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Title: Diapycnal Mixing in the Thermocline of Lakes: Estimations by Different Methods Authored by: Etemad Shahidi, A. and Imberger, J. Abstract:
Abstract. In order to evaluate the performance of different methods for estimation of
the vertical eddy diffusivity in thermally stratified lakes, two field studies were conducted in Lake Biwa, Japan and Lake Kinneret, Israel. Lake Biwa experienced three typhoons during the campaign while Lake Kinneret experienced high winds in the afternoons. Microstructure profiles were collected by a portable flux profiler (PFP) during calm and disturbed periods. Then, the vertical eddy diffusivity was estimated by three indirect methods. The estimated vertical eddy diffusivities varied more than one order of magnitude,
from 4.7
× 10âˆ'
7
to 7.7
× 10âˆ'
6
m2 sâˆ'1 . The comparison of results with previous buoyancy
flux measurements and scaling arguments showed that the Dillonâ€"Park's method is not
appropriate and Osbornâ€"Cox method performs better than Osborn method in the stud-
ied case. Furthermore, the low value of vertical eddy diffusivity within the thermocline
suggests that within the thermocline of these lakes, diffusive vertical transport can be
neglected.
Reference: Etemad Shahidi, A. and Imberger, J., 2006, Diapycnal Mixing in the Thermocline of Lakes: Estimations by Different Methods, 6 (3): 227 - 240 Keywords: Dillon-Park method, Osborn method, Osborn-Cox method, turbulent mixing vertical eddy diffusivity |
