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Zeitschrift für Naturforschung A

A Journal of Physical Sciences

Editor-in-Chief: Holthaus, Martin

Editorial Board: Fetecau, Corina / Kiefer, Claus

IMPACT FACTOR 2016: 1.432

CiteScore 2017: 1.30

SCImago Journal Rank (SJR) 2017: 0.403
Source Normalized Impact per Paper (SNIP) 2017: 0.632

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Volume 29, Issue 7


Turbulent Diffusion with Memories and Intrinsic Shear

C. M. Tchen
Published Online: 2014-06-02 | DOI: https://doi.org/10.1515/zna-1974-0717

The first part of the present theory is devoted to the derivation of a Fokker-Planck equation. The eddies smaller than the hydrodynamic scale of the diffusion cloud form a diffusivity, while the inhomogeneous, bigger eddies give rise to a nonuniform migratory drift. This introduces an eddyinduced shear which reflects on the large-scale diffusion. The eddy-induced shear does not require the presence of a permanent wind shear and is intrinsic to the diffusion. Secondly, a transport theory of diffusivity is developed by the method of repeated-cascade and is based upon a relaxation of a chain of memories with decreasing information. The cutoff is achieved by a randomization which brings statistical equilibrium. The number of surviving links varies in accordance with the number of subranges composing the spectrum. Since the intrinsitc shear provides a production subrange added to the inertia subrange, the full range of diffusion consists of inertia, composite and shear subranges. The theory predicts a variance σ2~t3, t12/5 and t2 and an eddy diffusivity K~l4/3, l7/6 for the above diffusions. The coefficients are evaluated. Comparison with experiments in the upper atmosphere and oceans is made.

About the article

Received: 1974-04-22

Published Online: 2014-06-02

Published in Print: 1974-07-01

Citation Information: Zeitschrift für Naturforschung A, Volume 29, Issue 7, Pages 1101–1111, ISSN (Online) 1865-7109, ISSN (Print) 0932-0784, DOI: https://doi.org/10.1515/zna-1974-0717.

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© 1946 – 2014: Verlag der Zeitschrift für Naturforschung. This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License. BY-NC-ND 3.0

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