Contribution of β-Effect to the Formation of Sea Level and Current Fields in the Baltic Sea

摘要

The contribution of the combined effect of the Earth's sphericity and rotation (β-effect) to the formation of the sea level and current fields in the Baltic Sea is estimated on the basis of numerical experiments by means of a hydrodynamic model and statistical analysis of the results of these experiments. It is found that the β-effect exerts a marked influence on the evolution of the quasi-permanent circulation of the Baltic Sea. In the synoptic range of space-time scales, its contribution to the total dispersion of the sea level and currents does not exceed 5-6%, though in individual regions of the sea very intensive pulse-type disturbances in the currents are produced episodically as a result of the β-effect; note that these disturbances are not apparent in the sea level fluctuations. These disturbances are identified as Rossby solitons or rapidly damping modes of Rossby progressive standing waves peculiar to closed basins.