TABLE OF CONTENTS This ACES application predicts a tide elevation record at a specific time and locale using known amplitudes and epochs for individual harmonic constituents.
Tides are periodic in nature and are caused by the gravitational attraction of the sun and moon acting upon the rotating earth. The irregular distribution of land and water upon the planet, as well as the effects of friction, inertia, and the interactions of superimposed standing waves and progressive waves tend to complicate actual tidal motions induced by the gravitational forces. Around the year 1867, Lord Kelvin devised the method of reducing tides into constituents using harmonic analysis (Schureman, 1971). Harmonic analysis (as applied to tides) is the process by which observed tidal data at a location are reduced into a number of harmonic constituents. The quantities produced by such an analysis are known as harmonic constants and consist of amplitudes and phase relationships for each constituent. Harmonic prediction (the subject of this application) is accomplished by re-assembling the individual constituents in accordance with the appropriate astronomical relationships during the prediction period.
Harmonic tide prediction is a convenient tool for scheduling construction or maintenance work that may be affected by spring or neap tide conditions. It is also a useful tool in the application and verification of certain types of physical and hydrodynamic models where tide elevations are required either as boundary conditions or as stations for calibrating model parameters and verifying model performance.
The method is...
