物理海洋Review.

Review•TheshapeandsizeoftheearthPear-shaped;averageradius(6371km);rotationrate(7.3×10-5s-1);L(1°)↔111.13km;L(1′)↔1.852km;1nauticalmile(海里)=1.852km;1kts(节）=1nauticalmile/hour=0.51m/s•DistributionofOceanandLandLandandwaterarenotuniformlydistributedonthesurfaceoftheearth–Ocean70.8%,Land29.2%–Nearlyallofthewaterontheplanet(approximately98%)iseitheroceanwaterorseaice.–About70%ofthelandmassesarelocatedintheNorthernHemisphere.TheSouthernHemisphereisprimarilycoveredwithwater–Thereisonlyonebandoflatitudeontheglobeinwhichthereismorelandthanwater.Thisoccursbetween45°Nand70°N–Thehypsographiccurveshowsthatroughly80%ofthelandsurfaceisbelowanelevationof2000meters,while80%oftheseafloorisatadepthgreaterthan2000meters.–Smallchangesinsealevelcanhavealargeeffectontherelativesurfaceareasoflandandwater.•OceanandSea–FourPrincipleOcean–Hydrologicalfeaturesofocean,sea,fjord(bay),strait(channel)•Latitude&Longitude•ChartProjectionChartsandmapsareusedtoshowtheearth’sthree-dimensionalsurfaceonaflat,ortwo-dimensional,surface.–Anychartormapresultsinsomeamountofdistortionoftheearth’struesurface.Thetrickistochoosethetypeofmapthatgivestheleastdistortionforthespecificpurposeyouhaveinmind.–Mapsaremadebyprojectingthefeaturesoftheearthontosometypeofsurface,generallyeitheracylinder,acone,oraplanetangenttothesurfaceoftheearthatsomepoint.CalculatedistancebetweentwoLatitude/Longitudepoints•HaversineFormula•AnotherSimpleonePoint1(lon1,lat1)Point2(lon2,lat2)[degree]Y=(lat2-lat1)*111.13(km)X=(lon2-lon1)*cos((lat2+lat1)/2)*111.13(km)Distance=sqrt(x*x+y*y)(km)LongitudeandTimeInternationaldatelineReview•Propertiesofpurewater•Salinity(S)andConductivity(电导率)•Temperature(T,℃)•Density(,kg/m3)–s,t,p=density–1000(insitudensity,现场密度)–s,t,0(t,条件密度)Shorthandmethodofexpressingthedensityofasampleofseawateratatmosphericpressureasdeterminedbyitsinsitutemperatureandsalinity–α(specificvolume,比容)：α=1/ρ(m3·kg-1)S,T(SpecificVolumeAnomaly,热比容偏差）S,T=α(S,t,0)-α(35,0,0)S,T=-95.1t+2675(accurateto1inS,T,t=23to28)q(potentialdensity)(位密):isthedensityaparcelofwaterwouldhaveifitwereraisedadiabaticallytothesurfacewithoutchangeinsalinity.q(s,q,0)Whentakingintoaccountoftheadiabaticcompressionwithincreaseofdepth,thewaterisnotunstablebutisinneutralequilibriumbelow6450m.Effectofpressureondensity•Pressurehasrelativelylittleeffectondensitycomparedtosalinityandtemperature,however,thedensitywillincreasewithincreasingpressure(ordepth)andbecomesimportantinthedeepseawheresalinityandtemperatureremainnearlyconstant.T=0C&S=35p=0,s,t,0(t)=28.13p=4000,s,t,4000=48.49EffectofsalinityandtemperatureondensityExpansionandcontraction,orchangeinvolumeofonegramofwaterwithchangesintemperature.At0℃waterexpandsduringchangeofstatetoice.Between0℃and4℃watercontractsasitwarmsandexpandsasitcools.Above4℃waterexpandsasitwarmsandcontractsasitcools.TheeffectofSalinity•S24.7,thedensitywillincreasewithdecreasingtemperatureuntilitreachesamaximumvalueandwillthendecreaseuntilthewaterfreezes-justaspurewaterbehaves.•S24.7,thedensitywillcontinuetoincreasewithdecreasingtemperatureuntilthewaterfreezesT↓，↑T↓,↓•Table4.4–WhenSisconstantandgreaterthan24.7,thedensitydecreasesasTincreases–WhenTisconstant,thedensityincreaseswithincreasingSTNoSaltSalt20253035-1Ice0.9171.016061.020101.024131.0281700.999841.016071.020081.024101.0281310.999901.016051.020051.024061.0280720.999941.016031.020011.024001.0279930.999961.015981.019951.023931.0279140.999971.015931.019881.023841.0278150.999961.015861.019801.023741.02770100.999701.015321.019801.023081.02697150.999101.014501.018321.022151.02599200.998201.013421.017201.020981.02478250.997041.012101.015851.019601.02336300.995651.010571.014281.018011.02175AsSalinityincreasesdensityincreases.AsTemperatureincreasesdensitydecreasesReview•Effectofpressure,temperatureandsalinityondensity–Densityincreasewithincreasingpressure(depth)[relativelittle]–S24.7,thedensitywillincreasewithdecreasingtemperatureuntilitreachesamaximumvalueandwillthendecreaseuntilthewaterfreezes-justaspurewaterbehaves–S24.7,thedensitywillcontinuetoincreasewithdecreasingtemperatureuntilthewaterfreezes–WhenTisconstant,thedensityincreaseswithincreasingSAsSalinityincreasesdensityincreases.AsTemperatureincreasesdensitydecreasesOfthefourdiagramsshown,onlyoneshowsthecorrectdensitydependenceontemperatureandsalinity.Whichoneisit?？()abcdyouaregivenfourwatersamplesA,B,CandDwiththetemperaturesandsalinitiesshownintheTS-diagram.Whichofthelistedarrangementsofwatersamplesgive(s)astablestratification?a)BACDb)ABCDd)BCADe)DACB•Theoceanicheatbudget–MajortermsandequationQSW—InsolationQLW—NetInfraredRadiationQS—SensibleHeatFluxQL—LatentHeatFluxQV—AdvectionQT—totalheatgainorloss–Zonaldistributionoftheheatbudgetterms•TheoceanwaterbudgetERPq–Therelationshipbetweensalinityand(E-P)Salinitydisplaysalatitudinalrelationshiprelatedtoprecipitationandevaporation.•Highestoceansalinityisbetween20-30onorthandsouth•Lowsalinityattheequatorandpolewardof30oresultsbecauseevaporationdecreasesandprecipitationincreases.Annualmeantemperatureattheseasurfac