at polar latitudes
-
Sequence of slush, pancake ice, floes.
-
where ice is attached to land it is called fast ice.
-
Freezing seawater excludes salts, forms ice and salty water that sinks.
|
| Icebergs: |
-
Formed from glaciers by calving.
-
12% above surface
-
castle bergs from valley glaciers
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tabular bergs (even 155km long!) from continental ice sheets
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green icebergs with organic materials
|
| Fog: |
-
Clouds of water droplets.
-
Advective fog:
-
formed when water-saturated warm air moves over colder water
-
Sea smoke:
-
cold air moves over warm water
-
picks up water vapor and rises
-
cools to form ribbons of fog
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Radiative fogs:
-
moist air condenses at night
|
Department
of Geological Sciences,
1001
E. Tenth Street, Bloomington, IN 47405-1403
Phone:
(812) 855-5582 Last updated: 7 October 2000
Comments:
simon@indiana.edu
Copyright
2000, The Trustees of Indiana University
|
