Global Ocean Tides. Part I. A Detailed Hydrodynamical Interpolation Model.
Abstract
A new hydrodynamical interpolation technique has been developed and tested to construct a model of global ocean tides with the support of empirical tidal constants collected around the world. The discrete tide model features a 1 deg by 1 deg graded grid system in connection with a hydrodynamically defined bathymetry. The Laplace tidal equations are augmented by turbulent friction terms with novel mesh-area (latitude and depth) dependent eddy-viscosity and bottom-friction coefficients. The well-known astronomical tide-generating forces are modified by effects due to solid earth tides and ocean-tidal loading. New averaged finite differences in time are used to enhance stability characteritics and to facilitate the hydrodynamical interpolation of empirical data. This unique interpolation is accomplished by a controlled adjustment of the bottom-friction coefficient and by redefining a more physical shoreline. Extensive computer experiments were conducted to study the characteristics of the novel friction laws and hydrodynamical interpolation methods. The computed M2 tide data along with all (specially labeled) empirical constants are tabulated in map form for four typical 30 by 50 deg ocean areas. A complete tabulation and discussion of the computed M2 tide will be published in Part II of this report. It is estimated that the tabulated tidal charts permit a prediction of the M2-tide elevation of the ocean surface over the geoidal level with an accuracy of better than 5 cm anywhere in the open ocean and with somewhat less accuracy near rough shorelines.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1978
- Accession Number
- ADA060913
Entities
People
- E. W. Schwiderski
Organizations
- Naval Surface Warfare Center Dahlgren Division