Patterns of Circulation in the Ocean Topic 4

Patterns of Circulation in the Ocean Topic 4 Lesson 3

Surface Currents • Ocean water moves as waves and as currents • Currents carry water from one place to another • Surface currents – move water at the surface of the ocean • Driven by global winds • Follow Earth’s global wind patterns (Flow in circular patterns) • Gulfstream – largest and most powerful

Factors Affecting Surface Currents • Global wind belts • Unequal heating of Earth • Rotation of Earth • Coriolis effect • N. Hemisphere curve to the right • S. Hemisphere curve to the left

Effects on Climate • Gulfstream redistributes heat from equator to poles • Climate is the temperature and precipitation of an area over a long period of time

• El Niño and La Niña • Makes winds along the equator weaken and reverse direction (West to East) • Can last for 1 or 2 years • Increases rainfall and snowfall • La Niña • • Strong winds More water to move west Cold water rises Creates colder winters and more precipitation

Deep Ocean Currents • Caused by differences in density • Affected by the Coriolis Effect (they curve) • Dense water = cold and salty • SINKS • Flow slowly from poles to equator

The Global Ocean Conveyor • Loop of ocean current • Circulates oxygen and nutrients • Starts cold in the North Atlantic Ocean

The Global Ocean Conveyor