Contents

Contents

List of Contributors

About the Companion Website

Chapter 1: What is a Coherent Flow Structure in Geophysical Flow?

1.1 Introduction

1.2 From random turbulence to coherent flow structures

1.3 Coherent flow structures in low Reynolds-number flows over smooth boundaries

1.4 Large-scale, high Reynolds-number coherent flow structures

1.5 Does scale matter?

1.6 What is the difference between the mean flow and CFS?

1.7 Coherent flow structures within geophysical flows: future research needs

Chapter 2: Structure of Turbulent Boundary Layers

2.1 Introduction

2.2 Eddy structures

2.3 Interactions of eddies on different scales

2.4 Extracting coherent structure from geophysical flows

2.5 Conclusions

2.6 Acknowledgements

Chapter 3: Structural Attributes of Turbulent Flow over a Complex Topography

3.1 Introduction

3.2 Experiments

3.5 Conclusions

3.6 Acknowledgements

Chapter 4: Coherent Flow Structures in the Pore Spaces of Permeable Beds underlying a Unidirectional Turbulent Boundary Layer: A Review and some New Experimental Results

4.1 Introduction

4.2 Flow across a permeable boundary layer: background

4.3 Boundary layer structure in the freeflow region over permeable beds

4.4 Flow within the transition layer of permeable beds

4.6 Summary and challenges for future work

4.7 Acknowledgements

Chapter 5: Instabilities in Stratified Shear Flow

5.1 Introduction to Kelvin–Helmholtz and Holmboe instabilities

5.2 One-sidedness

5.3 Application of the Taylor–Goldstein equation to asymmetric profiles

5.5 Field observations

5.6 Conclusions

Chapter 6: Scalar Turbulence within the Canopy Sublayer

6.1 Introduction

6.2 A brief review of scalar turbulence inside canopies

6.4 Scalar turbulence within the CSL

6.5 Summary and conclusions

6.6 Acknowledgements

Chapter 7: On the Structure of Wall Turbulence in the Thermally Neutral Atmospheric Surface Layer

7.1 Introduction

7.2 Field scale: atmospheric surface layer

7.3 Laboratory scale: turbulent boundary layer

7.5 Discussion and conclusions

Chapter 8: Critical Reflections on the Coherent Flow Structures Paradigm in Aeolian Geomorphology

8.1 Introduction

8.2 Coherent flow structure end-member reference states

8.3 Flow structures over flat sandy surfaces

8.4 Flow structures over dunes

8.6 Summary and conclusions

Chapter 9: Coherent Flow Structures in Vegetated Channels

9.1 Introduction

9.2 Coherent structures in vegetated channels

9.4 Acknowledgements

Chapter 10: Coherent Eddy Structures over Plant Canopies

10.1 Introduction

10.2 Evidence for organized motion

10.3 Buoyancy forcing

10.4 Summary and conclusions

10.5 Acknowledgements

Chapter 11: SPIV Analysis of Coherent Structures in a Vegetation Canopy Model Flow

11.1 Introduction

11.2 Experimental setup

11.4 Discussion and conclusion

11.5 Acknowledgements

Chapter 12: Calculation and Eduction of Coherent Flow Structures in Open-Channel Flow Using Large-Eddy Simulations

12.1 Introduction

12.2 Method of LES

12.4 Conclusions

Chapter 13: Detection and Analysis of Coherent Flow Structures in a Depth-Limited Flow over a Gravel Surface

13.1 Introduction

13.2 Previous approaches to study CFS over gravel surfaces

13.3 Methodology

13.5 Discussion

13.6 Acknowledgements

Chapter 14: COHSTREX: Coherent Structures in Rivers and Estuaries Experiment

14.1 Introduction

14.2 Stratified flow experiment

14.3 Unstratified flow experiment: thermal imaging

Chapter 15: Intermittent Suspension and Transport of Fine Sediment over Natural Tidal Bedforms

15.1 Introduction

15.2 Field site and data acquisition

15.3 Data analysis methods

15.5 Discussion

15.6 Conclusions

15.7 Acknowledgements

Chapter 16: Large-Scale Coherent Flow Structures in Alluvial Pools

16.1 Introduction

16.2 Background

16.5 Discussion and conclusion

Chapter 17: From Macroturbulent Flow Structures to Large-Scale Flow Pulsations in Gravel-Bed Rivers

17.1 Introduction and research context

17.4 Discussion

17.5 Implications and conclusions

17.6 Acknowledgements

Chapter 18: Coherent Secondary Flows over a Water-Worked Rough Bed in a Straight Channel

18.1 Introduction

18.4 Discussion

18.5 Conclusions

18.6 Acknowledgements

Chapter 19: Coherent Flow Structures, Initiation of Motion, Sediment Transport and Morphological Feedbacks in Rivers

19.1 Introduction

19.2 Grain-flow interaction: recent developments

19.3 Fluctuating fluid forces

19.4 Particle dislodgement paradox

19.5 Resolution of the particle dislodgement paradox

19.6 Analytical formulation

19.7 Experimental results

19.8 Thoughts on coherent structures and grain entrainment

19.9 Some additional thoughts on the impulse concept and particle entrainment

19.10 Conclusion

19.11 Acknowledgement

Chapter 20: Turbulence Modulation by Suspended Sediment in a Zero Mean-Shear Geophysical Flow

20.1 Introduction

20.4 Discussion

20.5 Conclusions

20.6 Acknowledgement

Chapter 21: Effect of Migrating Bed Topography on Flow Turbulence: Implications for Modelling Sediment Transport

21.1 Introduction

21.2 Characterization of bed topography

21.3 Flow velocities above migrating bed forms

21.4 Turbulence patterns modulated by bed forms

21.5 Sediment transport modelling

21.6 Summary and concluding remarks

21.7 Acknowledgements

Chapter 22: Turbulence Structure and Sand Transport over a Gravel Bed in a Laboratory Flume

22.1 Introduction

22.2 Materials and methods

22.3 Results and discussion

22.4 Conclusions

Chapter 23: Coherent Structures and Mixing at a River Plume Front

23.1 Introduction

23.2 Background

23.3 Field campaign and measurements

23.5 Comparison to prior field and laboratory results

Chapter 24: Interfacial Waves as Coherent Flow Structures associated with Continuous Turbidity Currents: Lillooet Lake, Canada

24.1 Introduction

24.3 Results and discussion

24.4 Conclusions