Ocean Processes in Climate Dynamics: Global and Mediterranean Examples

448 Pages·1994·32.157 MB·English

by  H. Charnock (auth.), Paola Malanotte-Rizzoli, Allan R. Robinson (eds.)

Ocean Processes in Climate Dynamics:
Global and Mediterranean Examples
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SeriesC: Mathematicaland PhysicalSciences-Vol. 419
Ocean Processes in
Climate Dynamics:
Global and
Mediterranean Examples
edited by
Paola Malanotte-Rizzoli
Department of Earth, Atmospheric, and Planetary Sciences,
Center for Meteorology and Physical Oceanography,
Massachusetts Institute of Technology,
Cambridge, Massachusetts, U.S.A.
and
Alian R. Robinson
Division of Applied Sciences,
Department of Earth and Planetary Sciences,
Harvard University,
Cambridge, Massachusetts, U.S.A.
Springer-Science+Business Media, B.V.
Proceedings of the NATO Advanced Study Institute on
Ocean Processes in Climate Dynamics: Global and Mediterranean Examples
Erice, Italy
January 2G-February 2, 1993
A C.I.P. Catalogue record for this book is available from the Library of Congress.
ISBN 978-94-010-4376-2 ISBN 978-94-011-0870-6 (eBook)
DOI 10.1007/978-94-011-0870-6
Printed on acid-free paper
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© 1994 Springer Science+Business Media Dordrecht
Origina11y published by Kluwer Academic Publishers in 1994
Softcover reprint of the hardcover 1s t edition 1994
No part of the material protected by this copyright notice may be reproduced or
utilized in any form or by any means, electronic or mechanical, includ ing photo
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CONTENTS
Preface xv
Listofparticipants
XVll
Air-SeaExchangesandMeridionalFluxes
H. Charnock
1. Air-seaexchanges 1
1.1 Momentumtransfer 1
1.2 Masstransfer S
1.3 Theheatflux 8
1.4 Densityflux 12
2. Meridional heattransport 12
2.1 Errorestimates.................. 16
2.2 Oceanfresh watertransport 21
3. Conclusion 24
Lagrangianand EulerianMeasurementsofOceanTransportProcesses
RussE. Davis
1. Introduction 29
2. EulerianandLagrangianframeworks 30
2.1 Eulerian-averageequations 30
2.2 Lagrangian-averageequations 32
2.3 Comparingthe referenceframes 34
3. Transportmeasuresfrom currentfollowers 3S
3.1 Measuresofstirringanddispersion 3S
3.2 Describingtracerevolution 37
4. Oceanmeasurementsoflateral transport 39
4.1 Taylordiffusivity 39
4.2 Particleseparation 41
v
vi
4.2 Meanvelocitysamplingerrors 42
4.4 Meanvelocitybiases 44
5. Diapycnalfluxes 49
5.1 Large-scalebudgets.. 49
5.2 TheOsborn-Coxmodel. 52
5.3 Samplingdissipation 56
DispersionandMixingintheOcean
Chris Garrett
1. Introduction 61
1.1 Parmneterisation 61
1.2 Sensitivityanalysis 62
1.3 Spectral gap 62
1.4 Threeapproaches. 62
2. Inference 63
2.1 Abyssal basin budgets 63
2.2 TheMediterraneansalttongue 64
2.3 Inversetheories 64
3. Directmeasurement 65
3.1 Eddycorrelation.,................................................................................. 65
3.2 Particledispersion 66
3.3 Relativedispersion 68
3.4 Driftersordye? 69
4. Indirectmeasurements 70
4.1 Microstructure.... 70
4.2 Overturns 71
4.3 Shear 71
5. Processes 72
6. Conclusions 73
6.1 Eddyresolvinggeneral circulationmod,els 73
6.2 Generalcirculationmodels 74
7. Discussion 74
vii
OceanModelsinClimateProblems
JochemMarotzke
1. Introduction 79
1.1 Activeandpassiverolesoftheoceanintheclimatesystem 79
1.2 Multipleequilibriaofthethermohalinecirculation 81
1.3 Mixedthermohaline boundaryconditions 82
1.4 Outlineofthis lecture 85
2. Feedbacksaffectingthe thermohalinecirculation 85
3. Large-scaleair-seaheatexchanges 87
3.1 Doestheoceandrivetheatmosphere,ortheatmospheretheocean?... 87
3.2 Aconceptual model........................ 89
4. Interactionofthehydrologicalcyclewith thethermohalinecirculation 95
5. Numerical modelsofthe thermohalinecirculation 99
5.1 Whichequilibriaarepossible? 99
5.2 Stabilityand variabilityofthethermohalinecirculation 102
5.3 Alternativethermal boundaryconditionsin numerical models 104
6. Summaryandoutlook: towardscoupled processmodels 105
SensitivityStudiesontheRoleoftheOceanin ClimateChange
WilliamR. HollandandFrankO. Bryan
1. Introduction-CMEresultson thermohalineoverturning 111
2. Thesurfaceheatandfresh waterflux parameterizations 113
3. A basicexperiment 118
4. Sensitivityexperiments 119
5. Multiplestablestates 126
6. Openboundaryconditions 131
7. Discussion 131
viii
ModelingtheWindandThennohalineCirculationintheNorth AtlanticOcean
WilliamR. HollandandFrankO.Bryan
1. Introduction-theCommunityModelingEffort 135
1.1 Modelconfiguration 137
1.2 Results 138
2. Improvingsurfaceboundaryconditions 143
3. Open boundaryconditionsfortheCMEmodel 151
4. Internal parameterizationsfortheCMEmodel 153
5. Discussion 153
StudyingThennohalineCirculationintheOceanbyMeansofTransient
TracerData
WolfgangRoether
1. Introduction 157
2. Tracerfeaturesand geochemistry 158
3. Informationfromoceanictracerdistribution 162
3.1 Spreadingandpathways 162
3.2 Processinformationandlow-ordermodels 164
4. Tracerevaluationbymeansofoceancirculationmodels 165
4.1 Systemanalysis models 166
4.2 Oceangeneralcirculationmodels 168
5. Conclusions 168
LaboratoryandNumericalExperimentsinOceanicConvection
John Marshall, J.A. Whitehead and Thorn Yates
1. Introduction 173
2. TheinfluenceoftheEarth'srotationon the convective process 175
2.1 Thermalswithbackgroundrotation 175
ix
2.2 Controllingnon-dimensional parameters 176
3. A laboratoryanalogueofaconvectingchimney 179
4. Scalingideas 182
4.1 Theconvectionlayer 186
4.2 Thegeostrophicallyadjustedendstate 187
4.3 Interpretationoficeexperiment 188
4.4 Oceanographicparameters 188
5. Numerical illustrations 190
5.1 Convectionina neutral ocean 190
5.2 Convectioninastratifiedocean 196
6. Summaryanddiscussion 197
OpenOceanDeepConvection,MediterraneanandGreenlandSeas
F. Schott, M. Visbeck and U. Send
1. Introduction 203
2. TheGulfofLions, NorthwesternMediterranean 205
2.1 Preconditioning 205
2.2 I>eepconvection 207
2.3 Newresultsfrom winter1991/92 209
2.4 Deep-waterproperties: seasonal,interannualand long-termchanges 214
2.5 Possiblerelationsofcoolingandconvectiontolarge-scaleflow 215
3. GreenlandSeaconvectionandtheroleofice 216
3.1 Circulationandpreconditioning 216
3.2 Vertical Velocities and Convection 220
4. Summaryandconclusions 220
TheMediterraneanSeaasa ClimateTestBasin
Chris Garrett
1. Introduction 227
2. Mean heatandwaterbudgetsofthe Mediterranean 228
3. Variability 231
x
3.1 Trends 231
3.2 Seasonalchanges 232
3.3 Interannual variability 232
4. Buoyancyflux 232
5. Models 233
6. Discussion 235
TheMediterraneanSea,a TestAreaforMarineandClimaticInteractions
J.P. BethouxandB. Gentili
1. Yearlybudgets 239
2. Spatialvariabilityofheatand watertransfers 243
3. Recenthydrologicalchanges 245
4. Mediterraneansapropelformation, achangeindeep-waterformations 249
5. Conclusions 251
ThePhysicalandDynamicalOceanographyoftheMediterraneanSea
AllanR. RobinsonandMaryamGolnaraghi
1. Introduction 255
2. Air-seainteractionsandstraitsexchanges 260
3. Waterrnassformation, dispersionandtransformation 264
3.1 Deepwater 266
3.2 LevantineIntermediateWater(LIW)andDeepWater(LOW) 268
4. Circulationanditsvariabilities 273
4.1 Largescale 275
4.2 Subbasinscale 277
4.3 Mesoscale 277
5. Modelling 285
5.1 Watermassmodels 285
5.2 General circulationmodels 288
5.3 Dataassimilationintodynamical models 291