Podrobnosti záznamu

    Modelling of rapidly rotating thermal convenction using vorticity and vector potential
Údaj o odpovědnosti
    Zdeněk Mistr, Ctirad Matyska, David A. Yuen
    Matyska, Ctirad
    Mistr, Zdeněk
    Yuen, David A.
Zdrojový dokument - seriál
    Studia geophysica et geodaetica
    Vol. 46, no. 1
    p. 59-81
    10 obr., 4 tab.
    Obsahuje bibliografické odkazy
    Zkr. název ser.: Stud. geophys. geod. (Praha)
Klasifikační znak
Skupina konspektu
Předmětová skupina
    fyzika Země
    model teoretický
    planeta Země
Geografické jméno
Klíčové slovo
Abstrakt (anglicky)
   We have used a numerical scheme based on higher-order finite differences to investigate effects of adiabatic heating and viscous dissipation on 3-D rapidly rotating thermal convection in a Cartesian box with an aspect-ratio of 2x2x1. Although we omitted coupling with the magnetic field, which can play a key role in the dynamics of the Earth's core, the understanding of non-linear rotating convection including realistic thermodynamic effects is a necessary prerequisite for understanding the full complexity of the Earth's core dynamics. The system of coupled partial differential equations has been solved in terms of the principal variables vorticity omega, vector potential A and temperature T. The use of the vector potential A allows the velocity field to be calculated with one spatial differentiation in contrast to the spheroidal and toroidal function approach. The temporal evolution is governed by a coupled time-dependent system consisting of omega and T.
   The equations are discretized in all directions by using an eighth-order, variable spaced scheme. Rayleigh number Ra of 106, Taylor number Ta of 108 and a Prandtl number Pr of 1 have been employed. The dissipation number of the outer core was taken to be 0.2. A stretched grid has been employed in the vertical direction for resolving the thin shear boundary layers at the top and bottom. This vertical resolution corresponds to around 240 regularly spaced points with an eighth-order accuracy. For the regime appropriate to the Earth's outer core, the dimensionless surface temperature T0 takes a large value, around 4. This large value in the adiabatic heating/cooling term is found to cause stabilization of both the temperature and velocity fields
    Česká geologická služba
Kód přispěvatele
    ČGS (UNM)
Zdrojový formát
Datum vložení
    28. 3. 2008
Datum importu
    8. 8. 2012