A wavelet analysis of the NOAA satellite radiometry data shows remarkable difference in the typical patterns of the sea surface temperature (SST) of the Japan Sea in autumn 1993 and spring 1994. The plumes of irregular shapes with characteristic horizontal scale of less than 30 km developed over the SST field at the beginning of the cooling season when the horizontal temperature gradients were essentially eroded. In contrast, very narrow and elongated up to 100 km streaks appeared at the beginning of the heating season when the temperature gradients were sharp. The spectral analysis of SST results in the power law behavior of k-2.0 in October and k-2.8 in May, for the scales ranging from 10 km to 100 km. This research suggests that the surface cooling in the autumn favors the enhancement of three dimensional mixing, while during the onset of heating the horizontal stirring becomes more pronounced at geostrophic turbulence scales. ¿ American Geophysical Union 1995