Hydrosphere

*Remember, about 97% of all the water on Earth is ocean water and not readily available for people to use.

Visit: http://www.csduroy.qc.ca/EileenGermain/oceans_and_seas/

*The ocean is salty because of dissolved chemicals eroded from the Earth’s crust and washed into the sea:

*Solids and gases come from volcanoes.

*Particles are dropped into the oceans by winds.

*Materials from sediments are deposited on the ocean floor.

*These things combine with the ocean water to dissolve (because remember water is the universal solvent) and mix with the other particles in the ocean water.

*Salinity (the amount of salt in water) increases through evaporation or freezing of ocean waters.

*Salinity decreases when rainfall, runoff, or ice melts and adds water to the ocean.

*The average salinity of ocean water is 35 ppm.

*ppm stands for parts per million

*Salinity levels are much less in coastal water, polar seas (Arctic Ocean), and where rivers empty into the oceans or seas.

*There are many gases dissolved in the ocean.

*The major gases are nitrogen, oxygen, and carbon dioxide.

*Some of these gases, as you saw on the previous slide, come from sediments and volcanoes.

*Other organisms also contribute to the dissolved gases:*Marine plants release oxygen and take in carbon dioxide

(same as a plant on land) when it goes through photosynthesis.

*Marine animals need oxygen and release carbon dioxide to go through cell respiration (same as land animals).

*Cold water and deeper waters hold more gas than warm and shallow waters.

*As the atmospheric gas levels rise, so do the levels of the same gases dissolved in the ocean water.

*Some carbon dioxide stays a gas.

*Other carbon dioxide reacts with

*the ocean water to form carbonic acid

*carbonates already in the water to form bicarbonates

*Bicarbonates removed CO2 from the water.

*Marine organisms use the bicarbonate to form calcium carbonate shells.

*When these organisms die, some of the bicarbonate is returned to the water, but a lot if settles down to the sea bed.

http://science.nasa.gov/earth-science/oceanography/ocean-earth-system

*The ocean can hold and circulate a lot of water, heat and carbon dioxide throughout the Earth (more than the atmosphere).

*Remember the water cycle: water is constantly being recycled and transferred to different parts of the Earth.

*The ocean and atmosphere work together to form complex weather patterns:*North Atlantic Oscillation

*El Nino

*The ocean and atmosphere also interact chemically:*Radiation released into our environment

http://www.srh.noaa.gov/ama/?n=elnino

http://www.newx-forecasts.com/nao.html

*Also remember specific heat of water is very high, so that means water takes a long time to heat up, but once there, it takes a long time to cool off.

*This keeps the air above the ocean warm. When the ocean is warm it can affect the climate up to 3 months beyond the season and keeps the seasons milder than on continents.

*This means the warmth from summer heats up the ocean and can last until the end of fall.

*Air temperatures all over the world are circulated and regulated by the heat of the oceans.

*Heat from the ocean can be stored in the upper two hundred meters of the photic zone.

*The photic zone is a specific amount of water where there is sufficient light for photosynthesis to occur.

*The ocean will store and release heat based on the temperature of the water.

*Evaporation cools ocean water which cools the atmosphere. This is easiest to see near the equator and hard to observe near the polar regions because of the extreme temperatures.