Surface Currents Movement of water that flow in the upper part of the ocean’s surface

1. Caused by friction between the ocean and the wind that blows across its surface 2.Created by the prevailing wind system 3. Currents are closely related to the general circulation pattern of the atmosphere 4. Can be localized, seasonal or permanent

Gyres Huge moving current systems that dominate the surface of the oceans 5 main gyres North PacificSouth Atlantic South PacificNorth Atlantic Indian Ocean Four main currents within each Gyre

The major cause of gyres is… the Coriolis effect – the deflection of currents away from their original as a result of the Earth’s rotation Northern Hemisphere – deflection to the right Southern Hemisphere – deflection to the left

Currents and Climate Transfer of heat from areas of high temp to areas of low temp low latitude currents move to high latitudes – transferring heat from the warm to the cooler areas

The Gulf Stream brings warmer water to Great Britain and Northwestern Europe Causes warmer winters (felt in the middle latitudes)

Currents and Climate High latitude currents move to low latitudes – transferring cooler water to warmer climates

The Peru current brings cooler water north to the tropics Causes cooler summers

Ocean currents help maintain the Earth’s heat balance Ocean water movement accounts for ¼ of heat transport on the Earth

Upwelling The vertical rising of cooler water from deeper layers of the ocean to replace warmer surface water Wind induced

Coastal upwelling – occurs along the western coast of continents (N.A, S.A. and Africa) coastal winds and the Coriolis effect combine to move surface water away from the shore cooler water from below moves upward to replace warm water – results in cooler surface temperature cooler temperatures brings greater amounts of nutrients and therefore greater amount of fish and other marine life