Download or read book Tropospheric Stratospheric Turbulence and Vertical Diffusivities written by S. P. Zimmerman and published by . This book was released on 1980 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: The determination of winds and temperature by rawinsonde allows us to calculate the Richardson number, a measure of atmospheric instability. From this, we can then determine the turbulent atmospheric parameters, diffusivity (K), rate of heat deposition (epsilon), and the vertical turbulent intensity (w2). Comparison of these data, for the spring periods, with contours of residual stratospheric radioactivity demonstrate that, at the tropopause, the isocountours of turbulent diffusivity accurately follow the isodensity contours of the residual radioactivity. We also demonstrate that the rapid cessation of the turbulent diffusivity accurately predicts the level of the tropopause. (Author).
Download or read book Tropospheric Stratospheric Turbulence and Vertical Diffusivities written by S. P. Zimmerman and published by . This book was released on 1980 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The determination of winds and temperature by rawinsonde allows us to calculate the Richardson number, a measure of atmospheric instability. From this, we can then determine the turbulent atmospheric parameters, diffusivity (K), rate of heat deposition (epsilon), and the vertical turbulent intensity (w2). Comparison of these data, for the spring periods, with contours of residual stratospheric radioactivity demonstrate that, at the tropopause, the isocountours of turbulent diffusivity accurately follow the isodensity contours of the residual radioactivity. We also demonstrate that the rapid cessation of the turbulent diffusivity accurately predicts the level of the tropopause. (Author)
Download or read book Stratospheric Turbulence and Vertical Effective Diffusion Coefficients written by N. W. Rosenberg and published by . This book was released on 1975 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Theoretical Explanation of Spectral Slopes in Stratospheric Turbulence Data and Implications for Vertical Transport written by Edmond M. Dewan and published by . This book was released on 1976 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper is motivated by the requirement to improve understanding of vertical motion of pollutants in the stratosphere. One method to estimate vertical transport due to the effects of turbulence is by means of the effective diffusivity coefficient. To calculate this parameter, it is often necessary to know the value of epsilon, the rate of turbulent dissipation. This parameter, epsilon, is also important to know in the context of the global numerical stratospheric simulation models now being created for environmental assessment purposes.
Download or read book Vertical Transport by Small Scale Stratospheric Turbulence written by Edmond M. Dewan and published by . This book was released on 1981 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper reviews the estimates to date of the vertical 'effective diffusion coefficient' for stratospheric small scale turbulence transport, KB. These estimates range (in order of magnitude) from 1.0 sq. meter/s to 0.01 sq. meter/s, that is to say from a value which would make turbulence a dominant factor in stratospheric transport to a value which would make it totally insignificant. Such a large range implies much ignorance in this subject. The various techniques are closely examined and the unanswered experimental questions are exhibited. The conclusion is reached that more experimental work needs to be done before one has a reliable estimate for KB.
Download or read book Mixing in Billow Turbulence and Stratospheric Eddy Diffusion written by Edmond M. Dewan and published by . This book was released on 1979 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: In order to estimate the rate of vertical transport due to turbulence in the stratosphere, it is necessary to know the degree of mixing that takes place in 'Kelvin-Helmholtz billow events.' This is estimated by means of a discrete model and the results are compared with published experimental observations. From these considerations it is concluded that a very large degree of mixing probably takes place in such events, and that, therefore, one must use the relation between the bulk vertical eddy diffusivity and layer diffusivity originally proposed by Rosenberg and Dewan instead of the simple one usually employed.
Download or read book Estimates of Vertical Eddy Diffusion Due to Turbulent Layers in the Stratosphere written by Edmond M. Dewan and published by . This book was released on 1979 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vertical transport in the stratosphere occurs by many processes and the question of the relative importance of stratified turbulence is considered in the context of a 'vertical stack model' described in a previous report. The 'vertical stack model' was designed to estimate the effect of intermittent turbulent layers (separated by essentially laminar flow) and it is here examined in some detail. In particular, a number of less obvious implications are discussed and a list of experimental tests of the model is suggested. It is concluded that the rate of turbulence for vertical transport in the stratosphere remains an open question.
Download or read book Stratospheric Turbulence and Vertical Effective Diffusion Coefficients written by N. W. Rosenberg and published by . This book was released on 1975 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Computations of the observed frequency distribution of the magnitudes of vertical shears of horizontal winds between 5 and 20 km altitude are reported. The probability distribution of turbulent layers for various values of vertical thickness is discussed. An effective vertical-diffusion coefficient, Ke, is estimated from a simple model using this empirical turbulence probability distribution. Specifically, the authors calculate the effect of clear-air turbulence (CAT) upon vertical transport, using a model consisting of a vertical column of thin, randomly-spaced mixing (turbulent) layers separated by thick non-mixing atmospheric layers.
Download or read book Turbulence in the Free Atmosphere written by Nikolaĭ Konstantinovich Vinnichenko and published by Springer. This book was released on 1973 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Feasibility Study for Measuring Stratospheric Turbulence Using Metrac Positioning System written by and published by . This book was released on 1975 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Optical Turbulence Forecasting written by Edmond M. Dewan and published by . This book was released on 1980 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report is a tutorial on the effects of atmospheric turbulence upon systems which rely upon the propagation of LASER beams. In addition to providing a simplified presentation of turbulence theory and optical effects, it describes the state of the art of the new technique of radiosonde estimation of index of refraction fluctuations. Suggestions are given for future research which will help to answer current Air Force needs. The feasibility of some laser systems will depend upon the value of r0, the coherence length (which is related to “C2n” which in turn is related to the degree of turbulence). At present, the statistics of “r0” are inadequate.
Download or read book Theoretical Explanation of Spectral Slopes in Stratospheric Turbulence Data and Implications for Vertical Transport written by Edmond M. Dewan and published by . This book was released on 1976 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper is motivated by the requirement to improve understanding of vertical motion of pollutants in the stratosphere. One method to estimate vertical transport due to the effects of turbulence is by means of the effective diffusivity coefficient. To calculate this parameter, it is often necessary to know the value of epsilon, the rate of turbulent dissipation. This parameter, epsilon, is also important to know in the context of the global numerical stratospheric simulation models now being created for environmental assessment purposes.
Download or read book An Investigation of the Temporal Character of Mesoscale Perturbations in the Troposphere and Stratosphere written by William W. Vaughan and published by . This book was released on 1977 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mixing in Billow Turbulence and Stratospheric Eddy Diffusion written by Edmond M. Dewan and published by . This book was released on 1979 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mixing in Billow Turbulence and Stratospheric Eddy Diffusion written by Edmond M. Dewan and published by . This book was released on 1979 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: In order to estimate the rate of vertical transport due to turbulence in the stratosphere, it is necessary to know the degree of mixing that takes place in 'Kelvin-Helmholtz billow events.' This is estimated by means of a discrete model and the results are compared with published experimental observations. From these considerations it is concluded that a very large degree of mixing probably takes place in such events, and that, therefore, one must use the relation between the bulk vertical eddy diffusivity and layer diffusivity originally proposed by Rosenberg and Dewan instead of the simple one usually employed.
Download or read book Characterization and Prediction of Clear Air and Optical Stratospheric Turbulence for DoD High Altitude Platforms written by and published by . This book was released on 2008 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: Stratospheric Clear Air Turbulence (CAT) is a major challenge to the safety, controllability and flight path optimization of the Global Hawk, Predator and other Unmanned Aerial Vehicles (UAVs) and Platforms. Optical Turbulence (OT) layers impact on the polarization and focusing of laser beams in communication systems and the Airborne Laser (ABL). The completed fundamental research project investigated the microscale physics of the upper troposphere/lower stratosphere (UTLS), closely correlating field measurements, high resolution numerical simulations and nonlinear mathematics to explicitly resolve multiscale turbulent dynamics of polarized inertia-gravity waves in the UTLS region. High performance massively parallel codes for the fully compressible, nonhydrostatic 3D Navier-Stokes equations and advanced data analysis tools for atmospheric characterization were developed and validated. High resolution coupled mesoscale/microscale simulations were carried out to characterize patchy, nonhomogeneous, shear-stratified UTLS turbulence under representative local atmospheric conditions (jetstream and topography). The embedded microscale nests and adaptive vertical gridding near the tropopause fully resolved laminated turbulent structures, with localized shear gradients of vertical velocity and potential temperature in the UTLS region.
Download or read book Practical Meteorology written by Roland Stull and published by Sundog Publishing, LLC. This book was released on 2018 with total page 942 pages. Available in PDF, EPUB and Kindle. Book excerpt: A quantitative introduction to atmospheric science for students and professionals who want to understand and apply basic meteorological concepts but who are not ready for calculus.
