Current and Climate Ch 13-4

Which is more dense? Hot water is red and cold water is blue. Is cold water more dense than warm water? How can you tell? Explain.

Current A large stream of moving water that flows through the oceans Can carry water from one place to another Because of the density differences between warm and cold water some currents form on the surface of the ocean and others form deep in the ocean

Surface Currents Are driven mainly by winds. Most flow east to west and then double back to complete the circle

Coriolis Effect Because the Earth is moving on its axis this motion effects the elements of the Earth that can freely move

Coriolis Effect In the Northern Hemisphere the currents curve to the right In the Southern Hemisphere the currents curve to the left The Coriolis effect is strongest at the poles and weakest at the equator.

Gulf Stream Most powerful surface current in the North Atlantic Ocean Carries warm water from the Gulf of Mexico up the North American coast

Gulf Stream This powerful current brings warm water up from the tropics to northern countries like Norway The heat exchange with the air allows northern points to experience milder climatic conditions despite the geography Video

Effects on Climate Currents carry warm and cold water around the Earth As heat is transferred from the water to the air (warm currents) or from the air to the water (cold currents) The exchange of heat effects the weather patterns

El Nino El Nino, an abnormal warming of surface ocean waters in the eastern tropical Pacific Scientists do not fully understand Can affect the ocean as well as the land Causes a shift in the weather patterns around the world such as a unusually warm winter in the Northeastern USA

Deep Currents Caused by the differences in density of ocean water Warm water moves from the Equator to the Poles It gradually cools Ice forms The ice is fresh water The remaining water has increased salinity The water becomes dense and sinks The deep currents carry cold, dense, highly salinated water from the Poles to the Equator

Upwelling The movement of cold water upward from the deep ocean and now begins the shift to a warm current The winds blow away warm water and cold water replaces it Brings up nutrients from the deep ocean

Oceans in Motion Safari Montage