Deep Ocean Circulation http: //nssdc. gsfc. nasa. gov/planetary/image/earth_day. jpg 1
Effect of Solar Radiation on Sea Surface Temperature Sunlight Modified image from Windows to the Universe, http: //www. windows. ucar. edu 2
Sea Surface Temperature oceanworld. tamu. edu 3
Surface Currents Sea to Air Heat Transfer 4
Deep Ocean Currents Driven by Density of Seawater hawaiianphotos. net melindawebster. com What effects water density? • Colder water Denser (to 4°C) • Saltier water Denser 5
Deep water forms when: http: //oceanexplorer. noaa. gov/ ● Surface water flows to the poles and gets colder ● When seawater freezes it leaves salt behind, increasing salinity ● Water becomes denser and sinks 6
Modeling cold salty water sinking 7
Global Conveyor Belt Sinking Cold, Salty Water 8
Courtesy NASA/JPL-Caltech http: //sealevel. jpl. nasa. gov/index. html 9
Global Conveyor Belt Thermohaline Circulation – Thermo = temperature – Haline = salinity 10
Why is thermohaline circulation important? • Major influence on climate • Transfers heat from equator to poles • Nutrient cycling • Brings oxygen to deep ocean organisms 11
O 2 Warmed and lit by sun PRODUCED in surface ocean Mixed with atmosphere (oxygen) Mixed Surface Ocean Boundary Deep Ocean O 2 Photosynthesis O 2 Less Nutrients Cold, Dark, No Photosynthesis, More Nutrients Oxygen (O 2) USED O 2 12
How will global climate change affect thermohaline circulation? • Melting of sea ice • Increased precipitation informify. com ØDecrease in salinity ØMay alter thermohaline circulation 13