Record Display for the EPA National Library Catalog

RECORD NUMBER: 22 OF 216

Main Title Atmospheric dispersion parameters in plume modeling /
Author Pasquill, F.
Other Authors
Author Title of a Work
Weber, A. H.
Pasquill, F.
CORP Author Environmental Sciences Research Lab., Research Triangle Park, N.C.
Publisher U.S. Environmental Protection Agency, Office of Research and Development, Environmental Sciences Research Laboratory,
Year Published 1978
Report Number EPA-600/4-78-021
Stock Number PB-283 655
OCLC Number 07699482
Subjects Atmospheric diffusion--Mathematical models ; Atmospheric circulation--Mathematical models ; Gaussian processes
Additional Subjects Air pollution ; Atmospheric diffusion ; Plumes ; Mathematical models ; Concentration(Composition) ; Surveys ; Boundary layers ; Point sources
Internet Access
Description Access URL
https://nepis.epa.gov/Exe/ZyPDF.cgi?Dockey=20015LZQ.PDF
Holdings
Library Call Number Additional Info Location Last
Modified
Checkout
Status
EJBD  EPA 600-4-78-021 Headquarters Library/Washington,DC 07/11/2016
EKBD  EPA-600/4-78-021 c.1 Research Triangle Park Library/RTP, NC 03/24/2011
EKBD  EPA-600/4-78-021 c.2 Research Triangle Park Library/RTP, NC 03/24/2011
ELBD ARCHIVE EPA 600-4-78-021 Received from HQ AWBERC Library/Cincinnati,OH 10/04/2023
ESAD  EPA 600-4-78-021 Region 10 Library/Seattle,WA 03/23/2010
NTIS  PB-283 655 Some EPA libraries have a fiche copy filed under the call number shown. 07/26/2022
Collation x, 57 p. : graphs ; 28 cm.
Abstract
A survey of the underlying foundations of the present systems for specification of the atmospheric dispersion parameters for a continuous point source leads to the conclusion that the basis for revision of the current systems is still far from complete, but certain obvious evidence points to desirable changes. The author's previous recommendations on the crosswind spread are reiterated, and a suggested revision for vertical spread as a function of surface roughness, stability, and for the unstable case, the convective velocity scale and mixing depth, is offered.
Notes
"Reproduced by National Technical Information Service, U.S. Department of Commerce, Springfield, Va. 22161." "EPA-600/4-78-021" Bibliographies: p.57.
Contents Notes
A brief survey is given of the present position in the specification of atmospheric dispersion parameters for use in estimating pollutant concentration from a continuous point release. The theoretical indications of the distribution to be expected across a time-mean plum are recalled, with particular reference to the existence of the Gaussian form. Observational evidence, especially as regards the vertical distribution from a surface release, is also recalled, and the practical significance of departure from an assumed Gaussian form is noted. The use of the Taylor statistical theory in the generalized estimation of crosswind spread in quasi-ideal boundary layer flow is briefly summarized. Recent considerations of the behaviour of the crosswind component of turbulence in the surface layer and new developments from laboratory modeling of horizontal dispersion in convective mixing are noted. A brief survey is given of the achievements of gradient-transfer theory and Lagrangian similarity theory in calculating vertical spread from a surface release. New tests against previous dispersion data underline inadequacies in the present approaches in very unstable conditions. Promising developments from the laboratory modeling of a convectively mixed layer and from the 2nd-order-closure modeling of the turbulent fluctuation equations are summarized. The assimulation of theory and experience into practical systems for the specification of [sigma]y and [sigma]z is briefly reconsidered. For [sigma]y a practical procedure based on wind direction fluctuation data is reaffirmed. For [sigma]z a new format which may be envisaged for future composite curves is suggested. Finally, the inherent limitations of practical systems for estimating concentration levels are reiterated.