• Hawaii;
  • adjoint;
  • internal tides;
  • tidal conversion

Energy from the barotropic tide is transferred into the baroclinic tide over topographic gradients, which provides a mechanism for the ocean boundaries to communicate with the deep ocean, to close energy budgets, and as a source of flux affecting nutrient supply and larval transport. Understanding the temporal variability of the conversion from barotropic to baroclinic tides is critical to our understanding of these processes. Using a numerical model and its adjoint, we examine the sensitivity of tidal conversion at Kaena Ridge in Hawaii. We find a sensitivity to changes in the upper ocean due to a phase difference between the pressure anomaly and tidal velocity caused by internal waves generated on the opposite slope of the ridge; however, we also find that conversion is equally as sensitive to local, deep stratification changes.