Book contents
- Frontmatter
- Contents
- Preface
- List of symbols
- 1 The general nature of biosphere-atmosphere fluxes
- 2 Thermodynamics, work, and energy
- 3 Chemical reactions, enzyme catalysts, and stable isotopes
- 4 Control over metabolic fluxes
- 5 Modeling the metabolic CO2 flux
- 6 Diffusion and continuity
- 7 Boundary layer and stomatal control over leaf fluxes
- 8 Leaf structure and function
- 9 Water transport within the soil-plant-atmosphere continuum
- 10 Leaf and canopy energy budgets
- 11 Canopy structure and radiative transfer
- 12 Vertical structure and mixing of the atmosphere
- 13 Wind and turbulence
- 14 Observations of turbulent fluxes
- 15 Modeling of fluxes at the canopy and landscape scales
- 16 Soil fluxes of CO2, CH4, and NOx
- 17 Fluxes of biogenic volatile compounds between plants and the atmosphere
- 18 Stable isotope variants as tracers for studying biosphere-atmosphere exchange
- References
- Index
- Plate Section
14 - Observations of turbulent fluxes
Published online by Cambridge University Press: 05 June 2014
- Frontmatter
- Contents
- Preface
- List of symbols
- 1 The general nature of biosphere-atmosphere fluxes
- 2 Thermodynamics, work, and energy
- 3 Chemical reactions, enzyme catalysts, and stable isotopes
- 4 Control over metabolic fluxes
- 5 Modeling the metabolic CO2 flux
- 6 Diffusion and continuity
- 7 Boundary layer and stomatal control over leaf fluxes
- 8 Leaf structure and function
- 9 Water transport within the soil-plant-atmosphere continuum
- 10 Leaf and canopy energy budgets
- 11 Canopy structure and radiative transfer
- 12 Vertical structure and mixing of the atmosphere
- 13 Wind and turbulence
- 14 Observations of turbulent fluxes
- 15 Modeling of fluxes at the canopy and landscape scales
- 16 Soil fluxes of CO2, CH4, and NOx
- 17 Fluxes of biogenic volatile compounds between plants and the atmosphere
- 18 Stable isotope variants as tracers for studying biosphere-atmosphere exchange
- References
- Index
- Plate Section
Summary
In the summer of 1968, scientists at the Air Force Cambridge Laboratories in Bedford, Massachusetts, conducted a surface-layer experiment over a very flat, uniform site in southwestern Kansas . . . The Kansas experiment saw the first systematic application of tower-based sonic anemometry and computer-controlled data acquisition in a field experiment . . . The statistical relationships developed from these measurements, both spectral and time-averaged, have since been tested and compared by many experimenters, and possible inconsistencies have been discussed at length in the literature, but the basic structure revealed by the two experiments remains substantially unchanged.
Kaimal and Wyngaard (1990)Most of the net transport of mass and energy between an ecosystem and the atmosphere occurs through the turbulent wind. As discussed in the last two chapters, turbulence varies greatly in its properties depending on where and when it occurs, but it also exhibits coherency and organization in its motions. Both the variable and coherent aspects of turbulence are induced by features of the earth’s surface; especially by topographic features, such as the location of hills, mountains, and valleys, and canopy characteristics such as depth and roughness. From a theoretical perspective, it had been reasoned since the groundbreaking work in 1954 by Andrei Monin and Alexander Obukhov that near-surface shear forces, in the neutral surface layer above a horizontally homogeneous land surface, could not sustain vertical divergence in the momentum flux. This led to the inevitable conclusion that surface fluxes must be conserved as a function of height in the surface layer, which in turn led to the concept of a “constant flux layer.” In the late 1950s and early 1960s several research groups took up the aim of validating these theoretical predictions – an aim that required careful observations above flat, simple terrain. The initial experiments conducted in Kansas (and later in Minnesota) in the late 1960s did indeed validate the predictions and this validation has withstood numerous subsequent tests and debates. As referenced in the paper cited above from Kaimal and Wyngaard, after more than 30 years of testing, the tenets of these early experiments are still widely accepted and used.
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- Terrestrial Biosphere-Atmosphere Fluxes , pp. 327 - 351Publisher: Cambridge University PressPrint publication year: 2014