DEBOT model

(David Einšpigel's Barotropic Ocean Tide model)


This page is about the DEBOT model, a global barotropic ocean model, which I have been developing since 2010.
The model was first described in my diploma thesis (Einšpigel, 2012), however many changes and improvements have been implemented since then. The model has now two modes: DEBOT-h, a purely hydrodynamical mode, and DEBOT-a, an assimilative mode. The model is described in two papers: Einšpigel and Martinec (2015, 2016).

Characteristic of the model

  • The governing equations are the shallow-water equation in geographical coordinates.
  • Time-domain model. The time-stepping scheme is a generalized forward-backward scheme with a combined Adams-Bashforth and Adams-Moulton step (Shchepetkin and McWilliams, 2008).
  • Simulations of global ocean circulation except the polar areas.
  • Real bathymetry data are obtained from 1 arc-minute models ETOPO1 (Amante & Eakins, 2009) or GEBCO (IOC et al., 2003), a spatial resolution is defined by a user.
  • The lunisolar tidal forcing implemented, the ephemerides of the Moon and the Sun are computed by the set of subroutines NOVAS F3.1 (Kaplan et al., 2011).
  • Assimilative version of DEBOT is constrained by data from DTU10 model or OSU12 model
  • The bottom friction, turbulent viscosity, scalar approximation of the self-attraction and loading and internal tide drag are implemented.
  • The code is written in the free-format Fortran and parallelized using OpenMP, CPP switches are used for defining model options.

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Results

10 days simulation of global ocean circulation (20' resolution) forced by the lunisolar tidal potential. Color scale denotes the elevation in meters.

  • Amplitudes and Greenwich phase lags of the surface elevation and zonal and meridional transports for eight major tides: Q1, O1, P1, K1, N2, M2, S2, K2.
  • Absolute vector differences of all three variables between DEBOT-h and DEBOT-a and also between DEBOT-a and TPXO for reference: Q1, O1, P1, K1, N2, M2, S2, K2.
  • Surface elevation amplitudes and Greenwich phase lags of selected minor tides and compound tides for DEBOT-a and FES2012 for reference and the absolute value differences between DEBOT-a and FES2012: Ssa, Mm, Mf, Mtm, J1, ε2, 2N2, μ2, ν2, λ2, L2, T2, R2, M3, N4, MN4, M4, MS4, M6, M8.
  • References

    • Amante, C. & Eakins, B. W., 2009: ETOPO1 1 Arc-Minute Global Relief Model: Procedures, Data Sources and Analysis. NOAA Technical Memorandum NESDIS NGDC-24, 19 pp.
    • Einšpigel, D., 2012: Barotropic ocean tide model. Master thesis, Charles University in Prague.
    • Einšpigel, D. & Martinec, Z., 2015: A new derivation of the shallow water equations in geographical coordinates and their application to the global barotropic ocean model (the DEBOT model). Ocean Modelling, 92, 85–100. DOI: 10.1016/j.ocemod.2015.05.006
    • Einšpigel, D. & Martinec, Z., 2016: Time-domain modelling of global ocean tides generated by the full lunisolar potential. Accepted to Ocean Dynamics. DOI: 10.1007/s10236-016-1016-1.
    • IOC, IHO, BODC, 2003: Centenary edition of the GEBCO digital atlas. Published on CD-ROM on behalf of the Intergovernmental Oceanographic Commission and the International Hydrographic Organization as part of the General Bathymetric Chart of the Oceans.
    • Kaplan, G., Bartlett, J., Monet, A., Bangert, J. & Puatua, W., 2011: User's Guide to NOVAS Version F3.1. Washington, DC: USNO.
    • Shchepetkin, A. F. & McWilliams, J. C., 2008: Computational kernel algorithms for fine-scale, multi-process, long-time oceanic simulations. In Handbook of Numerical Analysis: Computational Methods for the Ocean and the Atmosphere, Elsevier Science, ISBN: 978-0-444-51893-4.