Ocean tides, part II: A hydrodynamical interpolation model
Title:
Ocean tides, part II: A hydrodynamical interpolation model
Author:
Schwiderski, Ernst W.
Appeared in:
Marine geodesy
Paging:
Volume 3 (1980) nr. 1-4 pages 219-255
Year:
1980
Contents:
The strictly mathematical ocean tide model developed in Part I of this paper is modified in order to include realistic hydrodynamical barrier effects of narrow ocean ridges and other large bottom irregularities. This modification begins with a hydrodynamical redefinition of the ocean bathymetry at over 3,000 grid points, increasing simultaneously the depth data range to: 10m ? 7,000m. In a second step a unique hydrodynamical interpolation technique is developed that incorporates into the model over 2,000 empirical tide data collected around the world at continental and island stations. This interpolation is accomplished by a controlled cell-wise adjustment of the bottom friction coefficient and by allowing a monitored in- or out-flow across the mathematical ocean boundary and so, 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° ocean areas. 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. With the forthcoming construction of the lesser S2, N2, and K2; K1; O1, P1, and Q1; and Mf, Mm, and Ssa tidal constituents, the total tide-prediction error can be kept below the 10-cm bound posed by applied researchers of today.
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