The document discusses several key physical properties of ocean water. It notes that ocean water exists in three states of matter and has a high heat capacity that regulates climate. Its unique hydrogen bonding allows it to dissolve many substances. Salinity varies latitudinally and affects water density, leading to stratification into layers. Light penetration and sound transmission are affected by these physical factors. The hydrologic cycle and global conveyor circulation distribute ocean waters globally.

1. Characteristics of Ocean Water

2. • Oceanography covers physical properties
of the ocean:
–Dissolved materials: minerals and salts
(salinity) and gases
–Properties that change with depth: light,
temperature and pressure
–Motion: Waves, tides, currents

3. Waters Unique Properties…
-Found in 3 states of matter on our
planet
-High heat capacity: ability of water
to hold heat energy and regulate our
climate
-Universal solvent: can dissolve
more things than any other solvent

4. Unique Properties of water are due to
Hydrogen Bonding-
attraction between water molecules because
of the unequal charges of O & H
• Charges on O and H help it dissolve things
like salts
• Attraction between water molecules- a lot
of heat is needed to increase water temp
and when water cools it release a lot of heat

5. Water is recycled from the ocean to the land and returned
to the sea.
• The reservoirs of water include:
– Oceans - cover 60% of the northern hemisphere
and 80% of the southern hemisphere and
contains 97% of Earth’s water.
– Rivers, lakes and glaciers.
– Groundwater - contains a larger volume of water
than all of the water in lakes and rivers.
• The hydrologic cycle describes the exchange
of water between ocean, land and
atmosphere.
5-7The Ocean as a Physical System

6. 5-7
The Hydrological cycle

7. Resource cycling
within the ocean

8. Salinity displays a latitudinal relationship
related to precipitation and evaporation.
• Highest ocean salinity is between 20-30o north and south
or the equator.
• Low salinity at the equator and poleward of 30o results
because evaporation decreases and precipitation
increases.
• In some places surface water and deep water are
separated by a halocline, a zone of rapid change in
salinity.
• Water stratification (layering) within the ocean is more
pronounced between 40oN and 40oS.
5-5 Chemical and Physical Structure of the
Oceans

9. Latitudinal variation in salinity

10. Salinity Profiles

11. Density of sea water is a function of
temperature, salinity and pressure.
• Density increases as
temperature decreases and
salinity increases as pressure
increases.
• Pressure increases regularly
with depth, but temperature and
salinity are more variable.
• Higher salinity water can rest
5-5
Chemical and Physical Structure of the
Oceans

12. Density Stratification

13. The water column in the ocean can be divided into
the surface layer, pycnocline and deep layer.
• The surface layer is about 100m thick,
comprises about 2% of the ocean volume
and is the most variable part of the ocean
because it is in contact with the atmosphere.
• The surface layer is less dense because of lower
salinity or higher temperature.
• The pycnocline is transitional between the
surface and deep layers and comprises 18%
5-5
Chemical and Physical Structure of the
Oceans

14. Factors leading to a pycnocline

15. Density Structure of the Ocean

16. Salinity
• Result of weathering of rocks on
land carried by rivers to the
ocean
• Materials from the earth’s
interior
– Hydrothermal vents
– Volcanic eruptions

17. Materials in Seawater
–Oceans have an average salinity
of 3.5% or 35 ppt (35 ‰)
– ppt= parts per thousand
–More than 70 elements in
seawater but the main ones are..

18. Chloride
Sodium
Sulphate
Magnesium
Calcium
Potassium

20. An overview of Ocean Stratification

21. • Tropical and subtropical oceans are permanently
layered with warm, less dense surface water
separated from the cold, dense deep water by
a thermocline, a layer in which water
temperature and density change rapidly.
• Temperate regions have a seasonal thermocline and
polar regions have none.
5-5Chemical and Physical Structure of the
Oceans

22. Dissolved Gases
• Oxygen, carbon dioxide and nitrogen
• Dissolve into the ocean from the
atmosphere through wave action
• Dissolve better in cold water
• Animal life can change the chemistry
of ocean gases

23. • Around 500 m water runs out of
oxygen
–Bacteria and other animals are
using it during decomposition and
respiration
• Animals in this region and lower have
large gills, modified hemoglobin
or are inactive

25. Pressure
• We are under 1
atmosphere (atm) of
pressure on land
• Water is heavier than
air so every 10 m deep
= 1 more atm of
pressure

26. Animal Adaptations and Pressure
• Ocean life has adapted to deep ocean
and 1000x our pressure with
lightweight skeletons, little
musculature, and reduced metabolic,
growth and reproductive rates.
• Diving mammals have rib cages that
collapse and expand in result to
changing pressure

27. Water Depth vs Light
• Photosynthetic organisms use light to
make sugars.
• Sunlit area (top 100 meters) contains 90%
of marine life
• Colors of penetrate thru water differently
–Red light filters out first and blue light
goes the furthest
–Red animals are essentially invisible in
deep waters

28. • 65% of light entering the ocean is
absorbed within the first meter and
converted into heat. Only 1% of light
entering the ocean reaches 100m.
• Water displays the selective absorption of
light with long wavelengths absorbed first
and short wavelengths absorbed last.
• In the open ocean, blue light penetrates
the deepest.
The Ocean Sciences: Other Physical
Properties of Water

29. Light Absorption, open
ocean

30. • In turbid coastal waters light rarely
penetrates deeper than 20m. and the water
appears yellow to green because particles
reflect these wavelengths.
• The photic zone is the part of the water
column penetrated by sunlight.
• The aphotic zone is the part of the water
column below light penetration and
The Ocean Sciences: Other Physical
Properties of Water

31. Light absorption in nearshore, productive water

33. The speed of sound in water increases as salinity, temperature and pressure
increase, but in the ocean, the speed of sound is mainly a function of temperature
and pressure.
• Above the pycnocline increasing pressure
with depth increases the speed of sound
despite the gradual decrease in temperature.
• Within the pycnocline, the speed of sound
decreases rapidly because of the rapid
decrease in temperature and only slight
increase in pressure.
The Ocean Sciences: Other Physical
Properties of Water

34. Behavior of sound in water

35. • SOFAR Channel is located where
sound speed is at a minimum.
Refraction of sound waves within the
channel prevents dispersion of the
sound energy and sound waves travel
for 1000s of kilometers within the
channel.
The Ocean Sciences: Other Physical
Properties of Water

36. The sea surface microlayer is the water surface to a depth of a few hundred
micrometers. It is critical for the exchange between the atmosphere and the ocean.
• Neuston layer is the habitat of the sea surface microlayer and is inhabited by the
neuston, all organisms of the microlayer.
• Processes that transport matter to the surface layer from below are:
– Diffusion - random movement of molecules.
– Convection - vertical circulation resulting in the transfer of heat and matter.
– Bubbles - the most important process because bubbles absorb material and inject it into the air
as they bursts.
• Processes within the microlayer can be divided into the:
– Biological - bacteria and plankton are much more abundant in the layer than below.
– Photochemical effect - the interaction of ultraviolet light and organic compounds.
The Ocean Sciences: Sea Surface
Microlayer

37. The sea-surface microlayer

38. Summary of
resource cycling

40. Energy in the Ocean
• Ocean takes
longer to heat
and cool than
land due to its
specific heat
• Water temp
decreases with
depth

41. Animal Adaptations and Temperature
• Colder temps reduce the metabolic rate
• In very cold waters fish have a special
protein like antifreeze to keep tissues
from freezing
• Lighter colored animals stay cooler than
darker colored animals and are found in
warmer waters
• Some marine life have thick layers of fat
to insulate their bodies

42. Motion in the Ocean…Tides
• Daily rise and fall of the ocean (high
and low tide)
• Range as small as 1 m & as high as
20m
• Some areas have 1 or 2 high & low
tides
• Caused by gravitational pull of moon
on our ocean basin

43. TIDES
•Tides rise (FLOOD) to produce a
HIGH TIDE
• And fall (EBB) (LOW TIDE)
Moon/
Sun

44. This side is pulled towards the
Sun and/or Moon by
gravitational attraction
This side bulges out because
of inertia
Therefore, there are two high tides on Earth at
any one time

45. Marine Life and Tides
• Some marine life time their
reproduction to the high or low tide
cycle
• Horseshoe crabs come ashore to
mate on the night of a high tide in
May
• Eggs hatch 2 wks later on a high tide
and are washed into the ocean

46. Motion in the Ocean…Waves
• Winds produce waves as it blows
across the ocean’s surface
• When waves enter shallow water they
drag along the ocean floor
• The wave top is moving faster than
the wave bottom so it topples forward
• Specialty waves: rogue waves, tidal
waves and tsunamis

47. At the shoreline

48. • Surf -
sequence of
breaking waves
• Swash - water
sliding up
beach
• Backwash -
water flowing
back down
beach to sea

49. Longshore drift
• Waves arrive at a
coast at an angle
(swash)
• Backwash returns
at 90 degrees
Sand is moved along the beach = longshore
drift or longshore current

50. Coastal
deposition
• Result of
longshore drift
and a lot of
sediment
• produces
extensions of
deposit from
the shoreline

51. • May grow
across a bay
(baymouth
bar)
• May link an
island to the
main land
(tombolo)
spit = curved extension

52. Motion in the Ocean-Currents
• Rivers of water moving through
the ocean
• Surface currents caused by major
wind belts
• Deflected by the Coriolis Effect
• Important in moving marine life
and nutrients around the oceans

54. Vertical Ocean Currents
• Differences in temperature and salinity
change the density of water.
• This causes sinking and rising of water in
the ocean
• Ocean conveyor belt- convection current
of water moving between the equator and
poles in the oceans
• Takes 1600 years to cycle