Abstract
In this study, the method of numerical mixing analysis is presented for three-dimensional ocean models with general vertical coordinates. Numerical mixing of a scalar is defined as the decay of the square of the scalar due to the three-dimensional advection discretisation. It is shown that for any advection scheme the numerical mixing can be calculated as the difference between the advected square of the scalar and the square of the advected tracer, divided by the time step. Special emphasis on directional-split advection schemes is made. It is shown that for those directional-split schemes the numerical analysis method is exact only when the involved advection of the square of the scalar is carried out individually for each split step. As applications, an idealised meso-scale eddy test scenario without any explicit mixing is calculated. It is shown that only for high-order advection schemes for the scalar (salinity in that case) and the momentum, a physically reasonable solution is obtained. Finally, the method is demonstrated for a fully realistic application to the dynamics of the Western Baltic Sea. Here it becomes clear that physical and numerical mixing depend on each others (increased physical mixing leads to decreased numerical mixing) with the dynamically most relevant mixing being the effective mixing, i.e., the sum of the physical and the numerical mixing.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
Burchard, H.: Quantitative analysis of numerically induced mixing and dissipation in discretisations of shallow water equations. Int. J. Geomath. 3, 51–65 (2012)
Burchard, H., Bolding, K.: GETM – a general estuarine transport model. Scientific Documentation. Tech. Rep. No. EUR 20253 EN, European Commission 29, 157 p. (2002)
Burchard, H., Bolding, K., Villarreal, M.R.: Three-dimensional modelling of estuarine turbidity maxima in a tidal estuary. Ocean Dyn. 54, 250–265 (2004)
Burchard, H., Janssen, F., Bolding, K., Umlauf, L., Rennau, H.: Model simulations of dense bottom currents in the Western Baltic Sea. Cont. Shelf Res. 29, 205–220 (2009)
Burchard, H., Lass, H.U., Mohrholz, V., Umlauf, L., Sellschopp, J., Fiekas, V., Bolding, K., Arneborg, L.: Dynamics of medium-intensity dense water plumes in the Arkona Sea, Western Baltic Sea. Ocean Dyn. 55, 391–402 (2005)
Burchard, H., Petersen, O.: Hybridisation between σ and z coordinates for improving the internal pressure gradient calculation in marine models with steep bottom slopes. Int. J. Numer. Meth. Fluids 25, 1003–1023 (1997)
Burchard, H., Rennau, H.: Comparative quantification of physically and numerically induced mixing in ocean models. Ocean Model. 20, 293–311 (2008)
Fennel, W., Radtke, H., Schmidt, M., Neumann, T.: Transient upwelling in the central Baltic Sea. Cont. Shelf Res. 30, 2015–2026 (2010)
Getzlaff, J., Nurser, G., Oschlies, A.: Diagnostics of diapycnal diffusivity in z-level ocean models. part I: 1-Dimensional case studies. Ocean Model. 35, 173–186 (2010)
Getzlaff, J., Nurser, G., Oschlies, A.: Diagnostics of diapycnal diffusion in z-level ocean models. Part II: 1-Dimensional case studies. Ocean Model. 45-46, 27–36 (2012)
Gräwe, U., Burchard, H.: Storm surges in the Western Baltic Sea: the present and a possible future. Clim. Dyn. (in print, 2012)
Griffiths, R.W., Linden, P.F.: The stability of vortices in a rotating, stratified fluid. J. Fluid Mech. 105, 283–316 (1981)
Hofmeister, R., Beckers, J.-M., Burchard, H.: Realistic modelling of the major inflows into the central Baltic Sea in 2003 using terrain-following coordinates. Ocean Model. 39, 233–247 (2011)
Hofmeister, R., Burchard, H., Beckers, J.-M.: Non-uniform adaptive vertical grids for 3D numerical ocean models. Ocean Model. 33, 70–86 (2010)
Leonard, B.P.: The Ultimate conservative difference scheme applied to unsteady one-dimensional advection. Comput. Meth. Appl. Mech. Eng. 88, 17–74 (1991)
Pietrzak, J.: The use of TVD limiters for forward-in-time upstream-biased advection schemes in ocean modeling. Mon. Weather Rev. 126, 812–830 (1998)
Rennau, H., Burchard, H.: Quantitative analysis of numerically induced mixing in a coastal model application. Ocean Dyn. 59, 671–687 (2009)
Riemenscheider, U., Legg, S.: Regional simulations of the Faroe Bank Channel overflow in a level model. Ocean Model. 17, 93–122 (2007)
Roe, P.L.: Some contributions to the modeling of discontinuous flows. Lect. Notes Appl. Math. 22, 163–193 (1985)
Sellschopp, J., Arneborg, L., Knoll, M., Fiekas, V., Gerdes, F., Burchard, H., Lass, H.U., Mohrholz, V., Umlauf, L.: Direct observations of a medium-intensity inflow into the Baltic Sea. Cont. Shelf Res. 26, 2393–2414 (2006)
Smagorinsky, J.: General circulation experiments with the primitive equations. Mon. Weather Rev. 91, 99–164 (1963)
Strang, G.: On the construction and comparison of difference schemes. SIAM J. Num. Anal. 5, 506–517 (1968)
Tartinville, B., Deleersnijder, E., Lazure, P., Proctor, R., Ruddick, K.G., Uittenbogaard, R.E.: A coastal ocean model comparison study for a three-dimensional idealised test case. App. Math. Model. 22, 165–182 (1998)
Umlauf, L., Arneborg, L.: Dynamics of rotating shallow gravity currents passing through a channel. Part I: Observation of transverse structure. J. Phys. Oceanogr. 39, 2385–2401 (2009)
Umlauf, L., Arneborg, L., Burchard, H., Fiekas, V., Lass, H.U., Mohrholz, V., Prandke, H.: The transverse structure of turbulence in a rotating gravity current. Geophys. Res. Lett. 34, L08601 (2007), doi:10.1029/2007GL029521
Umlauf, L., Burchard, H.: Second-order turbulence models for geophysical boundary layers. A review of recent work. Cont. Shelf Res. 25, 795–827 (2005)
van der Lee, E.M., Umlauf, L.: Internal-wave mixing in the Baltic Sea: Near-inertial waves in the absence of tides. J. Geophys. Res. 116 (2011), doi:10.1029/2011JC007072
van Leer, B.: Toward the ultimate conservative difference scheme. V: A second order sequel to Godunov’s method. J. Comput. Phys. 32, 101–136 (1979)
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2013 Springer-Verlag Berlin Heidelberg
About this chapter
Cite this chapter
Burchard, H., Gräwe, U. (2013). Quantification of Numerical and Physical Mixing in Coastal Ocean Model Applications. In: Ansorge, R., Bijl, H., Meister, A., Sonar, T. (eds) Recent Developments in the Numerics of Nonlinear Hyperbolic Conservation Laws. Notes on Numerical Fluid Mechanics and Multidisciplinary Design, vol 120. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-33221-0_6
Download citation
DOI: https://doi.org/10.1007/978-3-642-33221-0_6
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-642-33220-3
Online ISBN: 978-3-642-33221-0
eBook Packages: EngineeringEngineering (R0)