The Conveyer Belt EEn Ocean circulation travels from the Atlantic Ocean through the Indian & Pacific oceans & back again Warm water in upper layers of ocean flows toward poles When water reaches the poles, temp drops & salinity increases, making it more dense. It returns to the equator as cold, deep water, eventual upwelling completes the circuit Moves around the globe influencing global climate by converting warm water to cold water & releasing heat to the atmosphere 2.3.1Explain ocean currents develop and move1 Density Currents: Density Currents: Vertical currents of ocean water result from density differences among water masses. Denser water sinks & slowly spreads out Causes by decrease in temperature An increase in salinity Evaporation Formation of sea ice A decrease in salinity Precipitation Runoff from land Icebergs melting Sea ice melting 2.3.1Explain ocean currents develop and move2 This cross section of Atlantic Ocean shows the deep-water circulation of water masses formed by density currents deep-ocean density currents begins in high latitudes at the surface When this water becomes dense, it sinks, initiating deep-ocean density currents Oceanographers can track the movements of density currents in the deep ocean by the temp, salinity, density of water mass & can map the slow circulation of water mass through the ocean Ocean Density & Currents 2.3.1Explain ocean currents develop and move3 Ocean Surface Currents Ocean circulation is organized into five major gyres, or circular current systems. North Pacific Gyre South Pacific Gyre North Atlantic Gyre South Atlantic Gyre Indian Ocean Gyre Factors Influencing Surface Currents Wind Coriolis effect deflection due to Earths rotation ( Rt. In the NH; Lt. in the SH) 2.3.1Explain ocean currents develop and move4 Ocean Currents and Climate Color satellite image shows temperatures in the Gulf Stream Warm water of the Gulf shown in red/orange Colder water shown in green, blue, and purple When currents from low-latitude regions move into higher latitudes, they transfer heat from warmer to colder areas on Earth As cold water currents travel toward the equator, they help moderate the warm temperatures of adjacent land areas ayer/view/assetGuid/9F61F275- AD4C-4FBF-9E00-8CA51F884A4Bayer/view/assetGuid/9F61F275- AD4C-4FBF-9E00-8CA51F884A4Bayer/view/assetGuid/9F61F275- AD4C-4FBF-9E00-8CA51F884A4B 2.3.1Explain ocean currents develop and move5