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The dispersion of a puff of passive contaminant in the constant stress region
Author(s) -
Chatwin P. C.
Publication year - 1968
Publication title -
quarterly journal of the royal meteorological society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.744
H-Index - 143
eISSN - 1477-870X
pISSN - 0035-9009
DOI - 10.1002/qj.49709440110
Subject(s) - eddy diffusion , atmosphere (unit) , constant (computer programming) , dispersion (optics) , turbulence , mechanics , logarithm , position (finance) , physics , similarity (geometry) , meteorology , environmental science , thermal diffusivity , distribution (mathematics) , mathematical analysis , thermodynamics , mathematics , optics , finance , artificial intelligence , computer science , economics , image (mathematics) , programming language
Properties of a dispersing cloud of passive contaminant released from an instantaneous source near the ground in a neutral atmosphere are investigated theoretically. The mean wind satisfies the logarithmic law, and it is assumed that the vertical turbulent transfer can be described by means of an eddy diffusivity. By using some of the results of the Lagrangian similarity theory of Batchelor, it is shown how useful results may then be obtained from the equation describing the distribution of concentration. In particular, expressions are derived for the position of the centre of mass of the cloud and for its downwind and vertical spreads as functions of the time after release. The distribution of material at a given height is also investigated. The paper concludes with a brief discussion of the results and of other applications of the type of technique presented here.