Ocean Water

1
Ocean Water

• Water, water everywhere and all the boards did
  shrink,
• Water, water everywhere and not a drop to drink.

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Water

• Dihydrogen Monoxide (H2O)
• Pure
• Tasteless
• Odorless
• Colorless

3
So whats in the Ocean???

• Smells
• Doesnt taste good
• Brown, green, yellow, dirty mucky gross
• Suspended plants and animals
• Complex mixture of chemicals that sustain a
  variety of plant and animal life

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Two parts

• Dissolved gases
• Dissolved solids

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Dissolved Gases

• Two main gases in the atmosphere
• ________ and __________
• Same two are present in the ocean water

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Also

• Carbon Dioxide
• While not a main atmospheric gas it makes up a
  large part of ocean water.
• Other!
• Small amounts of other atmospheric gases present
  in ocean water

7
Hows it get there??

• Enter from water in streams and rivers
• Underwater Volcanic eruptions
• Living organisms in the ocean
• Plants make oxygen as product of photosynthesis
• Most oxygen enters from surface of ocean

8
Temperature and dissolved gas

• Temperature affects amount of gas that can be
  dissolved in water
• Gas dissolves more readily in cold water than
  warm water
• Flat soda
• Tropical water, warmer Icy water colder
• Which one has more dissolved gas??

9
Returns to atmosphere

• If water temperature rises, gas will escape
• There are higher levels of CO2 in the atmosphere
  at the equator, why??

10
Oceans regulate climate

• Contain more than 60 times as much carbon as the
  atmosphere
• Holds on to that carbon dioxide forever!!
• CO2 major contributor to trapping heat
• Greenhouse effect etc.
• Traps energy from sun

11
2nd Part Dissolved Solids

• Ocean water is 96.5 pure H2O
• Other 3.5 is made up of dissolved sollids called
  sea salts

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Sea Salts

• 6 Most abundant sea salts
• Sodium
• Chlorine
• Magnesium
• Sulfur
• Calcium
• Potassium
• Two most abundant, sodium 30.6, Chlorine 55.0
• Form NaCl (sodium chloride) halite

13
Sources

• Three main sources
• volcanic eruptions
• weathering and erosion
• chemical reactions between seawater and new sea
  floor
• Rivers carry about 400 BILLION kilograms of
  dissolved solids into the ocean (mostly salt)

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Salinity

• Salinity- a measure of the amount of dissolved
  salts in a given amount of liquid
• Main difference between salt water and freshwater
• Measured in parts per 1000 or (insert funny
  looking percent sign here)

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Example

• If a 1000 gram sample of ocean water contained 35
  grams of solids what would the salinity be??
• About 35 parts per 1000 or 3.5

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• Freshwater is less than .1 salt.

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Factors that change salinity

• Evaporation
• Temperature rises
• Water evaporates
• Salt stays behind
• Areas where surface temp is greater have higher
  salinity levels

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• Depth
• The deeper it is the colder it is
• The colder it is the less evaporation there is
• The less evaporation the smaller salt to water
  ratio
• Overall the amount of salt is due to temperature
  changes

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Salinity Ranges

• From below 33 ppt to above 36 ppt
• Average salinity of 34.7 ppt
• Can vary by location
• Mediterranean sea has high levels
• Red Sea has more than 40 ppt. (dry hot climate,
  causes lots of evaporation)

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Temperature of Ocean water

• Varies upon
• Depth
• Location
• Affected directly by the amount of solar energy
  an area receives AND
• by movement of water

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Surface water

• Heat distributed downward from 100 to 300 m
• Relatively constant temperature
• Very slight temp decrease as depth increases
• DOES decrease temp as latitude increases
• Which is warmer, polar water or equatorial
  water??? (water at poles or equator)

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Tropical surface water

• Quite frequently reaches temperatures of 30 C (86
  F)
• Receives large amounts of solar energy year round

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Polar surface water

• Usually drop below -2 C (28.4 F)
• Ocean water freezes at -2 C
• Large sheets of ice form
• Floating
• Covers large area
• Usually about 5 m thick
• Pack ice- a floating layer of sea ice that
  completely covers an area of the ocean surface

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Middle latitudes surface water

• Ranges in temperature depending on season (amount
  of sun)
• May vary as much as 10 C in some areas
• Usually about 10-20 C (50-70 F)

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Thermocline
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Thermocline

• Sun cannot heat ocean water below the surface
  layer
• Temp decreases sharply (more rapidly than other
  layers)
• Levels out at deep water
• Marks distinct separation with warm surface and
  cold deep water

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Factors affecting thermocline

• Currents
• Shifting water could alter the depth of the
  thermocline
• Seasons
• Sometimes the thermocline disappears depending on
  what time of the month it is

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Deep ocean water

• Usually about 2 C
• Colder the water denser the water
• Denser further down
• Density of the water controls slow deep ocean
  currents
• Dense cool polar water sinks and flows towards
  warm equator
• Holds more gas than surface water

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DENSITY

• What does density mean?

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Density

• Density- The ratio of the mass of a substance to
  the volume of the substance
• Ex. 1cm3 of pure water has a mass of 1 g so the
  density of pure water is 1g/1cm3
• Different liquids have different densities

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Density and Ocean water

• Two factors affect density
• Temperature
• Salinity
• Dissolved solids add mass to the water which
  change the density
• When the mass increases the density increases
• Ocean waters density is between 1.026g/cm3 and
  1.028g/cm3

32
Temperature again

• The main factor in density differences is the
  water temperature
• Water gets more dense as it becomes colder
• Water near the poles (cold) sinks and moves
  through ocean basins near the floor