Ocean Currents Ocean Currents Surface currents Upper 400

Ocean Currents

Ocean Currents • Surface currents – Upper 400 m of the ocean (10%) • Deep water currents – Thermohaline currents (90%)

Surface Currents • Moves on or near the surface • Controlled by 3 factors: – Air currents (WINDS) – Earth’s rotation (CORIOLIS EFFECT) – Location of continents

Major Surface Currents • General Circulation – Currents travel from the Equator to the poles – Coriolis Effect causes currents to curve to the right (N hemisphere) – Creates clockwise GYRES (circulation patterns)

The Sargasso Sea • Calm, warm water • Pattern of winds and currents concentrates floating debris (garbage)

Deep Ocean Currents • Affected by 2 factors – Temperature • (Thermo-) – Salinity or saltiness • (-haline) • Deep water is cold, dense and salty • Surface water is warmer, less dense, less salty • Move more slowly than surface currents

Effects on Weather & Climate • Gulf Stream Current – Carries warm water from the equator to Northern Europe – Keeps Northern Europe much warmer than it normally would be

Effects on Weather & Climate • Humbolt (Peru) Current – Cold water upwelling towards South America – Keeps S. America cooler than it normally would be

Effects on Weather & Climate • Local Winds – Sea breeze blows from Sea to Land during the day – Land breeze blows from Land to Sea during the night – Due to water’s high heat capacity