SCOPE 57 Particle Flux in the Ocean

Transcription

1 SCOPE 57 Particle Flux in the Ocean Edited by VENUGOPALAN ITTEKKOT PETRA SCHAFER SCOPEIUNEP International Carbon Unit Universitat Hamburg, Germany SUSUMU HON JO Woods Hole Oceanographic Institution Woods Hole, MA, USA PEDRO J. DEPETRIS Universidad National de Cordoba Cordoba, Republica Argentina Published on behalf of the Scientific Committee on Problems of the Environment (SCOPE) of the International Council of Scientific Unions (ICSU), and the United Nations Environment Programme (UNEP) by JOHN WILEY & SONS Chichester New York Brisbane Toronto Singapore

2 Contents Foreword Hartmut Grassl Preface John W. B. Stewart Bibliography - Carbon Unit Contributors xv xvii xix xxi 1 Particle Flux in the Ocean: Introduction 1 V. Ittekkot 1.1 Background Particle Flux and the Marine Carbon Cycle Acknowledgments References 6 2 Remote Sensing of Parameters Relevant to the Particle Flux in the Ocean Using Meteorological Satellites 7 P. Schliissel 2.1 Introduction Meteorological Parameters Influencing the Environment of Phytoplankton Blooms Quantities Driving the Vertical Exchange in the Upper Ocean Parameters Relevant to Transport and Deposition of Lithogenic Particles Future Perspectives References 15 3 The Atmospheric Transport of Particles to the Ocean 19 J. M. Prospero 3.1 Introduction Aerosol Distributions Over the Oceans Mineral Dust Introduction North Africa and the North Atlantic Concentrations and Seasonal Trends Aerosol Chemical Properties Relationship of Dust Transport to Rainfall in Africa Meteorology of Long Range African Dust Transport 28

3 viii Pacific Studies Indian Ocean and the Arabian Sea Summary Mineral Particle Deposition to the Oceans Source Strengths Dust Deposition Rates Comparison With Aeolian Deposition Rates Long Range Dust Transport and Climate Wind Erosion and Climate The Role of Humans Modeling Dust Generation and Transport Effects of Aeolian Inputs to the Oceans Conclusions Acknowledgments References 45 4 Riverine Transfer of Particulate Matter to Ocean Systems 53 P. J. Depetris 4.1 Introduction Riverine Transport of Carbon and Minerals Factors Controlling Sediment Yield The Role of Exceptional Climatic Events An Assessment of Sediment Inputs into the SW Atlantic: A Case Study Concluding Remarks References 66 5 Particle Flux in the Ocean: Oceanographic Tools 71 V. L. Asper 5.1 Introduction Direct Flux Measurements Hydrodynamic Bias Swimmers Remineralization/Decomposition of the Sample Particle Abundances Sinking Speeds Summary References 81 6 Evaluation of Sediment Traps with Naturally Occurring Radionuclides 85 M. P. Bacon 6.1 Introduction Moored Sediment Traps in the Deep Ocean Sediment Traps in the Upper Ocean Conclusions 89

4 ix 6.5 Acknowledgments References 90 7 Fluxes of Particles to the Interior of the Open Oceans 91 S. Honjo 7.1 Introduction Ocean Particle Flux: Definition, Units and Attributes Methods of Studying Ocean Particles Sediment Traps Time-Series Array and Synchronization Constraints in Measuring Particle Fluxes with Sediment Traps Sample Integrity Swimmers Microbial Growth and Degradation of Samples In Situ Sediment Trap Intercomparison in the Deep Water Column Self Calibration of Particle Fluxes by Radionuclides Sample Sharing and Laboratory Analyses What are Settling Particles? Origin of Settling Particles The Constituents of Settling Particles The CaCCb Component The SiCb Component Organic Matter The Lithogenic Component Particle Removal Processes Removal Processes of Primary Production by Particles "Leaky" Belt Conveyor Need for Ballast Settling Particles vs. Suspended Particles SettlingRates of Particles Estimation of the Residence Time of Particles from Off-Setting Benchmarks Settling Speed of Particles Reverse Estimate of the Succession of an Upper Ocean Event Mesoscale Eddies and Vertical Variability of Fluxes Alteration of Settling Particles Inorganic Carbon: CaCO Organic Matter and Organic Carbon Biogenic S1O Vertical Increase of Lithogenic Particle Fluxes Particle Flux in the Interior of the Very Deep Ocean Trenches in the Pacific Seasonal and Geographical Variability 133

5 x Particle Fluxes in the Margin Contrast Between and in the Global Basins Seasonal and Interannual Variability of Particle Fluxes North Atlantic and North Pacific Pacific and Atlantic Southern Ocean Equatorial Pacific Summary and Conclusions Outlook Acknowledgments References Nitrogen and Carbon Isotopic Tracers of the Source and Transformation of Particles in the Deep Sea 155 M. A. Altabet 8.1 Introduction Isotopic Fractionation During Biogeochemical Reactions Source Effects - 15 N Source Effects - 13 C Transformation Effects - Surface Ocean Transformation Effects - Water Column and Sediment Surface The JGOFS North Atlantic Bloom Experiment - A Case Study Near-Surface Time-Series Signals in 5 13 N and 8 13 C Near-Surface Formation of Sinking Particles Comparison of Near-Surface and 1000 m Isotopic Signals Modifications of the Large Particle Flux Below 1000 m Summary and Recommendations for Further Research References Temporal Variability of Particle Flux in the Deep Sargasso Sea 185 W. G. Deuser 9.1 Introduction The Annual Cycle Other Periods Episodic Events What is Needed? Acknowledgments References Seasonal and Interannual Particle Fluxes in the Eastern Equatorial Atlantic from 1989 to 1991: ITCZ Migrations and Upwelling 199 G. Fischer and G. Wefer 10.1 Introduction Material and Methods Oceanographic and Biological Setting Ocean Currents Results and Discussion 203

6 xi Seasonality and Interannual Variability of Fluxes and Compositions Northern Guinea Basin Sites (GBN) Southern Guinea Basin Sites (GBS) Annual Fluxes and Year-to-Variations Comparison Between the Northern (GBN) and Southern Sites( GBS) Summary and Conclusions Acknowledgments References Preliminary Data on Particle Flux off the Sao Francisco River, Eastern Brazil 215 T.C. Jennerjahn, V. Ittekkot and C.E. V. Carvalho 11.1 Introduction Materials and Methods Results and Discussion Acknowledgements References Organic Carbon Fluxes and Sediment Biogeochemistry on the French Mediterranean and Atlantic Margins 223 H. Etcheber, S. Heussner, O. Weber, A. Dinet, X. Durrieu de Madron, A. Monaco, R. Buscail andj.c. Miquel 12.1 Introduction Sampling Sites and Strategy Mediterranean Sites Atlantic Sites Results Spatial Variations in Total Mass and Organic Carbon Fluxes Mediterranean Sites Atlantic Sites Seasonal Variations in Total Mass and Organic Carbon Fluxes Mediterranean Sites Atlantic Sites Biogeochemistry of Surficial Slope Sediments Discussion Importance of Dynamical Factors on the Transfer of Particles Importance of Advection Seasonal Variability Benthic Response to Organic Particle Fluxes on Margins Conclusions References 239

7 xii 13 Abiotic and Biotic Forcing on Vertical Particle Flux in the Southern Ocean 243 U. V. Bathmann 13.1 The Scenarios Winter Spring Autumn Conclusion Acknowledgments References Processes Determining Seasonality and Interannual Variability of Settling Particle Fluxes to the Deep Arabian Sea 251 B. Haake, T. Rixen, T. Reemtsma, V. Ramaswamy and V. Ittekkot 14.1 Introduction Study Area Methods Sample Analyses Results and Discussion Processes Determining Seasonalities of Biogenic and Lithogenic Fluxes Sources and Decomposition of Organic Matter Interannual Variations Conclusions Acknowledgments References Fresh Water Influx and Particle Flux Variability in the Bay of Bengal 271 P. Schdfer, V. Ittekkot, M. Bartsch, R. R. Nair andj. Tiemann 15.1 Introduction Study Area Methods Sampling Analyses Wind Speed and Sea Surface Temperature Total and Component Fluxes Northern Bay of Bengal Central Bay of Bengal Southern Bay of Bengal Interannual Variability Seasonal Signals Total and Component Fluxes Comparison With Other Marine Regions General Discussion 286

8 xiii 15.8 Conclusions Acknowledgments References Fluxes of Paniculate Matter in the South China Sea 293 M. G. Wiesner, L. Zheng, H. K. Wong, Y. Wang and W. Chen 16.1 Introduction Climate and Hydrography Materials and Methods Results Northern South China Sea Central South China Sea Discussion Conclusions Acknowledgments References Vertical Particle Flux in the Western Pacific Below the North Equatorial Current and the Equatorial Counter Current 313 S. Kempe and H. Knaack 17.1 Introduction Materials and Methods Discussion of Results Acknowledgments References Vertical Particle Flux in Lake Baikal 325 S. Kempe and M. Schaumburg 18.1 Introduction Lake Baikal Material and Methods Sediment Trap Mooring Analytical Methods Discussion of Results Dissolved Fraction and Remineralization Paniculate Fraction Organic Matter SEM Investigations Conclusions Acknowledgments References Appendix Particle Flux in the Ocean: Summary 357 V. Ittekkot 19.1 Introduction 357

9 xiv 19.2 Particle Sources Methods and Problems Results from Experiments Environmental Signals Particle Flux and Carbon Storage in the Deep Sea General Conclusions References 365 Index 367