Numerical Study for Baroclinic Tides Modified By an Oblique Current

Thursday, 18 December 2014
Chung an Wang, IONTU Institute of Oceanography National Taiwan University, Taipei, Taiwan and Sen Jan, NTU National Taiwan University, Taipei, Taiwan
Previous investigations suggest that when the internal waves throughout a northwest – southeast background flow, its amplitudes, propagation path, phase speed might be changed. The process occurring when internal tides meet a background geostrophic current at an angle rather than perpendicular to the current in a zonal channel is investigated using a numerical model with simplified forcing, topography and hydrographic setting. We compared numerical results of two different background conditions: (1) no background flow and (2) oblique background flow. Results indicate that the westward baroclinic energy flux tends to increase when internal tides pass through the background geostrophic flow. Different oblique angles of the background flow also cause different responses on the propagation of internal tides. The energy exchange between the internal tides and background flow is analyzed using an energy balance equation as well as the numerical results.