A Comparison of POM and ROMS for Modeling Internal Tides
in Weak Stratification
Robin Robertson and Aike Beckmann
Alfred Wegener Institut für Polar- und Meeresforschung
Bremerhaven, Germany
Internal tides were simulated using both ROMS and a modified version of
POM for two different cases of stratification and topography and the
results compared. The two cases include a two-dimensional cut over the
continental slope in the Weddell Sea and a small three-dimensional region
in the southern Weddell Sea. Identical input parameters and fields for
the two models were used, as much as possible. Although both models
showed reasonable agreement with existing observations, significant
differences were seen in the results. First, the internal tides
developed much faster with ROMS than with the modified version of POM,
~15 days as compared to ~40 days. The internal tidal fields were also
quite different in the major axis of the tidal ellipses, and both the
positive and negative rotary amplitudes. Potential causes, such as
differences in lateral and vertical mixing, vertical coordinate
stretching, etc., were investigated.