Journal ArticleDOI
Turbulence-induced millimeter-wave scintillation compared with micrometeorological measurements
Reginald J. Hill,R. A. Bohlander,S. F. Clifford,R. W. McMillan,J.T. Priestly,W.P. Schoenfeld +5 more
TLDR
In this paper, the phase structure function showed a rolloff at large spacings as was expected because the outer scale of the turbulence and log-intensity and phase difference are Gaussian random variables.Abstract:
Scintillations of intensity and phase difference were measured at millimeter wavelengths in a horizontally homogeneous atmospheric surface layer. Simultaneous micrometeorological and optical propagation measurements characterized the clear-air turbulence. Predicted and measured propagation statistics are in good agreement. It is shown that the phase structure function showed a rolloff at large spacings as was expected because the outer scale of the turbulence and log-intensity and phase difference are Gaussian random variables. The mutual coherence function is exp(-D/2) to great accuracy, where D is the sum of phase and log-amplitude structure functions. Estimating heat and humidity fluxes from intensity variances is shown to be valid. >read more
Citations
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Journal ArticleDOI
Propagation of electromagnetic waves in Kolmogorov and non-Kolmogorov atmospheric turbulence: three-layer altitude model
TL;DR: A model of turbulence spectra changing with altitude on the basis of obtained experimental and theoretical data for turbulence profile in the troposphere and lower stratosphere is suggested.
Journal ArticleDOI
Determination of Area-Averaged Water Vapour Fluxes with Large Aperture and Radio Wave Scintillometers over a Heterogeneous Surface Flevoland Field Experiment
W.M.L. Meijninger,A. E. Green,Oscar Hartogensis,W. Kohsiek,J. C. B. Hoedjes,R. M. Zuurbier,H. A. R. De Bruin +6 more
TL;DR: A large aperture scintillometer (LAS) and a radio wave scintillation (RWS) were installed over a heterogeneous area to test the applicability of the Scintillation method as mentioned in this paper, and the water vapour fluxes derived from the combined LAS-RWS system, also known as the two-wavelengthmethod, agreed fairly well with the aggregatedwater vapours derived from in-situeddy covariance measurements.
Journal ArticleDOI
Probability distribution of irradiance for the onset of strong scintillation
Reginald J. Hill,Rod Frehlich +1 more
TL;DR: In this paper, the probability distribution function (PDF) from simulations for an initially spherical wave propagated through homogeneous atmospheric turbulence was calculated and the onset of strong scintillation was calculated.
Journal ArticleDOI
Scintillometer-Based Turbulent Fluxes of Sensible and Latent Heat Over a Heterogeneous Land Surface – A Contribution to Litfass-2003
TL;DR: In this article, the performance of a combined large aperture scintillometer (LAS) and a millimetre wave scintilometer (MWS) for estimating surface fluxes of sensible and latent heat over natural landscape is investigated, using data gathered during LITFASS-2003.
Journal ArticleDOI
Review of optical scintillation methods of measuring the refractive-index spectrum, inner scale and surface fluxes
TL;DR: The background, recent progress and future trends of remote sensing of three environmental parameters using optical scintillation are reviewed in this paper, including the refractive index spectrum of turbulence, the inner scale of turbulence and the surface fluxes of heat, humidity and momentum.
References
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Journal ArticleDOI
Flux-Profile Relationships in the Atmospheric Surface Layer
TL;DR: In this article, the free constants in several interpolation formulas can be adjusted to give excellent fits to the wind and temperature gradient data, and the behavior of the gradients under neutral conditions is unusual, however, and indicates that von Karman's constant is ∼0.35, rather than 0.40 as usually assumed, and that the ratio of eddy diffusivities for heat and momentum at neutrality is ∼1.0.
Journal ArticleDOI
Flux‐gradient relationships in the constant flux layer
A. J. Dyer,B. B. Hicks +1 more
TL;DR: In this paper, an analysis of the Monin-Obukhov function ΦM in the familiar wind profile equation was made using data from two recent expeditions to Gurley (New South Wales) and Hay (New Australia).
Journal ArticleDOI
The Budgets of Turbulent Kinetic Energy and Temperature Variance in the Atmospheric Surface Layer
J. C. Wyngaard,O. R. Coté +1 more
TL;DR: In this paper, the authors measured the shear production, buoyant production, turbulent transport (flux divergence) and dissipation terms in the budget of turbulent kinetic energy, and production and turbulent transport terms in temperature variance budget.
Journal ArticleDOI
Behavior of the Refractive-Index-Structure Parameter near the Ground*
TL;DR: In this article, a semi-empirical theory is developed which relates the refractive index-structure parameter Cn2 in the lowest few tens of meters to the vertical gradients of wind speed and temperature and to a stability parameter.
Journal ArticleDOI
A saturation-resistant optical scintillometer to measure Cn2†
TL;DR: In this paper, a new optical technique for measuring the refractive-index structure parameter Cn2 was described, using relatively large incoherent transmitting and receiving optics, the scintillometer maintains its calibration and path-weighting function throughout the range of observed refractive turbulence values, even to the case of saturated scintillation.