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
|
Holdings |
Library |
Call Number |
Additional Info |
Location |
Last Modified |
Checkout Status |
NTIS |
PB95-177291 |
Some EPA libraries have a fiche copy filed under the call number shown. |
|
07/26/2022 |
|
Collation |
8p |
Abstract |
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. |