Record Details

The Global S₁ Tide

ScholarsArchive at Oregon State University

Field Value
Title The Global S₁ Tide
Names Ray, Richard D. (creator)
Egbert, Gary D. (creator)
Date Issued 2004-08 (iso8601)
Abstract The small S₁ ocean tide is caused primarily by diurnal atmospheric pressure loading. Its excitation is therefore unlike any other diurnal tide; in particular, pressure loading is maximum near the equator where the diurnal gravitational potential is zero. The global character of the S₁ tide is here determined by numerical modeling and by analysis of Ocean Topography Experiment (TOPEX)/Poseidon satellite altimeter data. The two approaches yield reasonably consistent results. Amplitudes exceeding 1 cm in several regions are further confirmed by comparison with coastal tide gauges. Notwithstanding their excitation differences, S₁ and other diurnal tides are found to share several common features, such as relatively large amplitudes in the Arabian Sea, the Labrador Sea, the Sea of Okhotsk, and the Gulf of Alaska. The most noticeable difference is the lack of an S₁ Antarctic Kelvin wave. These similarities and differences can be explained in terms of the coherences between near-diurnal oceanic normal modes and the underlying tidal forcings. Whereas gravitational diurnal tidal forces excite primarily a 28-h Antarctic–Pacific mode, the S₁ air tide excites several other near-diurnal modes, none of which has large amplitudes near Antarctica.
Genre Article
Identifier Ray, Richard D., Gary D. Egbert, 2004: The Global S1 Tide. Journal of Physical Oceanography, 34, 1922–1935.

© Western Waters Digital Library - GWLA member projects - Designed by the J. Willard Marriott Library - Hosted by Oregon State University Libraries and Press