Kinematic characteristics of internal wave field in the Gotland deep of the Baltic Sea

The region of the Gotland Basin where the intrusive lenses has been observed is discussed. Using the field data the temperature and salinity profiles were processed for the Brunt-Vaisala frequency profiles and the solving of eigenfunction problem for the first mode. The theory of the Korteweg-de Vries equation is given for description of the long internal wave propagation. The obtained eigenfunctions were used for calculation of the nonlinear and dispersion coefficients of the Korteweg-de Vries equation. The contour maps for speed of internal wave, nonlinear and dispersion parameters are constructed. It is shown that dispersion and phase speed are depended mainly from the basin depth and nonlinearity is defined by some factors such as the horizon of the picnocline, the maximum of buyouancy frequency and others. It is shown that the nonlinear parameter changes the sign on the depths 160-200m. The intrusive lens seems to influence on the kinematic characteristics of internal waves very weakly.