100 Years of Rossby Waves & Baroclinic Tides, Courtesy of the Venerable Tide Gauge

Woods Hole Oceanographic Institution, Woods Hole MA

Investigators

Abstract

Colosi OCE-0116911 A model has been developed, which separates baroclinic and barotropic contributions to tide gauge records. Cusps are generally agreed to be due to internal tides. The model assumes phase-modulated internal waves that arrive at the gauge as evanescent waves. Phase modulation results from variable phase speed due to variable thermocline characteristics caused by processes such as Rossby waves. More rapid modulation results in more cusping and zero modulation results in the internal wave being misinterpreted as the barotropic tide. The PIs propose a complete analysis of the 108-year long Honolulu record, analysis of other long records from Hawaii (there are 4 such records on the north shore that seem to be interpretable assuming a single internal tidal wave so that phase can be estimated and other processes investigated), and analysis of other long records from non-island sites, e.g. San Francisco.