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RECORD NUMBER: 183 OF 197

OLS Field Name OLS Field Data
Main Title Surface inhomogeneity effects on convective diffusion /
Author Briggs, Gary A.
CORP Author Environmental Sciences Research Lab., Research Triangle Park, NC. Meteorology and Assessment Div.
Publisher United States Environmental Protection Agency, Office of Research and Development, Atmospheric Sciences Research Laboratory,
Year Published 1988
Report Number EPA/600/J-88/334
Stock Number PB89-206650
Additional Subjects Atmospheric diffusion ; Urban areas ; Heat flux ; Wind velocity ; Atmospheric models ; Mathematical models ; Reprints ; Convection(Atmospheric) ; Atmospheric turbulence ; Saint Louis(Missouri)
Holdings
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Status
NTIS  PB89-206650 Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy. 01/01/1988
Collation 21 pages ; 28 cm
Abstract
It is suggested that convective scaling, with appropriate extensions, provides the most useful framework for estimating the effects of urban-scale surface inhomogeneities on diffusion in convective conditions. Strong contrasts in surface heat flux exist between cropland, forests, urban areas, and water or marshland surfaces. It is argued that a typical fetch for convective turbulence to readjust to changed heat (or buoyancy) input from the surface below is 2(U/w*)z(j), where U is the mean wind speed in the mixing layer, w* is the convective scaling velocity, and z(j) is the mixing depth. The ratio w*/U is the best index of diffusion rates in moderately to very unstable conditions. General urban effects on heat flux, z(j), and U are discussed separately, then their combined effects on w*/U are estimated. Finally, some examples of heat flux inhomogeneities causing stationary convective features are presented.
Notes
"Reprint article published in Boundary-Layer Meteorology, vol. 45(1988), pp. 117-135." Caption title. "Journal article." Microfiche.
Contents Notes
EPA/600/J-88/334.