Ocean Currents

Properties of the Ocean There is a layer in the ocean known as the thermocline. This is where the water temperature rapidly decreases with depth. In this layer cold water sinks rapidly.

Ocean as a Carbon Sink Oceans contain more than 60 times the carbon as the atmosphere. Dissolved CO2 may be trapped in the ocean for thousands of years. CO2 is absorbed naturally from the atmosphere.

Ocean Currents Current – a mass of water moving from one place to another. It is like a river within the ocean. They have a big influence on climate. http://www.youtube.com/watch?v=J_7c2y04FtA

Ocean Currents Two types of ocean currents: Surface Currents Deep Currents

Surface Currents Surface currents - a horizontal movement of ocean water caused by the wind and other factors. Occurs at or near the ocean’s surface. Controlled by wind, earth’s rotation and the location of the continents.

Surface Currents Wind causes friction between air and the ocean’s surface water – wind “pushes” the water.

Surface Currents Currents are forced to go around or travel along the edge of continents.

Surface Currents Earth’s Rotation causes the Coriolis Effect. Northern hemisphere deflects currents to the right - clockwise Southern hemisphere deflects currents to the left – counter clockwise

Deep Currents Deep currents – movement of ocean water far below the surface. Move slower than surface currents do.

Deep Currents What sets these deep currents in motion? Differences in densities of water due to Temperature Salinity

Duckies!

Deep Currents Salinity – a measure of the amount of dissolved salt in seawater. Factors that change salinity include: Evaporation – salt is left behind when ocean water evaporates, therefore increasing the water’s salinity and density Because of high evaporation rates, tropical waters (near equator) have the highest salinity. Freezing – when water freezes salt is left behind also increasing the surrounding water’s salinity and density.

Ocean Currents Factors that change temperature: The amount of solar energy an area receives.

Density, Temperature and Salinity Density of Water Properties More dense (higher density) Cold water, salt water Less dense (lower density) Warm water, fresh water

Ocean Currents