Ocean circulation Two types of ocean currents surface

Ocean circulation Two types of ocean currents: • surface currents • deep ocean circulation

Surface Waters Circulate Horizontally, Pushed By Surface Winds Of Hadley, Ferrel, Polar Cells Called gyres

The Gulf Stream flows north, pushed by the trade winds of the tropics, warming the SE coast Florida Gulf Stream N W E S

The California Current flows south, pushed by the Westerlies, keeping the western Pacific ocean cool Florida Gulf Stream N W E S

Surface Currents = Gyres • 5 Gyres exist • 1 Cycle takes ~ 10 yrs • Caused by winds • Turned by Continents, Coriolis

The center of gyres have become giant whirling collections of garbage • All 5 gyres • Pacific’s is huge!

Breaks into small pieces Animals ingest it 6 x more plastic than plankton

Deep Water Circulation Coldest, saltiest water at Arctic sinks • A continuous deep current slowly drains one ocean into another • All the water is turned over in the process Antarctica recharges cold water

Recall: Angle of Solar Radiation Heats Earth’s Surface Unequally Sunlight Modified image from Windows to the Universe, http: //www. windows. ucar. edu

Ocean Surface Temperature is Varied as a Result 10 Radiation affects temp, density, evaporation Cold, dense; sinking water oceanworld. tamu. edu

Salinity is Another Factor the amount of salt dissolved in water evaporation, freezing act to increase salinity rain, runoff, & thawing of ice decrease salinity Higher salt = greater density

Factors influencing seawater density

All these density differences creates the Great Ocean Conveyor Belt Takes 1000 years for a complete cycle

Normal El Nino http: //esminfo. prenhall. com/s cience/geoanimations/animat ions/26_Nino. Nina. html

Warmer than normal : El Nino Colder than normal : La Nina Oceans temps measured via buoys

El Nino affects local weather, westerlies (jet stream), fisheries