Ocean Circulation – Ch. 16 -...

OceanCirculation–Ch.16.1

AgEarthScience–Chapter15.2

oceancurrent

∗Massofoceanwaterthatflowsfromoneplacetoanother

surfacecurrent

∗Movementofwaterthatflowshorizontallyintheupperpartoftheocean’ssurface

gyre

∗Alargecircularsurfacecurrentpatternfoundineachocean

Corioliseffect

∗Theapparentdeflectiveforceofearth’srotationonallfree‐movingobjects,includingtheatmosphereandoceans;DeflectionistotherightintheNorthernHemisphereandtotheleftintheSouthernHemisphere.

upwelling

∗Therisingofcoldwaterfromdeeperlayerstoreplacewarmersurfacewaterthathasbeenmoved.

densitycurrent

∗Currentofoceanwaterthatresultsfromdensitydifferencesamongwatermasses

DamConcrete

SurfaceCirculation

∗ OceanCurrents–massesofoceanwaterthatflowfromoneplacetoanother.

∗ SurfaceCurrents–movementsofwaterthatflowhorizontallyintheupperpartoftheocean’ssurface.

∗ Surfacecurrentsdevelopfromfrictionbetweentheoceanandthewindthatblowsacrossitssurface.

SurfaceCirculation

∗ Gyres–Hugecircular‐movingcurrentsystemsthatdominatethesurfacesoftheoceans

∗ CoriolisEffect–thedeflectionofcurrentsawayfromtheiroriginalcourseasaresultoftheEarth’srotation.

∗ Becauseoftheearth’srotation,currentsaredeflectedtorightintheNorthernHemisphereandtotheleftintheSouthernHemisphere.

SurfaceCirculation

∗ Whencurrentsfromlow‐latituderegionsmoveintohigher‐latitudes,theytransferheatfromwarmertocoolerareasofEarth.

∗ Ascoldwatercurrentstraveltowardtheequator,theyhelpmoderatethewarmtemperaturesofadjacentlandareas.

SurfaceCirculation

∗ Upwelling–therisingofcoldwaterfromdeeperlayerstoreplacewarmersurfacewater.

∗ Upwellingbringsgreaterconcentrationsofdissolvednutrients,suchasnitratesandphosphates,totheoceansurface.

Deep‐OceanCirculation

∗ DensityCurrents–verticalcurrentsofwaterthatresultfromdensitydifferencesamongwatermasses.

∗ Cold,saltywaterismoredensethanwarmerwater,soitdropsdownverticallyintothedepthsoftheoceanandisreplacedbylessdensewater.

∗ Evaporationofoceanwaterinwarmsurfaceareasalsocanincreasesalinity(density)andcausesthedenserwatertodropandbereplacedbylessdensewater.