| Main Title |
Vertical Diffusion in Small Stratified Lake: Data and Error Analysis. |
| Author |
Hondzo, M. ;
Ellis, C. R. ;
Stefan, H. G. ;
|
| CORP Author |
Minnesota Univ.-Duluth. St. Anthony Falls Hydraulic Lab.;Environmental Research Lab.-Duluth, MN. |
| Publisher |
cOct 91 |
| Year Published |
1991 |
| Report Number |
EPA-R-816230-01-0; EPA/600/A-93/003; |
| Stock Number |
PB93-149185 |
| Additional Subjects |
Ryan Lake ;
Stratification ;
Thermal conductivity ;
Sediments ;
Limnology ;
Temperature gradients ;
Turbulent diffusion ;
Thermoclines ;
Eddies ;
Heat flux ;
Heat transfer ;
Error analysis ;
Charts ;
Mathematical models ;
Minnesota ;
Reprints ;
Hypolimnion
|
| Holdings |
| Library |
Call Number |
Additional Info |
Location |
Last
Modified |
Checkout
Status |
| NTIS |
PB93-149185 |
Some EPA libraries have a fiche copy filed under the call number shown. |
|
07/26/2022 |
|
| Collation |
18p |
| Abstract |
Water temperature profiles were measured at 2-min intervals in a stratified temperate lake with a surface area of 0.06 sq km and a maximum depth of 10 m from May 7 to August 9, 1989. The data were used to calculate the vertical eddy diffusion coefficient K sub z in the hypolimnion. The depth was representative of a large number of lakes in the north central United States. K sub z was calculated over time intervals of 1 to 15 days and varied from 0.001 to 0.1 sq cm/s. A numerical model was developed for heat conduction in the sediments, and heat flux between water and sediments was incorporated into the relationship from which eddy diffusivity was estimated. Heat flux between water and lake sediments, a term commonly neglected, was found to be important in the K sub x estimation. K sub z values were related to stratification stability as measured by the Brunt-Vaisala frequency N using Welander's expression of the form K sub z = a(N(2+))(b+). The longest time interval (15 days) and the smallest depth increment (1 m) used in the study were found to give the best K sub z estimation. (Copyright (c) 1991, ASCE.) |
| Supplementary Notes |
Pub. in Jnl. of Hydraulic Engineering, v117 n10 p1353-1369 Oct 91. St. Anthony Falls Hydraulic Laboratory Technical Paper 318, Series A. Sponsored by Environmental Research Lab.-Duluth, MN. |
| NTIS Title Notes |
Journal article. |
| Title Annotations |
Reprint: Vertical Diffusion in Small Stratified Lake: Data and Error Analysis. |
| Category Codes |
48G; 46B |
| NTIS Prices |
PC A03/MF A01 |
| Primary Description |
600/03 |
| Document Type |
NT |
| Cataloging Source |
NTIS/MT |
| Control Number |
308326184 |
| Origin |
NTIS |
| Type |
CAT |
