Download Oceanography Notes- Ocean Water Properties and

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Oceanography Notes- Ocean Water Properties/ Currents
Name ______________
Date ____________
Vocabulary
On a separate sheet of paper define each term in a complete sentence and number. Those terms
that are * please illustrate
Overturn
Thermohaline Circulation*
Convergence
Tropical convergence
North Atlantic deep water*
Antarctic bottom water*
South Atlantic surface water*
Divergence
Ekman spiral
Gyre
Eddy*
Downwelling*
Upwelling*
Calories
Heat capacity
Density*
Conduction*
Convection*
Radiation*
Refraction*
Sonar*
Sofar Channel
Salinity*
Trace element
Nutrient
Desalinization
Reverse osmosis
PH*
Ekman Transport
Ocean Water Properties
A. The Water Molecule
1. Made up of three atoms: two __________and one __________, arranged at a ____________ angle
2. Each hydrogen atom has a ___________ while oxygen has a _____________ which attracts with other
water molecules and creates a weak bond
B. Changes of State
1. Water when subjected to low enough temperatures solidifies to become ice, when exposed to high
enough temperatures water will vaporize into ________________
2. A calorie is the amount of heat needed to raise the temperature of 1 gram of water 1 degree Celsius
a. The larger the amount of water the more calories are required to raise all of the water’s temperature
___________________
b. The ______________ is the amount of heat required to raise the temperature of 1 gram of water 1
degree Celsius, the high heat capacity of water allows it to gain and lose heat without changing
_______________________
c. Salt water has changes the temperature of freezing water to ____________ and boiling water to
above 100 Celsius
C. Density
1. Defines as ______________________, measured in ___________________________
2. Temperature and Salinity affect water density
a. Temperature- as water temperature lowers to 4 degrees Celsius, its density _______________, once
below 4 degrees Celsius its density begins to _______ until it becomes ice at 0 degrees Celsius
1) Molecules of water are placed closer together with decrease in temperature until
__________________ then the molecules are starting to arrange themselves into a solid and are
more spread out
b. Salinity- density of water increases when salt is added because salt has a greater density than water,
so __________________ at approximately –1 degree Celsius is the densest
D. Transmission of Heat
1. Heat energy is transferred through water in 3 ways
a. _____________- heat is applied in one location and passes to other water molecules, water is a poor
conductor, metals are excellent conductors
b. ________________- heat is applied from below and by density circulates to the top while cooler,
more dense water falls to the bottom to be heated
c. _____________- heat is directly applied from its source such as the Sun’s energy warms ocean
water
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E. Transmission of Light
1. 80% of sunlight is absorbed within the first 10 meters of seawater, no sunlight passes
_____________________
2. The color of oceans is affected by the amount of ________________________ in the seawater, the open
ocean appears clear and _________ because there is no suspended matter while coastal water appear
_______________________ due to silt from rivers and microscopic organisms
F. Transmission of Sound
1. The speed of sound in water is _____________ than in air (water- 1500 meters per second vs. air- 334
m/s), temperature, pressure and salinity when increased, ______________the speed of sound in seawater
2. Echo sounders send sound waves to the sea bottom to determine depth and even sea floor structure is
temperature, pressure and salinity are known
3. Sonar (sound navigation and ranging) can determine echoes in water and distinguish between
_______________________________________________
G. Dissolving Ability of Water
1. The ability of water molecules to separate compounds into their ions makes water an excellent
__________, when sodium chloride is placed in water its bonds break and ions form which attach to
water molecules
H. Salts in Seawater
1. Salinity is measured in g/kg or ____________________, 86% of salt ions are _________ and
______________, other ions are magnesium, calcium, potassium, and sulfate
2. Trace elements in seawater area less than 1 part per million
I. Determining Salinity
1. The first way is by adding ______________ to a sample which reacts with the most salt ions (this
method is sometimes called Chlorinity)
2. The second method is easier by using a __________________ which measures the electrical
conductivity of seawater, the more conductive the water, the greater the salinity
J. Ocean Salinities
1. Ocean salinity is usually ______________________, evaporation increases ocean salinity while
precipitation decreases salinity
2. Depending on _________________ salinity varies based on the climates of rainy belts or desert belts
3. Where rivers empty into the ocean can lower salinity to 25 ppt, in landlocked salty water such as the
______________ salinity can be as high as 42 ppt
K. The Salt Balance
1. Salt comes from a variety of sources: river discharge (from erosion of sediments), volcanoes and midocean ridges
2. Researchers believe that salt composition has not changed in ________________, so there is a balance
of removal of salinity by being absorbed by organisms or ___________________
L. Nutrients and Organics
1. Nitrate, phosphate and silicate are three nutrients presented in low concentrations that are considered
fertilizers of the ocean for _______________________
M. The Gases in Seawater
1. ______________________________________ are the most abundant gases in seawater, interaction
with the atmosphere is how most of the gas is found in the oceans but biologic activity influences CO2
and oxygen levels
N. Carbon Dioxide as a Buffer
1. CO2 acts as a buffer to seawater changing its pH, (_______________________), from an acid or basic
solution, average ocean pH is about ________
O. Salt and Water
1. By evaporation of isolated seawater, ________ of the world’s salt is extracted
2. Desalination is a process to obtain freshwater from seawater, the drawback is the
____________________ needed to abstract freshwater
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Currents
A. Density Driven Circulation
1. To increase density of water, there must be a _____________________ or an increase in salinity
2. Warm tropical seawater is the least dense while ____________________ tends to be the densest
B. Thermohaline Circulation
1. The vertical circulation by surface changes in temperature and salinity is called
_________________________
a. ____________- water with a high salinity or low temperature (both are more dense) tends to fall to
the bottom of the ocean and rise up in another location at a different latitude
b. ________________-If a surface process forms more dense water on top, water table becomes
unstable and denser water sinks
c. __________- less dense water rises
d. _______________________ controls thermohaline circulation, changes in temperature are more
important than changes in salinity= climate is getting warmer!!!
C. The Layered Oceans
1. The Atlantic Ocean has a dramatic source of deep water coming from Antarctica and the North Atlantic
that circulates to the equator, seawater is assigned names based on their point of origin which usually
has a certain ________________________
2. The Pacific and Indian Oceans deep seawater circulation is sluggish due to topography (very little Arctic
waters in the Pacific and none for Indian) and location
For D, E, and F refer to pages 186-191 of Chapter 7,
D. Winds on a Non-Rotating Earth
1. As water circulates in the ocean due to _____________ so does air in the atmosphere
2. Wind is produced by the _____________________of air due to density differences
3. Warm air (like warm water) rises at the ______________ and moves towards the poles in a large
_____________________ (see figure 7.15, page 187)
4. Winds are named for the direction from which they blow
E. The Effects of Rotation
1. Due to the ______________ of the Earth air moving in the convection cell mentioned above is deflected
2. The deflection of the moving air in relation to the moving surface due to rotation is called the
_______________________
a. All objects above the Earth’s surface are deflected due to this effect, if a plane leaves near the
Equator and travels directly north then it will gradually be __________________
b. A plane flies directly ______________ then it will be deflected west
F. The Wind Bands
1. Due to the Coriolis effect the air that rises at the equator and moves north (shifted east) and south
(shifted west), the air then sinks or rises depending on density (affected by temperature and water
vapor), causing a _______________________ (page 191)
a. ____________- surface winds between 30 degrees North or South from west
b. _____________- between 30-60 degrees N,S surface winds blow from west
c. The ______________, at the equator, and the horse latitudes at 30 degrees N, S are areas that are
known to not have wind
G. Wind-Driven Water Motion
1. Wind driven currents are deflected to a _____________ from the direction of the wind due to the
Coriolis effect, creating a large scale circulation in the open oceans
2. Below the surface the deeper water down to 150 meters is deflected in the
____________________ection of the wind, called the _______________ after Swedish physicist
Walfrid Ekman in 1902
H. Current Flow and Gyres
1. In the Northern Hemisphere, circular currents called ________ travel in a clockwise pattern around the
ocean, in the Southern Hemisphere the gyres travels in a _________________________
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I.
J.
K.
L.
M.
a. Gyres are created due to ________________s of water at 30 degrees North and South causing a rise
in elevation of about a meter, water flows down the convergence and is then deflected by the
Coriolis effect causing circulation
b. On the western side of a northern ocean, the flow of water tends to ______________________, this
is caused by an increase in the Coriolis effect and stronger winds the further north
Ocean Surface Currents
1. Analyzing Currents
a. ________________- current that on western area of Atlantic that brings warm water to New Jersey
in the summers
b. _____________________- Gulf Stream water flows toward Europe in the N. Atlantic
c. _________________- brings cold water to Europe on the eastern side of the Atlantic
d. How would you describe the water in California?
e. How would the water off the coast of Peru be different in the southern hemisphere?
K. Convergence and Divergence
1. ________________________- surface water moves horizontally into a region where sinking occurs,
referred to as an area of downwelling
2. ____________- an area of rising water that has been displaced by sinking converging water, referred to
as an area of upwelling
3. seawater near the equator does not converge as deep as seawater _______________
4. Horizontal movement of seawater is much more rapid than ___________________of seawater
Coastal Upwelling and Downwelling
1. _______________- Ekman transport drives surface water toward or away from coast, bringing deep
nutrient rich water to the surface stimulating growth of marine plants
2. _______________- change in wind direction allowing colder water to sink to the bottom
__________________
1. Packets of warm water moving in a circular motion- Gulf Stream in the N. Atlantic
Measuring the Currents
1. Ways to measure currents:
a. Following a parcel of moving water
b. Measuring the speed and direction of water using buoys or dye
c. Satellite databases