Transcript ABC`s to Oceanography - University of Delaware

eteorology
 Meteorology is the study of the
atmosphere and the interaction
between the atmosphere and the
land, ocean, and life
 The physics, chemistry, and unique processes of Earth’s atmosphere are
explored in great detail by meteorologists
•
Meteorologists try to completely understand the atmosphere, so they can predict
how it is going to behave
umerical Models
Simulation of Global
Ocean Circulation
 Mathematical calculations that provide oceanographers
with detailed views of circulation in the oceans
 Two main types of numerical models:
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Mechanistic models – simplified models that examine the
mathematics behind physical processes
Simulation models – complex models that can be used to
calculate the realistic flow in the ocean
http://www.dkrz.de/
 What are some of the advantages and disadvantages of using numerical models?
•
•
Advantage:
• The models can be used to simulate realistic flow and predict future flow in the
ocean
Disadvantage:
• The models cannot give completely accurate descriptions of the flow in the ocean
cean
Fast Fact:
The average
depth of the
ocean is 3.7 km
(about 2 miles)
http://www.ngdc.noaa.gov/
 A large body of salt water
 Millions of years ago Earth’s surface was very hot and all the water boiled away
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•
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Volcanoes released large amounts of steam into the atmosphere
As Earth cooled, the steam changed to water vapor, and condensed to raindrops
Rain fell thousands of years filling all the cracks on Earth with ocean water
 What impact does air-sea interaction have on Earth?
Did you know?
The pressure at the
deepest point in the
ocean is equivalent to
1 person trying to
hold 50 jumbo jets
•
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The ocean constantly interacts with the atmosphere, exchanging
heat, moisture, and carbon dioxide (CO2)
The air-sea interaction drives our weather
Fast Fact:
patterns and influences the slowly
71% of Earth’s
occurring but dramatic changes in
surface is
our climate
covered by
oceans
hytoplankton
Fast Fact:
On a favorable day,
phytoplankton
concentration may
increase by as much
as 300%
 Microscopic, single-celled marine plants that
need water, CO2, sunlight, and chemical nutrients to grow
 Phytoplankton use a pigment called chlorophyll to capture sunlight during
photosynthesis
•
They decrease the amount of sunlight that reaches deeper water
• Confines oceanic heating to a small layer
 Why are phytoplankton important?
•
•
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Approximately half of the oxygen we breathe
is produced by phytoplankton
They take in CO2 from the atmosphere at the
same rate as land plants
All marine life is dependent upon the quantity
of phytoplankton available
http://www.gma.org/onlocation/globecactiv.html
Extension of Phytoplankton
 Currents can usually be traced by their supply of phytoplankton
 Scientists use satellites to remotely observe chlorophyll, which is contained in the
phytoplankton
• The images tell them:
• How much phytoplankton is present in the ocean
• Where they are located
• How much work they are performing
• How their populations are changing
 On Earth, humans can observe the phytoplankton
Fast Fact:
present in lakes and oceans
On a favorable day,
• Chlorophyll absorbs blue and red light
and reflects green light
• A water source that appears green in
color most likely contains some phytoplankton
20,000 specimens of
phytoplankton may be
3
contained in 1 ft of
ocean water
uikSCAT
 A satellite NASA uses to create an
image of the surface winds on Earth
 The QuikSCAT satellite carries a
SeaWinds scatterometer
•
A scatterometer is a microwave radar
that can measure near-surface wind
speed and direction over the ocean
under any weather conditions
 Why are scatterometers useful?
•
http://science.hq.nasa.gov/
They are giving meteorologists:
• More accurate measurements of
the winds associated with storms
• Advanced warning of high waves
and flooding
ain
http://lennthompson.typepad.com/lenndevours/miscellaneous_sips/index.html
 Precipitation that falls from clouds toward Earth’s surface
 Rain is an important part of the climate
•
The latent heat released into the atmosphere upon the formation of raindrops is a
significant form of energy that drives circulation in the atmosphere
 Why do meteorologists, oceanographers, and climate scientists find it important
to measure rainfall patterns?
•
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Scientists suspect that after rainfall the layers of fresh water at the
surface of the ocean affect circulation in the ocean
Rainfall appears to calm the seas
• Scientists question impact of rainfall on ocean damping
Did you know?
Falling drops of
rain are not tearshaped
Extension of Rain
 Drizzle – water droplets with a diameter less than 0.5 millimeters (mm)
 Rain – water droplets with a diameter greater than or equal to 0.5 mm
 The diameter of a raindrop that reaches Earth’s surface is usually no greater
than 6 mm
Diameter
 The shape of a raindrop is dependent on its size:
• Almost spherical – raindrops less than 2 mm in diameter
• Surface tension squeezes the drop into a sphere because
spheres have the smallest surface area for their total volume
• Flattened bottom, rounded top – raindrops with diameters bigger than 2 mm
• Larger air pressure on the drop as it falls, flattens the bottom, while lower
air pressure on the sides of the drop allows the sides to expand
1
ea Spray
Sea Spray
 There are two types:
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Film or jet droplets – bubbles in the ocean
rise to the surface and burst, releasing
water droplets into the air
Spume droplets – the wind is strong
enough to tear off water particles from the
tops of waves

Fast Fact:
Sea salt particles
make up 90% of the
marine aerosols in the
Atmospheric
Boundary Layer
http://www.pdphoto.org/
How does sea spray impact the earth?
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Once sea spray becomes airborne, the particles scatter radiation and
transfer heat, momentum, and moisture to and from the atmosphere
If the sea spray evaporates entirely, sea salt particles
are left in the air
• The particles act as nuclei for clouds and fog to form
• They impact Earth’s annual heat budget
Extension of Sea Spray
 1000 micrometers = 1 millimeter
 The radius of a circle:
Radius
1 millimeter
OR
1000 micrometers
http://science.nhmccd.edu/biol/dropdrag/superimposed.htm
 Radius of film or jet droplets: ranges from approximately 1 to 10
micrometers
 Radius of spume droplets: ranges from approximately 10 to 1000
micrometers
Low Tide
Gravitational
ides
Pull
H
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H
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T
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T
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Low Tide
 The regular rise and fall of the ocean waters
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Caused by the gravitational pull of the Moon and Sun, and the rotation of Earth
The rising of Earth’s surface is called high tide, or flood tide
The centrifugal force away from the moon leaves the water on the side opposite to the
Moon to form another high tide
Low tides, or ebb tides, are the portions of the tidal cycle between high tides
Did you know?
Tides do not
actually “rise”,
rather Earth rotates
into tides
 What impacts the time tides occur each day?
• The combination of Earth’s rotation and the Moon’s orbit
• If the Moon did not rotate around Earth, the tides would
occur at the same time every day
Extension of Tides
 The rise and fall of the tides is periodic
• Periodic – occurring in regular cycles
 There are three types of tides:
• Semidiurnal Tides:
• Produce two high tides and two low
tides during a 24 hour period (1 day)
• Diurnal Tides:
• Produce one high tide and one low
tide during a 24 hour period (1 day)
• Mixed Tides:
• Produce two high tides and two low
tides during a 24 hour period (1 day)
• There are great differences between the
heights of the high tides and the low tides
 To the right are tide curves for the three
common types of tides
• Curves show tidal patterns during a 48 hour
period (2 days) at various locations around
North America
4
pwelling
 Vertical movement of water from
the ocean floor up to the surface
 Coastal Upwelling - occurs when winds blow with the shore on the left
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Surface water is pushed away from the beach and deep, nutrient-rich, cold ocean
water rises in its place
 Coastal Downwelling - when winds blow with the shore on the right
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Surface water is pushed toward the beach, forced downward, and then out to sea
Coastal Upwelling and Downwelling in the Northern Hemisphere
Wind out of the North
Upwelling
Wind out of the South
Downwelling
 Northern Hemisphere: ocean water moves 90° to right of wind
 Southern Hemisphere: ocean water moves 90° to left of wind
ector Wind Stress
 The horizontal force per area
of wind on the ocean surface
 Vector wind stress impacts:
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Generation of waves
Movement of surface
currents
 How does vector wind stress
impact air-sea interaction?
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Through wind stress the
atmosphere is able to
transfer momentum to the
ocean
http://www.pfeg.noaa.gov/products/las/sample_gifs.html
aves
 As wind passes over the water, friction between
the air and the water causes the water to ripple
 Characteristics of waves:
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Period – time for two crests or troughs to pass a
point
Wave frequency – number of waves that pass a
point in one second
Did you know?
A wave does not
move water, only
energy moves
forward
 What determines the size of waves?
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How fast the wind is blowing
How far the wind blows
How long the wind blows
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Extension of Waves

As a wave passes, water particles lift up, move
forward with the wave’s crest, and then sink down
and move backward with the wave’s trough
 When water particles in the trough hit the sand,
friction causes them to slow down, but the water
particles in the crest do not slow down
 When the water in the crest gets too far ahead
for the trough to be able to support it, a breaker
forms, which is a wave where the crest crashes
on top of the trough
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Heat Flu
 The passing of heat through
or across a surface
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The mean annual radiation and heat balance of Earth
The heat flux within shallow
layers is much greater than
within deep layers of the
ocean
 Example of the importance
of heat flux to Earth:
• Earth must maintain an
annual balance between the
amount of heat absorbed by
its surface and released
back into the atmosphere
-2
W m (watts per square meter) is the unit used to represent
the power per square area that comes from the sun
16
Oceanograph
 Scientific study and exploration of the oceans
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Dependent on physics, chemistry, biology, geology, and meteorology
Covers a wide range of topics:
• currents, waves, tides, marine organisms, ocean floor, etc.
 Oceanographers must be able to apply knowledge from various branches of
study to truly understand and be able to explain the behavior of the ocean
environment
 Is there more than one type of oceanography?
http://www.capemalta.net/ma
ltapageOP/operocean.html
• Yes
• Biological oceanography (Marine biology) – study of marine
plants and animals
• Chemical oceanography – study of the chemistry of the ocean
and ocean floor
• Geological oceanography – study of the ocean floor
• Physical oceanography – study of ocean processes and air-sea
interactions
Krill
ooplankton
http://www.mar-eco.no/learning-zone/__data/page/93/Krill3.jpg
 Micro- or macroscopic animals that drift in the ocean
 Zooplankton can live at any ocean depth
 In comparison to any other animal, zooplankton have the greatest quantity
spread over the largest area
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Typically found near large quantities of phytoplankton
Concentrated in areas of upwelling
 Why are zooplankton important?
• They are a stable source of food
for many larger animals
http://www.gma.org/onlocation/globecactiv.html
References
1. Ahrens, C. D. (2005). Essentials of Meteorology: An Invitation to the Atmosphere (4th ed.).
California: Thomson.
2. Feldman, J. C. Ocean Planet: Oceanographic Facts. Smithsonian Institution. Retrieved July
13, 2007, fromhttp://seawifs.gsfc.nasa.gov/OCEAN_PLANET/HTML/education_
oceanographic_facts.html
3. Greely, T. (1998, Fall). Lesson 1: Why are the Oceans Important? Project Oceanography.
Retrieved July 13, 2007, from http://www.marine.usf.edu/pjocean/packets/
4. Groves, D. (1989). The Oceans: A Book of Questions and Answers. New York: John Wiley
& Sons, Inc.
5. Herring, D. Ocean & Climate: Physical Coupling with the Atmosphere. NASA. Retrieved
June 7, 2007, from http://earthobservatory.nasa.gov/Library/OceanClimate/oceanatmos_phys.html.
6. Hutchinson, S. & Hawkins, L. E. (2005). Oceans: A Visual Guide. New York: Firefly Books.
7. Kawasaki, K. (2006, September 5). Mapping the Oceans. NASA. Retrieved June 7, 2007,
from http://sealevel.jpl.nasa.gov/education/jason-game/game-mapping-oceans.pdf
8. Kawasaki, K. (2006, September 5). See How Winds Drive Ocean Currents. NASA.
Retrieved June 7, 2007, from http://sealevel.jpl.nasa.gov/education/jasongame/game-activity2.pdf
9. Looking at the Sea: Physical Features of the Ocean. (1998). Science Learning Network.
Retrieved June 7, 2007, from http://www.mos.org/oceans/planet/features.html
10. Looking at the Sea: The Water Cycle. (1998). Science Learning Network. Retrieved June
7, 2007, from http://www.mos.org/oceans/planet/cycle.html
Extension of References
11. Mueller, J. A. & Veron, F. (2006). A LaGrangian Turbulent Transport Model of Evolving
Sea-Spray Droplets over the Ocean. AMS: 14th Conference on Interaction of the
Sea and Atmosphere. (Vol. P4.3)
12. Niller, P. (1993). Gulf Stream. In The World Book Encyclopedia (Vol. 8, pp. 462-463).
Chicago: World Book, Inc.
13. Nystuen, J. (2000, June 14). Listening to Raindrops: Using Underwater Microphones to
Measure Ocean Rainfall. NASA. Retrieved June 7, 2007, from
http://earthobservatory.nasa.gov/Study/Rain/
14. Ocean in Motion. (2004, April 7). Office of Naval Research. Retrieved June 8, 2007,
from http://www.onr.navy.mil/focus/ocean/default.htm
15. Program 1: The Who? What? Where? How? And Why’s? of Plankton. (1997, Fall).
Project Oceanography. Retrieved July 13, 2007, from http://www.marine.usf.edu/
pjocean/packets/
16. Sample, S. (2005, June 21). Climate Variability. NASA. Retrieved June 8, 2007, from
http://science.hq.nasa.gov/oceans/system/climate.html
17. Sample, S. (2005, June 21). Sea Surface Temperature. NASA. Retrieved June 26,
2007, from http://science.hq.nasa.gov/oceans/physical/SST.html
18. Sample, S. (2005, June 21). The Water Cycle. NASA. Retrieved June 8, 2007, from
http://science.hq.nasa.gov/oceans/system/water.html
19. Stewart, R. H. (2005). An Introduction to Physical Oceanography. Texas: Texas A & M
University.
20. Stull, R.B. (1988). An Introduction to Boundary Layer Meteorology. In Atmospheric
Sciences Library (Vol. 13). Massachusetts: Kluwer Academic Publishers.
Extension of References
21. Tarbuck, E. J. & Lutgens, F. K. (2003). Earth Science (10th ed.). New Jersey: Pearson
Education.
22. The Living Sea. (1998). Science Learning Network. Retrieved June 7, 2007, from
http://www.mos.org/oceans/life/index.html
23. VanCleave, J. (1996). Oceans for Every Kid: Easy Activities that Make Learning
Science Fun. New York: John Wiley & Sons, Inc.
24. Water on the Move: Current Events. (1998). Science Learning Network. Retrieved June
7, 2007, from http://www.mos.org/oceans/motion/currents.html
25. Water on the Move: Wind and Waves. (1998). Science Learning Network. Retrieved
June 7, 2007, from http://www.mos.org/oceans/motion/wind.html
LEEANNE HAZZARD is a senior
at Elizabethtown College, where
she is working on her Secondary
Mathematics certification.
Leeanne created this ABC’s to
Oceanography booklet as part of
the Oceanography Outreach
Project she completed during a
REU Summer Internship.
Created by Leeanne Hazzard & Fabrice Veron, 2007
Air-Sea Interaction Laboratory
College of Marine and Earth Studies
University of Delaware