Record Display for the EPA National Library Catalog


OLS Field Name OLS Field Data
Main Title Convection Tank Experiments on Top-Down, Bottom-Up Diffusion.
Author Piper, M. ; Wyngaard, J. C. ; Synder, W. H. ; Lawson, R. E. ;
CORP Author Pennsylvania State Univ., University Park. Dept. of Meteorology. ;National Oceanic and Atmospheric Administration, Silver Spring, MD. Atmospheric Sciences Modeling Div.;Environmental Protection Agency, Research Triangle Park, NC. Atmospheric Research and Exposure Assessment Lab.
Publisher Dec 94
Year Published 1994
Report Number EPA-R821211; EPA/600/A-95/008;
Stock Number PB95-177291
Additional Subjects Atmospheric boundary layer ; Convection currents ; Eddies ; Turbulent diffusion ; Experimental design ; Air flow ; Atmospheric temperature ; Large-eddy simulation
Library Call Number Additional Info Location Last
NTIS  PB95-177291 Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy. 05/26/1995
Collation 8p
Large-eddy simulation (LES) results indicate the scalar diffusion in the convective atmospheric boundary layer (CBL) has interesting properties. A scalar introduced into the bottom of the CBL with no flux through the top (bottom-up diffusion) has a radically different eddy diffusivity profile than a scalar introduced at the CBL top with zero flux through the surface (top-down diffusion). To test the LES results, we designed and implemented a set of experiments in a replica of the original Deardorff-Willis laboratory convection tank. We measured mean gradients and inferred flux profiles of two scalars, temperature and dye concentration, to calculate vertical profiles of the top-down and bottom-up eddy diffusivities. Our experimental results were in good agreement with the LES results.