Ocean Circulation: Mechanisms and Impacts - Past and Future Changes of Meridional Overturning

Title Page
......Page 3
Copyright
......Page 4
Contents
......Page 5
Preface
......Page 7
Introduction: The Ocean’s Meridional Overturning Circulation......Page 8
REFERENCE......Page 11
1. INTRODUCTION......Page 12
2. DEVELOPMENT OF A QUALITATIVE PICTURE OFTHE ATLANTIC MOC......Page 13
3. EARLY ESTIMATES OF A WEAK ATLANTIC MOC......Page 15
4. THE DEEP WESTERN BOUNDARY CURRENT,STOMMEL AND EARLY INDICATIONS OF ASTRONGER MOC......Page 17
5. THE MOC AND ITS MERIDIONAL HEATTRANSPORT......Page 19
6. TODAY’S PICTURE OF THE ATLANTIC MOC FROMTHE 25°N SECTION......Page 20
7. INDEPENDENT VERIFICATION FOR THE 16-18 SVATLANTIC MOC......Page 22
REFERENCES......Page 24
1. INTRODUCTION......Page 26
2. THEORY AND MODELS......Page 27
3. THE G99 THEORY IN AN OCEAN-ONLY MODEL......Page 30
4. CHANGES IN FLOW PATHWAYS......Page 32
5. THE ROLE OF DENSITY......Page 34
6. THE SINGLE LENGTH-SCALE APPROXIMATION......Page 36
REFERENCES......Page 38
1. INTRODUCTION......Page 40
2. THEORETICAL CONSIDERATIONS......Page 43
3. NUMERICAL MODEL......Page 45
4. STEADY FLOWS IN THE ONE-HEMISPHERE BASIN......Page 47
5. STEADY FLOWS IN THE TWO-HEMISPHERE BASIN......Page 50
6. UNSTEADY FLOWS......Page 53
7. SUMMARY......Page 58
REFERENCES......Page 59
1. INTRODUCTION......Page 60
2. A BIT OF HISTORY......Page 62
3. THE THERMAL WIND, LEVELS-OF-NO-MOTION,PROPERTY TRANSPORTS......Page 63
5. MODEL PROBLEMS......Page 70
6. SPECIFIC PALEOCEANOGRAPHIC CONCERNS......Page 78
7. CONCLUDING REMARKS......Page 79
REFERENCES......Page 80
INTRODUCTION......Page 82
SOURCES OF THE OVERFLOWS......Page 83
OVERFLOW OBSERVATIONS......Page 85
DOWNSTREAM ENTRAINMENT......Page 89
INTERDECADAL OVERFLOW VARIABILITY......Page 90
DISCUSSION......Page 92
REFERENCES......Page 95
1. INTRODUCTION......Page 97
2. THE MEAN CIRCULATION OF THE SUBPOLARNORTH ATLANTIC......Page 98
3. ESTIMATES OF THE MEAN MERIDIONALOVERTURNING CIRCULATION......Page 107
4. LABRADOR SEA CONVECTION VARIABILITY......Page 108
5. WATER MASS AND CIRCULATION VARIABILITYOF THE SUBPOLAR GYRE......Page 110
6. MOC VARIABILITY AT THE EXIT OF THESUBPOLAR NORTH ATLANTIC......Page 113
7. SUMMARY AND OUTLOOK......Page 118
REFERENCES......Page 122
INTRODUCTION......Page 125
FORMATION OF NORTH ATLANTIC DEEP WATER......Page 126
DISTRIBUTION OF CFC-11 IN NADW......Page 127
CFC-11 INVENTORIES IN NADW IN 1997......Page 130
CALCULATION OF THE NADW FORMATION RATEFROM CFC INVENTORIES......Page 132
RATES OF FORMATION OF NADW COMPONENTSCALCULATED FROM CFC-11 INVENTORIES......Page 133
COMPARISON TO OTHER TECHNIQUES......Page 134
REFERENCES......Page 135
1. INTRODUCTION......Page 137
2. DOMINANT CHARACTERISTICS OF OBSERVEDVARIABILITY......Page 138
3. IMPACTS OF ATLANTIC VARIABILITY......Page 141
4. INSIGHTS ON MECHANISMS OF ATLANTICVARIABILITY FROM MODELS......Page 147
5. ATLANTIC VARIABILITY AND CLIMATE CHANGE......Page 149
6. DISCUSSION AND KEY CHALLENGES......Page 150
REFERENCES......Page 153
1. INTRODUCTION......Page 155
2. DECADAL-SCALE MODES......Page 156
3. SENSITIVITY INTEGRATIONS......Page 166
5. MOC AND GLOBAL WARMING......Page 167
6. SUMMARY......Page 171
REFERENCES......Page 172
EXTERNAL FORCING OF A NONLINEAROSCILLATOR......Page 173
THE EFFECT OF THE INSOLATION......Page 175
CONCLUDING REMARKS......Page 178
REFERENCES......Page 180
INTRODUCTION......Page 181
DEFINITIONS AND ASSUMPTIONS......Page 182
NEW APPROACH OF PLATEAU TUNING......Page 185
CHANGES IN DEGLACIAL 14C AGES OF OCEANWATER MASSES......Page 191
DISCUSSION, SPECULATIONS, AND IMPLICATIONS......Page 197
REFERENCES......Page 201
INTRODUCTION......Page 203
MATERIALS AND METHODS......Page 204
CHRONOSTRATIGRAPHY......Page 205
DEEP-WATER δ18O CHANGE ON THE IBERIANMARGIN......Page 206
CONSTRAINING THE MECHANISMS OF INTERHEMISPHERICCLIMATE CHANGE?......Page 210
REFERENCES......Page 213
Mechanisms for an ~7-kyr Climate and Sea-Level Oscillation During Marine Isotope Stage 3......Page 215
1. INTRODUCTION......Page 216
2. DATA ANALYSIS......Page 217
3. CHANGES IN THE AMOC AND CLIMATE......Page 225
4. CHANGES IN ATMOSPHERIC CO2......Page 228
5. THE ORIGIN OF HEINRICH EVENTS......Page 229
6. A MIS 3 CLIMATE OSCILLATION......Page 230
7. THE LAST DEGLACIATION......Page 244
8. CONCLUSIONS......Page 246
REFERENCES......Page 248
INTRODUCTION......Page 253
STUDY AREAS......Page 255
METHODS......Page 256
BENTHIC FORAMINIFERAL Mg/Ca RESULTS......Page 259
MODEL RESPONSE......Page 261
COMPARISON WITH OTHERPALEOCEANOGRAPHIC EVIDENCE......Page 265
CONCLUSION: AN EMERGING PICTURE FOR THEYOUNGER DRYAS......Page 267
REFERENCES......Page 268
INTER-OCEAN VAPOR TRANSPORT......Page 270
THE ROLE OF SEA ICE......Page 273
ADKIN’S ISOLATED ABYSSAL RESERVOIR......Page 275
OCEAN CIRCULATION DURING GLACIAL TIME......Page 278
THE DECLINE IN THE ATMOSPHERE’S14C TO C RATIO......Page 280
THERMOHALINE CIRCULATION INTHE GREENHOUSE WORLD......Page 281
REFERENCES......Page 282
1.1. Observations and Mechanisms of Millennial-Scale Climate Variability......Page 284
1.2. Phasing Relationship of Abrupt Climate Events......Page 285
2. STUDY SITE AND MODERN CLIMATES......Page 286
4. CLIMATIC INTERPRETATION OF THESPELEOTHEM δ18O......Page 287
5. VARIATIONS IN THE BOTUVERÁ δ18O RECORD......Page 288
6.1. Speleothem δ18O Correlations Between Southern Braziland Eastern China......Page 289
6.2. Interhemispheric Anti-Correlationsof Abrupt Climate Events......Page 292
6.4 High-Latitude Versus Tropical Forcing Mechanisms......Page 294
REFERENCES......Page 296
1. INTRODUCTION......Page 300
2. DESCRIPTION OF MODEL AND FRESHWATERPERTURBATION SIMULATIONS......Page 302
3. HIGH LATITUDE NORTH ATLANTIC RESPONSE......Page 305
4. HEAT TRANSPORT RESPONSE......Page 307
5. TROPICAL RESPONSES......Page 313
6. CONCLUSIONS AND DISCUSSION......Page 315
REFERENCES......Page 318
INTRODUCTION......Page 319
A WORKING HYPOTHESIS......Page 320
MODEL DESCRIPTION AND ANALYSIS......Page 322
WIND DRIVEN CIRCULATION......Page 323
BUOYANCY DRIVEN CIRCULATION......Page 326
DISCUSSION AND CONCLUSIONS......Page 335
REFERENCES......Page 336
Antarctic Stratification, Atmospheric Water Vapor, and HeinrichEvents: A Hypothesis for Late Pleistocene Deglaciations......Page 339
INTRODUCTION......Page 340
THE GLOBAL OCEAN OVERTURNING CONSTRAINTAND THE NORTH ATLANTIC......Page 341
CARBON ISOTOPE CONSTRAINTS ON THEIMPORTANCE OF NORTH ATLANTIC VENTILATIONIN DIFFERENT CLIMATES......Page 342
NORTH ATLANTIC VENTILATION SHUTDOWN ANDDEGLACIATION......Page 345
COOLING AND ATMOSPHERIC WATERTRANSPORT......Page 346
ORBITAL PACING......Page 349
SUMMARY AND CONCLUDING REMARKS......Page 350
REFERENCES......Page 351
1. INTRODUCTION......Page 354
2. MODEL CONFIGURATION AND EXPERIMENTDESCRIPTION......Page 355
3. RESULTS......Page 357
4. MECHANISMS ASSOCIATED WITH THE MOCRESPONSE......Page 361
5. DISCUSSION AND CONCLUSIONS......Page 364
REFERENCES......Page 366
1. INTRODUCTION......Page 367
2. FUTURE GREENHOUSE SCENARIOS AND MODELDATA......Page 368
3. PREDICTED CHANGES IN THE WIND STRESS......Page 369
4. DIRECT EFFECT ON DEEP OCEAN CIRCULATION......Page 371
5. MERIDIONAL DENSITY STRUCTURE IN THEUPPER SOUTHERN OCEAN......Page 374
6. WIND ENERGY INPUT TO THE OCEANICGENERAL CIRCULATION......Page 378
7. DISCUSSION......Page 381
REFERENCES......Page 383
1. INTRODUCTION......Page 385
2. LAND-ICE MELTING AND AMOC DYNAMICS......Page 386
3. MODEL AND METHODOLOGY......Page 387
4. RESULTS......Page 389
5. DISCUSSION......Page 392
REFERENCES......Page 393