Ocean Water Chemistry and Currents

Ocean Water Chemistry

• Salinity: the amount of salt dissolved in ocean water– 1kg of ocean water contains 35g of salt.– Ocean contains many different kinds of salts

Differences in Salinity

• Lower salinity near the surface because of rain, rivers, etc.

• Hot climates cause evaporation which makes water saltier (ex. Red Sea)

• Saltier near the poles (salt is left behind when water freezes)

Temperature of Ocean Water

• Temperatures vary with location

• Temperature is warmer near the surface

**Temperature drops and pressure increases as you go deeper underwater!!

Cold Water

Warm Water

Cold Water

Warm Water

Cold Water

Currents• Currents are a “river” of water within the

ocean

• There are two types of currents:1. Surface Currents 2. Deep Currents

Surface Currents

• Ex. Gulf stream

• Several hundred meters deep

• Warm surface currents can effect climate by warming or cooling the air above it.

• Influenced by the coriolus effect– Move clockwise in the northern hemisphere– Move counter clockwise in the southern

hemisphere.

Surface Currents move horizontally!!

Surface Currents

Deep Currents

• Caused by differences in density

• Cold water rises as it is heated, warm water sinks as it cools

• Salty water sinks, less salty water rises

Warm Water and Less Salty Water

Cold Water and More Salty Water

Deep currents move vertically!!

El Nino

• Occurs every 2-7 years

• Winds form over the western Pacific

• Warm water moves east.