Transport Phenomena in the Biosphere

Transport Phenomena in the Biosphere episodes:

• February 05, 201806: Capturing all relevant scales of biosphere-atmosphere exchange - Measurements and computations, 11.08.2017

  06 |

  0:00:00 Start

  0:01:26 Motivation

  0:07:51 The spectral gap

  0:12:18 Ecosystem-Atmosphere Interactions

  0:20:41 Historical overview of the energy balance closure problem

  0:25:29 Hypotheses for potential reasons of the energy balance closure problem

  0:27:49 Research approach and methods

  0:31:56 Wavelet analysis

  0:36:06 Large-eddy simulation

  0:42:13 Scale-crossing field compaigns

  0:42:19 BOREAS

  0:44:12 TRENO preAlpine Observatory

  0:45:17 ScaleX

  0:47:18 TERENO lower Rhine/Eifel Observatory

  0:48:09 Yatir forest in Israel

  0:48:46 Selected results

  0:48:47 Flow distortion error of sonic anemometers

  0:53:45 Boreas Cande-Lake runs

  0:58:11 Evaluation of energy balance closure parameterizations

  1:01:42 Meso-skaligen Transport (3D)

  1:15:25 Parameters for closure model

  1:22:27 Partitioning of the total flux

  1:31:34 Conclusions

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• January 30, 201816: Fish behaviour in response to hydrodynamic stimuli, 17.08.2017

  16 |

  0:00:00 Start

  0:01:22 Acknowledgement

  0:02:00 Introduction

  0:09:35 The drag function D

  0:13:04 Methods

  0:17:47 Flow field (ADV measurements)

  0:20:53 Space used vs Space sampled

  0:22:22 Hydrodynamic preference curves

  0:23:38 Specialized Behaviours Zones (SBZ)

  0:26:25 Results

  0:29:55 Results: How do other hydrodynamic metrics perform?

  0:33:11 Drag Functions vs Mean Velocities

  0:35:30 Conclusions

  0:37:27 What about downstream migration?

  0:38:43 Acknowledgement

  0:39:39 Introduction

  0:45:27 Methods

  0:52:19 Methods: Numerical simulations

  0:55:09 Methods: Behavioural analysis definitions

  0:56:59 Results: Eels trajectories in the upstream part of the site

  1:01:21 Discussion

  1:07:18 Conclusions

  1:09:15 References

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• January 30, 201815: Eco-Hydraulics and life in moving fluids, 17.08.2017

  15 |

  0:00:00 Start

  0:01:30 Lectures outline

  0:04:00 Lecture 1.1 – An introduction to Eco–Hydraulics and fish locomotion

  0:04:05 What is Eco–Hydraulics?

  0:05:43 Fish–migration

  0:07:12 Hydraulic barriers and threats

  0:16:04 The big picture

  0:19:00 Fish locomotion

  0:31:56 Fish sensing

  0:45:36 Sight (slightly off topic)

  0:47:30 References

  0:48:10 Lecture 1.2 – Swimming and living in hydrodynamiclly–complex environments

  0:48:33 The big picture

  0:49:02 Hydrodynamically–complex environments

  0:50:05 Turbulence in open channel flows

  1:08:04 Swimming in turbulent flows

  1:32:27 Other energy–saving strategies

  1:38:07 Summary

  1:38:43 Refrences

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• January 30, 201812: Plant water movement in xylem and phloem: A new perspective, 16.08.2017

  12 |

  0:00:00 Start

  0:00:44 Why study plants?

  0:02:09 Agricultural production

  0:03:54 Plant vascular transport

  0:05:58 Drought kills trees

  0:06:56 Question: Why do plants need (so much) water?

  0:08:02 Exchange of water for CO2

  0:08:27 Cost of CO2 Diffusion and Fick's law

  0:14:32 Transport Processes: Diffusion and advection

  0:16:08 The Advection-Diffusion equation

  0:19:10 Wood microstructure

  0:21:25 Question: What pressures are needed to drive flow?

  0:25:23 Pressure-drop/Flow rate

  0:28:10 Transport Processes: The Navier-Stokes Equation

  0:36:29 The Stokes equation Hagen-Poiseuille law

  0:38:20 Analogy between electric and fluidic systems

  0:39:53 Sugar transport

  0:42:12 What powers sugar transport?

  0:45:01 Taking the blood pressure of plants

  0:51:07 The Münch mechanism Osmotic pressure pump

  0:52:53 The leaf is an osmotic pump

  0:54:57 Synthetic Phloem: Experiments by Münch (1927)

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• January 30, 201807: Turbulent Structure in Plant Canopies, 11.08.2017

  07 |

  0:00:00 Start

  0:00:50 Reminder-where did we get to on Wednesday?

  0:03:23 Time-Trace of velocity fluctuations-sweeps and ejections

  0:05:40 Ejection/sweep ratios (neutral conditions)

  0:08:43 Large-eddy simulation of canopy flows

  0:09:34 ISL and Canopy Layer Velocity Profiles

  0:10:53 Inflexion point in the velocity profile at canopy top is inevitable

  0:14:47 The Mixing Layer Hypothesis

  0:39:36 Summarizing the Mixing Layer Hypothesis

  0:51:16 ABL-scale instabilities

  0:57:57 Canopy instability process in strong shear (below downdrafts)

  1:11:34 Summary of Canopy-ABL coupling in neutral to convective conditions

  1:24:00 Final Comment

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• January 30, 201809: Society as a Complex System - Can we find a safe and just operating space for humanity?, 12.08.2017

  09 |

  0:00:00 Start

  0:00:45 What are the Sustainable Development Goals?

  0:02:12 Biophysical Planetary Boundaries – Staying in the Holocene

  0:04:11 Social Planetary Boundaries – can we live within the doughnut?

  0:04:50 These biophysical and social boundaries are fundamentally different

  0:06:09 What is a complex system?

  0:08:05 Emergence

  0:11:47 Self organization – Attractors

  0:14:51 Complexity versus Chaos

  0:18:25 History of the world in two graphs: 1, Population and technology

  0:20:15 History of the world in two graphs: 2, Population and wealth

  0:21:02 Attractors in the Human-Earth system

  0:22:38 The Malthusian trap-a social attractor for most of human history

  0:26:45 Escaping the Malthusian Trap

  0:28:37 In the Post-industrial World, a minimal description of the Human-Earth System must include societal dynamics

  0:30:27 We will try to construct a systems description

  0:30:59 Population: the Fertility-mortality balance and its link with wealth

  0:34:20 The Key Feedback from Mortality to Fertility

  0:38:23 Fertility-mortality balance-the effect of urban living

  0:39:47 Generation of wealth

  0:41:10 Generation of wealth-economic output

  0:44:17 Social State

  0:52:51 Transitioning between Natural State and Open Access Order

  0:57:53 Not a new Idea

  0:59:02 Social State

  1:00:39 Biospheric State

  1:01:27 Tracing the links and feedbacks between the four state variables

  1:02:17 Population

  1:03:49 Economic output

  1:05:09 Societal State

  1:07:50 State of the Biosphere

  1:13:32 Emergence and Coarse graining

  1:14:50 Effect of climate change on suitability of land for growing crops

  1:20:20 Syrian Civil War

  1:24:39 The known Unknowns

  1:25:40 We can examine the system description

  1:27:30 Can the trajectory of the human-earth system be understood...?

  1:28:27 some first conclusions

  1:30:33 can understanding the human-earth system as a complex system help?

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• January 30, 201805: Models and predictions: Basic ingredients, dimensionless numbers, predictions versus predictability - and what can go wrong, 10.08.2017

  05 |

  0:00:00 start

  0:02:19 Structure of Talk

  0:02:54 Introduction

  0:09:08 The purpose of models

  0:15:55 Basic ingredients of models

  0:19:26 Predictability and determinism

  0:22:43 Nonlinear effects (Deterministic chaos)

  0:27:46 Verification of models –– ''non–verifiable'' models

  0:30:07 Verification of models –– no-analog communities

  0:32:19 Computing models –– alternatives to general relativity

  0:35:37 Computing models –– heuristic vs. physically based models

  0:40:31 Extrapolation of models

  0:44:28 Constituents of Climate Models

  0:45:27 Climate Models: Basic variables

  0:46:41 Climate Models: System of equations

  0:47:23 Climate Models: Initial and boundary conditions

  0:47:55 Climate Models: Straightforward solutions of the equations

  0:51:25 Model zoo: Increasing complexity of models

  0:53:18 Climate Models: Practical problems

  0:55:52 Forecast: Changing boundary conditions

  0:56:54 Forecast: Changing boundary conditions

  0:57:56 Summary

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• January 29, 201814: Physical limits on plant size and their organs, 16.08.2017

  14 |

  0:00:00 Start

  0:01:52 Literature

  0:01:55 Centennial of On Growth and Form by D'Arcy Thompson

  0:02:44 Question: Why no wheels in nature?

  0:03:31 Example: Why no wheels?

  0:04:37 Question: What drives evolution in biological systems?

  0:04:54 Energetics of Evolution

  0:06:50 Example: Size of living organisms

  0:07:29 Bacterial size limited by feeding strategy

  0:11:12 Sugar transport

  0:11:45 The leaf is an osmotic pump

  0:12:42 First mathematical model

  0:14:24 Later mathematical model

  0:15:14 Phloem models are complex

  0:15:54 Resistor model for phloem flow speed

  0:18:09 Optimal design of an osmotic pump

  0:22:04 Physical limits to leaf size

  0:22:59 Theophrastus, 350 BC

  0:26:22 The global spectrum of plant form and function

  0:27:55 Resistor model for phloem flow speed

  0:28:56 limits to leaf size

  0:30:29 Upper limits to leaf size

  0:31:07 Lower limits to leaf size

  0:35:09 Can we engineer plants that produce more sugar?

  0:36:09 Drawing ''blood'' from a plant

  0:36:41 Plants treat fluorescein as sugar!

  0:38:04 Confocal Microscope – Photobleaching

  0:38:58 Microfluid model

  0:39:58 Plant sugar concentration

  0:41:23 Sugar flow in plants

  0:42:38 Sugar mass flow

  0:42:56 Plants are optimized for efficient transport

  0:43:54 Crop plants have highest concentration

  0:44:40 iPhloem 2017

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• January 29, 201810: An introduction to the soil-root-system, 14.08.2017

  10 |

  0:00:00 Start

  0:00:27 An introduction to the soil-root-system

  0:01:59 Bulk Soil Properties Defined

  0:07:58 Representative Elementary Volume (REV) and the continuum hypothesis

  0:11:20 State equation for soil water

  0:13:12 Fluxes and flow of water

  0:14:41 Text-book view-Analogy to other transport laws

  0:21:50 Fluxes and flow of water

  0:23:31 Fluxes and flow of water: The driving gradient

  0:30:48 An 'ad-hoc' derivation of Darcy's law (for saturated conditions)

  0:40:44 Darcy-Forchheimer law at Moderate Reynolds Number

  0:43:29 Darcy's Law and the Hagen-Poiseuille equation

  0:45:11 An 'ad-hoc' derivation of Darcy's law

  0:50:21 Simplified mathematical representations

  0:53:58 State Equation with roots

  0:55:49 Dynamic Responses

  0:56:35 Broader implications of case study for Soil moisture dynamics and climate

  0:57:45 Background-Soil moisture dynamics and climate

  0:58:54 Experimental results

  1:00:43 Qualitative Analysis of Soil Moisture Response to Rainfall Fluctuations

  1:01:17 Depth-Averaged continuity

  1:04:08 Sample Time Series Measurements from Duke Forest, Durham, NC

  1:05:22 Modeling Soil Moisture Dynamics: ET-s relation

  1:07:02 Spectral Analysis of Soil Moisture

  1:13:43 Implications to climate

  1:14:17 Qualitative Analysis- Systems Approach

  1:14:46 Root Water Uptake

  1:16:49 Soil moisture simulations

  1:19:49 Future Research Trends

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• January 29, 201808: Life with an Altitude: A biosphere-Atmosphere Perspektive, 12.08.2017

  08 |

  0:00:00 Start

  0:01:20 Life with an Altitude

  0:02:41 The Eagle's Perspective

  0:04:56 The Flux Sensor's Perspective

  0:05:39 Surface- Atmosphere Exchange over Inhomogeneous Terrain

  0:07:17 Pattern: Spatial Scales

  0:07:55 Landscape: Impose Pattern and Scale

  0:08:40 Is this forest homogeneous?

  0:09:17 Measured Variability depends on Resolution:

  0:12:28 Plant-Environment Interaction: CO2

  0:14:25 Micrometeorological Flux Measurements:

  0:16:51 The Flux Footprint

  0:25:44 Tigerbush (Niger)

  0:27:05 Variations of Source Areas (using FSAM)

  0:29:33 Tigerbush after FSAM-Filtering

  0:32:40 Variation of Location Bias (using FSAM)

  0:34:59 Summary

  0:36:19 Does the Footprint Concept Actually Work?

  0:37:14 ''Field of View'' / Footprint Varies with Time

  0:38:28 Is the Vancouver Suburban Study Area Homogeneous?

  0:41:45 Measured Spatial Variability of Sensible Heat Flux (QH) in Residental Vancouver Area(1986)

  0:46:42 Morgan-Monroe State Forest (Indiana)

  0:49:25 Location and shape of the footprint...

  0:52:09 Original NDVI:

  0:55:06 8–Day Flux Footprint Composite

  0:55:58 Conclusions

  0:57:22 Flow over Inhomogeneous Surfaces

  1:08:38 Asymmetric Shear-Stress Response to Step-changes in Surface Roughness

  1:13:33 Surface Texture Parameters

  1:18:15 Flow over Inhomogeneous Surfaces

  1:28:35 Take home points:

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