Abstract
A theoretical model is presented that describes deepening of a surface mixed layer under the action of wind. The model is an extention of DIM (Dynamic Instability Model) which is applicable for the situation where turbulence produced by wind-induced shear flow rather than water stirring by wind itself controls the entrainment process. Comparative considerations of existing results lead to an idea that the meanings of self-similarity must be followed up for a reasonable modeling. Present study therefore adopts some assumptions on self-similarity not only of density and velocity profiles but also of energetic balance and of mass and momentum transport. Consistency of these assumptions is described through a simple imaginary mixing model associated with K-H instability mixing. The resulted model, including no unknown parameter, successfully predicts the entrainment rate observed by authors in Lake Kasumigaura.
