Evaluation of Tides from TOPEX/Poseidon in the Bohai and Yellow Seas*

Abstract

TOPEX/Poseidon (T/P) can provide accurate tide data in the Yellow and Bohai Seas. The accuracy of T/P as a measurement tool for tides in the coastal seas can be evaluated through comparison to data from in situ pressure gauges and coastal tide stations. The effort here is concentrated on the broad continental shelf region of the Yellow and Bohai Seas. Tide coefficients are derived from five years of T/P data for M2, S2, K1, and O1 constituents. These constituents are responsible for about 80% of the tidal variability in the Yellow Sea. The T/P data are compared with two moored pressure gauges deployed along ground tracks and eight coastal tide gauges near the ground tracks. In addition, for internal consistency, the T/P data are compared at seven crossover points. Comparisons with tidal stations are quite good in the Yellow Sea, but not as good in the Bohai Sea. Comparisons of moored pressure gauges with T/P are better than coastal tide station comparisons in terms of tidal amplitude and phase. Crossover point comparisons are best in the Yellow Sea. The T/P data dropouts degrade the coefficient determination within 20 to 35 km of the coast.