Oceanic tides over the Newfoundland and Scotian Shelves from TOPEX/POSEIDON altimetry

A modified response analysis in the form of an orthotide parametrization is used to derive major semi-diurnal and diurnal tidal constituents over the Newfoundland and Scotian Shelves from TOPEX/POSEIDON altimeter data. The orthotide formulation simultaneously solves for eight major semi-diurnal and diurnal constituents, and has an accuracy of better than similar to 1.5 cm for each constituent. Tidal elevations are derived from the altimeter data on the ascending and descending satellite ground tracks, and interpolated using the method of statistical interpolation. The semi-diurnal constituents (M(2), S-2 and N-2) compare favourably with available in-situ observations and a numerical model. The diurnals (K-1 and O-1) are not as accurate as the semi-diurnals, especially in the nearshore environment. The paper demonstrates the ability of TOPEX/POSEIDON altimetry to provide accurate tidal data over a continental shelf.