Record Display for the EPA National Library Catalog
RECORD NUMBER: 7 OF 7| Main Title | Surface inhomogeneity effects on convective diffusion / | |||||||||||
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| 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) | |||||||||||
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| 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. |
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| Notes | "Reprint article published in Boundary-Layer Meteorology, vol. 45(1988), pp. 117-135." Caption title. "Journal article." Microfiche. |
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| Contents Notes | EPA/600/J-88/334. |