ocean circulation – ch. 16 -...
TRANSCRIPT
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.