Characterization of Principal Tidal Constituents in the Northern Arabian (Persian) Gulf

Abstract:

For marginal seas open to primary ocean basins, and coastal oceans, it is necessary to prescribe the tidal forcing on the boundaries open to the ocean basin. In many cases, it is this forcing that is more important than the astronomical forcing. The Arabian Gulf is such an example. Here we present results from analysis of sea-level time series collected at four stations (Khiran, Fintas, Salmiya, Subiya; see Figure) along the Kuwaiti coast and currents collected from a bottom mounted acoustic Doppler current profiler (ADCP) at a shelf station (Qaruh). Tides are mixed semi-diurnal with more than 90% of the total tidal amplitude variance explained by the K1, O1, M2, and S2 constituents at all four stations. The K1 and M2 constituents alone contribute >75% variance at each station. A clear pattern of increase of the total tide amplitude along the coast, from south (up to ~1 m amplitude) to north (up to ~2 m amplitude), was observed with the M2 tide contributing from 33% of the total variance at the southern station to 65% at the northern station. Analysis of ADCP current profiles indicates that the U (East-West) and V (North-South) tidal current components reach amplitudes of 0.2 and 0.5 m/s, respectively, throughout the water column. About 90% of the current variance could be explained by the K1, O1, M2, and S2 constituents. Initial results of comparison to three tide prediction models suggest that the predictions that best fit our observations are produced by UK Admiralty TotalTide, then by Xtide, and lastly by OSU's Tidal Prediction Software programs.