8. Salinity of Ocean Water salinity a measure of the amount of dissolved salts in a given amount of liquid Ocean vs. Freshwater = amount of salt Salinity is measured by the number of grams of dissolved solids in 1,000 g of ocean water.

9. Factors that Change Salinity rate of evaporation Higher = more salt, lower = less salt Tropical waters have a higher salinity at the surface than polar waters do. Why do you think that is? Salinity also decreases as depth increases. Salinity of the ocean’s surface ranges from 33‰ to 36‰.

10. Factors that Change Salinity, continued High Low

11. Temperature of Ocean Water ocean temperature varies depending on depth and location on the surface of the oceans Affected by the amount of solar energy an area receives and by the movement of water in the ocean geographyalltheway.com

12. Surface Water The mixing of the ocean’s surface water distributes heat downward to a depth of 100 to 300 m. The temperature of surface water does decrease as latitude increases. Therefore, polar surface waters are much cooler than the surface waters in the Tropics. pack ice a floating layer of sea ice that completely covers an area of the ocean surface no more than 5 m thick, because it prevents the water below from freezing

13. The Thermocline a layer in a body of water in which water temperature drops with increased depth faster than it does in other layers Marks a distinct separation between the warm surface water and the cold surface water

14. marinebio.org nasaimages.org

15. Deep Water Temperature is usually about 2°C Cold water is denser The density controls the slow movement of the deep ocean currents Holds more dissolved gases

16. Density of Ocean Water  density the ratio of the mass of a substance to the volume of the substance  Mass/Volume  expressed as grams per cubic centimeter for solids and liquids and as grams per liter for gases  Two factor that affect density of ocean water: salinity and temperature  Dissolved solids add mass to ocean water, which makes it denser than pure fresh water

17. Density of Ocean Water Continue  Colder ocean water get = denser, the warmer it get = less dense  Temperature affect density more than salinity  Densest ocean water is found in the polar regions, because surface temperatures are the coldest.

18.  The color of ocean water is determined by the way it absorbs or reflects sunlight.  As the sunlight enters the surface of the ocean the blue wavelengths are reflected back making the ocean water appear to be blue. Color of Ocean Water

19.  Organisms, such as phytoplankton, can affect the color of the water.  Phytoplankton absorb red and blue light, but reflect green light.  What color would the ocean appear to be?  Phytoplankton require nutrients, thus the presence or absence of phytoplankton can indicate the health of the ocean. Why is Ocean Color Important