High-Resolving modeling of the surface semidiurnal M₂ tide in the East-Siberian Sea

Abstract

In the framework of a high-resolving version of the 3D finite-element hydrostatic model QUODDY-4 we have simulated the fields of dynamic characteristics (amplitudes and phases of tidal elevations and barotropic tidal velocity ellipses) corresponding to the surface semidiurnal M2 tide in the no-ice East-Siberian Sea. It is shown that the obtained tidal chart has a complex structure, determined by 4 real amphidromes of left rotation which are induced by interference of counter-coming progressive Poincare waves in the southern part of the sea, 1 fake amphidrome with the center upon the Novaya Sibir Isl. and 4 small-scale amphidromes caused by interference of counter-coming Kelvin waves, from which 3 are formed in the narrow straits in the region of Bolshoy and Maly Lyahovsky Isls. and 1 near the entrance of the Chaunskaya Guba. Tidal amplitudes in the vicinity of the Novaya Sibir Isl. achieve 20–30 cm, whereas in the remaining part of the sea they are comparatively small and do not exceed 5–10 cm. Accordingly, the field of barotropic tidal velocities in the north-western part of the sea basically consists of high values (they are tens of cm/s), but in the other parts of the sea barotropic velocities are small (lower then 10 cm/s) and their field has a band structure. The fields of the averaged (over a tidal cycle) integrated in depth constituents of the barotropic tidal energy budget (namely, the barotropic tidal energy density, the advective transport and the horizontal wave flux per unit length of this energy and the rate of its dissipation due to the bottom friction) are presented. Also, a comparison of predicted tidal elevations with the mareographic level measurement data states that an estimate of their agreement may be considered as satisfactory taking into account that the tidal amplitudes in the sea as a whole are small.