Modeling the spatial and temporal distribution of planktonic foraminifera [Elektronische Ressource] / vorgelegt von Igaratza Fraile Ugalde

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Modeling the Spatial and TemporalDistribution of PlanktonicForaminiferaDissertation zur Erlangung desDoktorgrades der Naturwissenschaftenam Fachbereich Geowissenschaftender Universitat¨ Bremenvorgelegt vonIgaratza Fraile UgaldeSeptember 2008The question is not what you look at, but what you see- Henry David Thoreau -iContentsAcknowledgements viiAbstract viii1 Introduction 11.1 Planktonic foraminifera .......................... 11.2 as paleoproxy .................. 61.2.1 Foraminiferal abundance as a paleotemperature proxy . . . . 71.2.2 shell chemistry as ae proxy . . 91.2.3 Difficulties associated with foraminifera-based proxies . . . . 101.3 Seasonality of planktonic foraminifera 111.4 Scientific objectives ............................. 132 A dynamic global model for planktonic foraminifera 252.1 Introduction . . ............................... 252.2 Model setup . . 272.2.1 Ecosystem model .......................... 272.2.2 PLAFOM . 272.2.3 Standard model experiment: grid, forcing and boundary con-ditions ................................ 332.2.4 Comparison to core-top data ................... 352.2.5 to sediment-trap data ................ 352.2.6 Sensitivity analysis of the parameters .............. 362.3 Results .................................... 382.3.1 Spatial distribution patterns.................... 382.3.2 Temporal .................. 41iiiContents2.3.3 Spatio-temporal distribution pattern ............... 452.3.

Sujets

• Biologie

Informations

• Publié par: universitat_bremen
• Publié le: 01 janvier 2008
• Nombre de lectures: 48
• Langue: English
• Poids de l'ouvrage: 6 Mo

Extrait

emporalT

and

Spatial

the

Modeling

Planktonic

of

Distribution

Foraminifera

September

2008

von

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Igaratza

Fraile

Ugalde

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at¨Universit

am

GeowissenschafteneichFachber

des

Erlangung

zur

Dissertation

NaturwissenschaftendergradesDoktor

The

question

is

i

not

what

you

look

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at,

but

Henry

what

David

you

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eauThor

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Acknowledgements

Abstract

Contents

Introduction1..........................foraminiferaPlanktonic1.11.2Planktonicforaminiferaaspaleoproxy..................
1.2.11.2.2ForaminiferalForaminiferalshellabundancechemistryasaasapaleotemperaturpaleotemperaturepreoxypr.oxy.....
1.2.3Difficultiesassociatedwithforaminifera-basedproxies....
1.3Seasonalityofplanktonicforaminifera..................
.............................objectivesScientific1.4

2Adynamicglobalmodelforplanktonicforaminifera
2.1Introduction.................................
2.2Modelsetup.................................
..........................modelEcosystem2.2.1..............................PLAFOM2.2.22.2.3Standardmodelexperiment:grid,forcingandboundarycon-
................................ditions2.2.4Comparisontocore-topdata...................
2.2.5Comparisontosediment-trapdata................
2.2.6Sensitivityanalysisoftheparameters..............
2.32.3.1ResultsSpatial....................................distributionpatterns....................
2.3.2Temporaldistributionpatterns..................

iii

vii

viii

11679101131

255272727233535363838314

Contents2.3.42.3.3SensitivitySpatio-temporalexperiment:distributionspatio-temporalpattern...............distributionpatterns45
withconstanttemperature.....................45
2.4Discussion..................................47
2.4.1Comparisonwithcore-topdata..................47
2.4.2Comparisonwithsediment-trapdata..............50
2.4.3Sensitivityanalysis.........................51
2.4.4Modelexperimentwithconstantmixed-layertemperature..51
2.5Summaryandconclusions.........................53
33.1SeasonalIntrbiasoductionin..Foraminifera-based...............................Proxyrecords6677
3.2DataandMethods.............................69
3.2.1Descriptionofthemodel......................69
3.2.2Sediment-trapdata.........................69
3.2.3Experimentaldesign........................71
17....................................Results3.33.3.1Influenceofseasonalityandtemperaturesensitivityontem-
peratureestimates.........................71
3.3.2Sensitivityanalysis.........................73
3.4Discussion..................................77
3.4.1Latitudinalspeciesdistribution..................77
3.4.2SensitivityofspeciestochangesinSST.............79
3.5Conclusions.................................80
4SeasonalityofplanktonicforaminiferaduringtheLastGlacialMaximum91
4.1Introduction.................................91
29...................................Methods4.24.2.1Foraminiferamodelandexperimentsetup...........92
4.2.2CCSM3ClimateModelsimulations...............93
4.2.3UVicEarthSystem-ClimateModelsimulations........95
4.2.4Sedimentaryfaunalassemblages.................97
4.2.5Flux-weightedtemperaturesignal................98
4.3Results....................................100
4.3.1RelativeabundancesofthespeciesduringtheLGM......100
4.3.2ForaminiferalseasonalityduringtheLGM...........102
4.44.4.1Discussion.Comparison..between...............................modeloutputandsedimentsamples..110404
4.4.2Influenceofseasonalityonproxyrecords............105
iv

Contents4.5Conclusions.................................109
5VerticaldistributionoflivingplanktonicforaminiferaintheAzoresFront119
5.1Introduction.................................119
5.2Materialandmethods...........................120
5.2.1Samplingandprocessing.....................120
5.2.2Oceanographicsetting.......................122
5.3Results....................................126
5.3.1Totalforaminiferalfauna.....................126
5.3.2Foraminiferalassemblagecomposition.............126
5.3.3Modelprediction..........................127
5.4Discussion..................................131
5.4.1Depthhabitatofthespecies....................131
5.4.2Comparisonbetweensamplesandmodelprediction.....132
5.5Conclusions.................................134
139Summary6141Conclusions77.1Outlook....................................142
AModelnotationandequations145
A.1A.2CouplingParametersforbetweentheecosystemforaminiferaandmodelforaminifera..................models........114465
A.2.1Variablesandinitialvalues....................146
A.2.3A.2.2SpeciesBiologicalspecificparametersbiologicalcommonparameterstoallspecies........................114476
A.3Modelequations...............................149
v

Acknowledgments

ThisworkwascarriedoutattheGeosciencesDepartmentofBremenUniversity,
andwasfundedbyDeutscheForschungsgemeinschaft(DFG)withintheEuropean
GraduateCollegue“ProxiesinEarthHistory”(EUROPROX).Theysupportedme
duringthreeyearsgivingtheopportunitytoparticipateinseveralinternationalcon-
ferencesandexchangeprograms.
IMulitza,wouldwhoseliketothoughtfulthanktomyadviseoftensupervisors,servedProf.togiveMichaelmeaSchulzsenseofanddirDr.ectionStephandur-
ingmyPhDstudies.Iwouldhavebeenlostwithoutthem.Thankyouforbelieving
inme,andforalwaysencouragingmetogobeyondmypastachievements.Ialso
liketoexpressmygratitudetoProf.MichalKucerawho,duringmystayinthe
UniversityofT¨ubingen,sharedwithmealotofhisexpertiseandresearchinsight.
IamindebtedtomymanycolleaguesandPhDstudentsatBremenUniversity
forprovidingastimulatingandfunenvironmentinwhichtolearnandgrow.Iam
especiallygratefultothe’palmod’group,whocreatedafriendlyworkingenviron-
ment.AndreasManschkewasparticularlyhelpfulincomputersupport,patiently
teachingmetoworkwithLinux.MathiasPrangehasbeenalwaysinterestedinmy
researchandIwouldliketothankhimforallhiscontributions.J¨orgFranke,who
spentplentyoftimefightingwithmycomputerproblemsandprovidedmeseveral
usefulpiecesofhiscode,turnedoutagreatofficemate.
IwishtothankeverybodywithwhomIhavesharedexperiencesinlife.From
thepeoplewhofirstpersuadedandgotmeinterestedinsciencetothosethathave
joinedmeinthediscoveryoflife.IwouldspeciallyliketothankCatalinaGonz´alez
andIlhamBoumetarhamwho,withthegiftoftheircompanyandunconditional
friendship,mademydaysinBremenmoreenjoyableandworthliving.
Finally,Iwouldliketothankmyfamilyfortheunderstanding.Theyhaveal-
wayssupportedandencouragedmetodomybestinallmattersoflife.TothemI
thesis.thisdedicate

vii

UgaldeFraileIgaratzaemenBrOctober200817,

Abstract

iments,Planktonicanddueforaminiferatotheircontributeexcellentprsubstantiallyeservationtointhesediments,fossilrecorthedoffossilmarineshellsarsed-e
ofnalgreatassemblagespaleoceanographicandgeochemicalsignificance.compositionTemporalofthevariationsindividualinfossilsedimentaryshellshavefau-
becomeimportantproxiesforpastoceanicconditions.Differentecologicalprefer-
encesbetweenspeciescausedistinctseasonalpatterns,andtheimprintofdiffering
seasonalproductionispreservedinthesedimentaryrecord.Accurateknowledgeof
foraminiferalecologyandseasonalsuccessionisindeedcrucialtocorrectlyinterpret
becorrsensitiveespondingtoprtemperaturoxy-basede,randeconstrtherefoructions.eclimatePlanktonicchangesmayforaminiferaalterartheeknownseasonalto
patternofspecies.Anychangeinthetimingofthelargestfluxtotheseafloorthat
mayhaveoccurredinthepastwillleadtoabiasinestimatedpaleotemperature.
Therefore,thisdissertationfocusesonthevariabilityofplanktonicforaminiferal
seasonalitythroughtime,anddiscussesitsimplicationsforpaleotemperaturere-
uctions.constr

Anumericalmodelsimulatingthepopulationdynamicsofplanktonicforamini-
ferawasdevelopedandcoupledtoanexistingmarineecosystemmodel.Thismodel
isforcedwithaglobalhydrographicdataset(e.g.,temperature,mixedlayerdepth)
andwithbiologicalinformationtakenfromtheecosystemmodeltopredictmonthly
concentrationofthefollowingforaminiferaspecies:Neogloboquadrinapachyderma
(dextralandsinistralvarieties),Globigerinabulloides,Globigerinoidesruber(whiteva-
riety)andGlobigerinoidessacculifer.Thesespeciesaresensitivetosea-surfacetemper-
ature,andduetotheirhighspatialcoverageandabundancearethemostcommon
planktonicforaminiferaspeciesusedinpaleoceanography.Themodelresultsfor
theglobaldistributionofplanktonicforaminiferaformodernconditionsarecom-
paredtoavailablecore-topandsediment-trapdata.IntheNorthAtlantic,model
predictioniscomparedtothelivingpopulationcollectedbyplankton-nets.

ix

Themodeledspatialdistributionofmostofthespeciescomparesfavorablywith
core-topdata.Themodelpredictionindicatesthatpolarregionsaredominatedby
N.pachyderma(sin.);N.pachyderma(dex.)andG.bulloidesarethemostcommon
speciesinhighproductivityzones;andtropical-subtropicalspecieslikeG.ruberand
G.sacculiferaremoreabundantinoligotrophicwaters.Thepredictedseasonalflux
patternscoincidedwithsediment-traprecordsinmostofthelocations,althoughthe
comparisonwashamperedbyinterannualvariabilitynotcapturedbythemodel.

Usingtheforaminiferamodel,wecarriedoutsensitivityexperimentstostudy
theimentresponseusingaofconstantforaminiferatemperaturtodiffereoentf12◦Cboundaryindicatedconditions.thatfoodAsensitivityavailabilityiexpersa