The multifractal characters of temperature finestructures in the equatorial western Pacific Ocean

By using part of CTD data collected at 2°S,155°E during the fall cruise of TOGA project in 1992,the multifractal characters of temperature finestructures are investigated.The absolute temperature gradients are supposed to be multifractal and their moments are computed by conventional box-counting method.It is found that these momeets have power dependence on the box size.This power dependence has two different scaling regimes,called S regime and I-regime respectively,with different scaling exponents.This is consistent with the combined effects of internal waves and mixing.Accordingly,the generalized fractal dimensions (Renyi dimension) of temperature gradients are derived.A nonlinear curve of the scaling exponents suggest a possible multifractal apptnach of the temperature shear.In fact,both regimes can be approximated by Besicovitch-Cantor model,respectively,by suitably chosen model parameters.A phenomenological model is developed on the basis of this two-regime mechanism.The model is compared with field data and Qood agreement is achieved.