DocumentCode :
2841224
Title :
Observation, parameterization and simulation of turbulent mixing in the Gulf of Finland, the Baltic Sea
Author :
Lilover, M.-J. ; Stips, A. -J
Author_Institution :
Marine Syst. Inst., Tallinn
fYear :
2008
fDate :
27-29 May 2008
Firstpage :
1
Lastpage :
8
Abstract :
Three time series of shear microstructure measurements (duration 13, 24 and 14 h respectively) were performed in 3 different wind forcing regimes as well as in 3 different background density stratification and current velocity shear situations at the entrance to the Gulf of Finland, in July 1998. Vertical shear of current velocity was enhanced by near-inertial waves during the first (A1) and third (A3) time series. We compared a Richardson number based parameterization and an estimation using the two equation k-epsiv turbulence closure (General Ocean Turbulence Model, GOTM) with ldquomeasuredrdquo eddy diffusivities. For two out of the three time series eddy diffusivities calculated via a Richardson number parameterization and via simulation using the k-epsiv model agreed well with the experimental data. However, in the case of relatively high current velocity shear and weak background density stratification (time series A3) both applied methods resulted in a remarkable discrepancy against the measured eddy diffusivity. On the contrary, calculations with a new parameterization scheme, which considers the internal wave kinetic energy fitted well for all three time series. Similarly the modified k-epsiv simulations which considered the internal wave energy level better matched the measured profiles.
Keywords :
geophysical fluid dynamics; ocean waves; oceanographic regions; time series; turbulence; wind; AD 1998 07; Baltic Sea; Gulf of Finland; Richardson number based parameterization; background density stratification; current velocity shear situations; general ocean turbulence model; internal wave kinetic energy; k-epsiv simulation; k-epsiv turbulence closure; near-inertial waves; shear microstructure measurements; time 13 h; time 14 h; time 24 h; time series eddy diffusivity; turbulent mixing; vertical shear; wind forcing regimes; Current measurement; Density measurement; Equations; Microstructure; Oceans; Parameter estimation; Performance evaluation; Sea measurements; Time measurement; Velocity measurement;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
US/EU-Baltic International Symposium, 2008 IEEE/OES
Conference_Location :
Tallinn
Print_ISBN :
978-1-4244-2267-8
Electronic_ISBN :
978-1-4244-2268-5
Type :
conf
DOI :
10.1109/BALTIC.2008.4625524
Filename :
4625524
Link To Document :
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