1. Characteristics of the Ocean Beth Roland Eighth Grade Science Team 5 Mountaineers

2. Chemical Composition of Ocean Water

3. Dissolved Gases Nitrogen(N 2 ), Oxygen (O 2 ), and Carbon Dioxide (CO 2 ) are the main gases dissolved in ocean water. Temperature has an important impact on the amount of gases that are able to be dissolved in our oceans: –The lower the temperature the more gas molecules that can dissolve –The higher the temperature, the less gas molecules that can dissolve

4. Ocean Salinity Salinity is the measurement of the amount of dissolved solids in a given amount of liquid. Ocean water consists mainly of the dissolved salt, sodium chloride NaCl also known as common table salt. On average, ocean water consists of 3.5% of dissolved solids but this value varies based on climate in a given ocean or sea

5. Changes in Salinity Climate has a significant impact on an oceans salinity: –Coastal water near areas with hot, dry climates have higher salinity due to an increase in evaporation (leaving more dissolved solids in the water) –Coastal water near areas with cool, humid areas have lower salinity due to a decrease in evaporation Additionally, slow moving bodies of water have higher salinity because there is a decrease in fresh water inflow

6. Temperature Zones in the Ocean Surface Zone- warm, top layer that extends 300 m below sea level. Sunlight can penetrate and warm cooler water below Thermocline- extends to 700 m and here temperature drops significantly with depth Deep Zone- extends to the bottom of the ocean (1200 m) temperature ranges from 1 o C to 3 o C

7. Current Ocean Temperatures

8. Surface Temperature Changes The further away from the Earth’s equator, the less direct the sun’s rays and the cooler the temperature Additionally, when the Earth is tilted away from the sun (fall and winter) the rays are even less direct than during our spring and summer months.

9. A Global Thermometer! Water has the ability to absorb and hold heat energy from the sun’s radiation. –Water absorbs heat energy slower than dry land but can maintain the heat energy for longer periods of time. Ex. Night swimming Currents that circulate water carry warmer water to areas that are cooler and thus carry heat energy to different parts of the world. Ex. The gulf stream carrying warm water travels to the British Isles and the water temperatures are significantly warmer than locations at the same latitude