Download Properties of Ocean Water

Properties of Ocean Water
Chapter 24 Section 1
What does ocean water consist of?
 Water
 Small particles of matter
 Organisms
 Dissolved substances
Dissolved Gases
 The main gases in the
atmosphere are nitrogen
and oxygen.
 The main gases in the
ocean are also nitrogen
and oxygen.
Gases dissolve better in cold
liquids.
 Gas molecules can fly
away more easily at
higher temperatures.
 As temperatures
change, the
atmosphere and the
ocean are always
exchanging gases.
Gases enter the ocean from




Streams and rivers
Organisms
Volcanoes and
The atmosphere.
 Most gases also return to
the atmosphere from the
oceans.
Carbon Dioxide
 The ocean contains sixty
times more carbon
dioxide than the
atmosphere.
 It is a carbon sink.
 When carbon dioxide
dissolves in water, the
water becomes acidic.
More CO2 means more
acidic.
Dissolved Solids
 The most abundant
elements in ocean water
are Na, Cl, Mg, C, S & K.
 There are also trace
elements, found in very
small amounts.
 85% of the ocean’s
dissolved solid is sodium
chloride (NaCl), salt.
Salinity
 The amount of dissolved solids in a liquid is called
salinity.
 When water evaporates from the ocean, it leaves salt
behind.
 3.3 to 3.6% of the ocean is salt.
What changes salinity?
 Precipitation
adds fresh water
& lowers salinity.
 Evaporation
removes water
and raises
salinity.
 Salinity is highest
in the Atlantic
Ocean.
Temperature of Ocean Water
 Water is warmed by the sun  warmer near equator.
 Surface temperatures don’t change quickly.
Pack Ice
 When ocean
temperature falls to 1.9oC, the water
freezes and forms
pack ice that
completely cover’s
the ocean’s surface.
Thermocline
 There’s a point where
water temperature
decreases SHARPLY with
depth.
 The temperature drops as
much as 20oC to 2oC
 This is the border
between surface water
and deep water.
Density
 Temperature and salinity
determine the density of
ocean water.
 Temperature affects
density much more than
salinity.
Density
 Water near the surface is warmer and less dense, so it
doesn’t mix easily with deeper water.
 Deep ocean currents form when cold polar water sinks and
moves below the warm water to the equator.
Color of Ocean Water
 Why is the ocean blue?
 The water reflects blue
light and absorbs other
colors.
Plankton also adds color; when
ocean life is disturbed, color can
change.