1. Properties of Ocean Water
Chapter 24 Section 1

2. What does ocean water consist of?
Small particles of matter
Organisms
Dissolved substances

3. Dissolved Gases
The main gases in the atmosphere are nitrogen and oxygen.
The main gases in the ocean are also nitrogen and oxygen.

4. 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.

5. Gases enter the ocean from
Streams and rivers
Organisms
Volcanoes and
The atmosphere.
Most gases also return to the atmosphere from the oceans.

6. 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.

7. 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.

8. 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.

9. What changes salinity?
Precipitation adds fresh water & lowers salinity.
Evaporation removes water and raises salinity.
Salinity is highest in the Atlantic Ocean.

10. Temperature of Ocean Water
Water is warmed by the sun  warmer near equator.
Surface temperatures don’t change quickly.

11. Pack Ice
When ocean temperature falls to -1.9oC, the water freezes and forms pack ice that completely cover’s the ocean’s surface.

12. 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.

13. Density Temperature and salinity determine the density of ocean water.
Temperature affects density much more than salinity.

14. 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.

15. Color of Ocean Water Why is the ocean blue?
The water reflects blue light and absorbs other colors.

16. Plankton also adds color; when ocean life is disturbed, color can change.