Abstract: | On the basis of well-known solutions, we analyse an internal surge, i.e. a sharp step-like variation of the pycnocline depth in a shallow basin. According to results obtained, in those cases where the pycnocline is situated approximately at mid-depth of the basin, the surge may have the form of a steadily moving non-linear wave (kink) governed by the combined Korteweg-de Vries equation with quadratic and cubic non-linearities. The vertical velocity component in such a wave has the form of a pulse and represents a soliton. Estimates of surge parameters obtained from real hydrologic data are in good agreement with the experimentally measured data.Translated by Vladimir A. Puchkin. |