A Relationship Between Baroclinic Tidal and Wave Horizontal Spectral Energy and Stratification on the Australian Continental Shelf

<title>Abstract</title> <p> In order to investigate the seasonal dependence of the baroclinic kinetic energy, temperature and velocity data from sixteen moorings off Australia were analyzed. The sites ranged in latitude from ~12 ^o S to 38 ^o S and each had time series at least 4 years in length. The time series for each site were divided into 10-day segments to provide upper ocean to bottom temperature differences and baroclinic kinetic energy values for each segment. These values were then used to develop general relationships between the upper ocean to bottom temperature difference and the horizontal internal wave energy for five different frequency bands: diurnal, semidiurnal, harmonic (3-10 cpd), high frequency ( <underline>&gt;</underline> 10 cpd), and all frequencies (0.167-12 cpd). These relationships followed a power law, E _H = E _BT B dT ^A where E _H represents the horizontal baroclinic spectral energy, E _BT is the horizontal barotropic spectral energy, dT is the upper ocean to bottom temperature difference, and A and B are latitude dependent coefficients. However, investigation of 12 additional sites showed no relationship between the upper ocean to temperature difference and the baroclinic energy and the velocities were essentially barotropic. Relationships were present only if the upper ocean to bottom temperature difference exceeded 4 ^o C and the water depth was at least 60 m. These relationships can be useful in predicting the horizontal baroclinic energy fields for these frequency ranges without deploying and maintaining expensive velocity observations. The relationships can also be used to estimate the horizontal baroclinic energy available for mixing in models. </p>