海洋化学与生物海洋

MarineChemistryandBiologicalOceanography海洋化學與生物海洋Biologystartswithchemistry•Biologicalprocesses–thelevelsofelementsandcompounds•Abundanceofbiotaandtropicrelationship–chemicalparameters,salinity,dissolvedoxygenandnutrientGlobalwatercycleturnovertime•Theoceanhasaturnovertimeofabout37,000yearswithrespecttoriverinflow.Thisishowlongitwouldtaketofilltheoceanifitweretotallydry.•Turnovertimesaredefinedasthemassinthereservoirdividedbytheinputorremovalrate.Bycomparisontheaverageresidencetimeofwaterintheatmospherewithrespecttoevaporationfromtheoceansandcontinentsisonlyabout10days.ScopeofChemicalOceanography:FundamentalQuestions•-Whatarethechemicalcontrolsonbiologicalproductionandfoodwebstructureoftheocean?Insomeoceanareasironlimitsphytoplanktongrowth.•Martin(1991)conductedexperimentswhereheaddedirontosamplesandshowedthataddingironstimulatedgrowthrateandalsostimulateddiatomproduction.•Martin(1991)conductedexperimentswhereheaddedirontosamplesandshowedthataddingironstimulatedgrowthrateandalsostimulateddiatomproduction.-Inwhatwaysdobiologicalprocessescontrolthedistributionsofchemicalsintheocean?•Photosynthesisandrespirationcontrolthedistributionofmanyelementsinseawater.Compositionsofseawater•0.45mmfilter•Passed–•Cannotpass–•Humicacid,proteinandaminoacid,polysaccharide,pigments,inorganiccolloids(ironhydroxide)salinity•TotalamountofsaltsinwaterBioavailability•Canbeutilizedbycells-membrane•relatedtodissolvedmaterialsandparticulatematerials•Mostparticulatematerialscannotbeefficientlyutilizedbyphytoplanktonandalgae•理由:largesizeofparticulatematerials–cannotpassthroughcellmembraneorviathechannelSpeciationandglobalhydrologicalcycle7days3550daysGlobalhydrologicalcycleTime-dependenteventsDissolvedgases•Oxygen:dissolvedoxygen(DO)•Surface,temperature,biologicalutilizationandemission•2.0-10mg/Lintertidalregions•Verticaldistribution:50mnovariation•Photosynthesis(+O2)•Respiration(-O2)PrimaryproductivityCO2cycle•CO2(gas)↔CO2(dissolved)•H2O+CO2↔H2CO3•H2CO3↔H++HCO3-•HCO3-↔H++CO32-•Ca2++CO32-↔CaCO3(solid)•表示法:alkalinity(A)–thenumberofmolesofhydrogenionrequiredtoconvertallanionsofweakacidstotheirunionizedformin1kgofwaterpHandCO2CO2cycleCcycleNutrient•Phosphorus(P)•Nitrogen(N)•Co-variationofNandP•Refieldatomicratio:C:N:P=106:16:1(1934,1963)•N:Pratio30:1Plimitation•N:Pratio10:1Nlimitation•SiliconSpatialvariationsTemporalvariationsOrganiccarbon•DissolvedorganiccarbonDOC•ParticularorganiccarbonPOC•POCinphoticzoneisrecycledbymicro-organisms.