1Marine BiologyMARS 3450, Fall 2013Instructor: Tim HollibaughOffice: 248 Marine SciencesEmail: [email protected]: 542-7671Grading: Quizes 20%, Midterms (2) 20%, Homework 10%, Final 30%Syllabus is posted on eLCLectures will be posted on eLCThe Physical & Chemical EnvironmentMARS 3450 Fall 2013Lecture 1Physical and Geological Oceanography•Oceans are 71% of Earth’s Surface•Four major ocean basins:•Many minor basins: Mediterranean, Caribbean, Baltic, etc.BasinArea (million km2)Average depth (m)Pacific 166 4,188Atlantic 87 3,736Indian 74 3,872Arctic 10 1,330Castro and Huber 2003The “Southern Ocean” Major basins are connected in the southern hemisphereOcean BathymetryOcean DomainsNote mountains, ridges and valleysGlobal ChlorophyllWhat causes the patterns?How do they affect other organisms, processes?Northern Winter Northern SummerWater: A special substanceOcean ChemistryImportant properties of water• Thermal properties: o High heat capacityo High latent heat of vaporization• Mechanical propertieso Surface tensiono Viscosity• DensityOcean ChemistrySeawaterOcean ChemistryIn 1 Liter L or 1 kilogram kg of seawaterMost elements are NOT evenly distributed through the water column12Dissolved GasesOcean ChemistryO2Dissolved OxygenOcean Chemistry15Oxygen distribution in the ocean at ~200 m depthCarbon DioxideOcean ChemistryCarbon Dioxide & pHCO2 + H2OH2CO3H++ HCO3‐2H++ CO32‐Remove CO2, decrease H+, increase pHAdd CO2, increase H+, decrease pHSeawater slightly alkaline: pH 7.5‐8.4Ocean ChemistryOcean ChemistryAtmospheric CO2 is Increasing19Density:Controls the vertical structure of the oceanDensity is a function of: water salinity, water temperatureand (to some extent) pressure (depth)20More salt makes water denserVolume doesn’t change (much) when salt is added, so adding salt increases the mass per unit volumeSalty sea water is denser than less salty seawater, sinks beneath it(temperature being equal)Ocean SalinityOcean Chemistry22Warm water is less dense than cold waterthereforeCold water sinks beneath warm water(salinity being equal)Ocean TemperaturesOcean PropertiesOcean PropertiesWater TemperatureNot UniformOcean PropertiesOcean Water MassesTemperature SalinityZ = 1000 mOcean MovementThe ocean has a liquid “geography” very much like the landThese habitats are as different as mountains and swamps to the organisms that live in themOcean MovementThese patterns are globally coherent, influenced by local inputs of water or saltSurface CurrentsOcean MovementCastro and Huber 2003Water Movements in the OceanSurface water:WindTradesWesterliesEasterlies1.CoriolisThe Coriolis Effect• Depends on you seeing things while standing on the rotating Earth•Consequence of inertia, not a real force•Deflection to RIGHT in N•Deflection to LEFT in S•No deflection at EquatorOcean MovementOcean MovementThe “Ekman Spiral” is a consequence of the “CoriolisForce” and friction between water layersNet transport of the surface layer is at 45oangle to the direction of wind forcingOcean MovementThere is a coherence between currents and patterns. Why?Ocean MovementWhat happens when the wind blows from south to north?Northern HemisphereOcean MovementWater Movements in the OceanDeep water:DensitySalinityTemperature(Wind, Coriolis Effect = only top 100 m)Add salt to freshwater:increases salinityincreases densityAdd heat to water:increases temperaturedecreases densitySumich 1992Deep water circulation patternsWater sinks at poles•Total Circulation time = ~1000 years•Surface and deep waters are not isolated from one anotherThe Ocean Conveyor BeltThe SmithsonianOcean MovementTidesOcean MovementCastro and Huber 2003Tides: 1 lunar cycle takes 26 days, therefore high tide advances by 1 h each dayActual tide is influenced by bathymetry,
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