Turbulence within the thermocline of two thermally stratified lakes—Lake Biwa, Japan, and Lake Kinneret, Israel—was investigated using a portable flux profiler. This instrument provided high‐resolution profiles of temperature, conductivity, and two components of velocity within a measuring volume of approximately 8 mm3. Each data profile was segmented into statistically stationary segments. A range of properties of the turbulence, including direct estimates of the vertical mass flux, were then calculated for each segment. It was found that turbulence in the thermocline was generally patchy, but within a patch, dissipation levels were relatively high. The turbulent motions were found to be fine grained with small Thorpe scales and a large skewness of the distribution of the displacement scale. This is distinct to that found in the ocean, where shear instability produces large overturns. The measurement showed that the net vertical mass flux in the thermocline was negligible and less than that predicted by Osborn (1980). This is explained by noting that the net buoyancy flux consisted of two opposing parts—a down‐gradient irreversible flux due to turbulent mixing and an up‐gradient reversible flux due to restratification—that often cancel each other within a segment. The low measured net buoyancy flux within the interior of the lakes suggested that other processes, such as gravitational adjustments and benthic boundary layer processes, should be responsible for the basin‐averaged vertical transport in these lakes.

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Since wave energy has the highest marine energy density in the coastal areas, assessment of its potential is of great importance. Furthermore, long term variation of wave power must be studied to ensure the availability of stable wave energy. In this paper, wave energy potential is assessed along the southern coasts of Iran, the Persian Gulf. For this purpose, SWAN numerical model and ECMWF wind fields were used to produce the time series of wave characteristics over 25 years from 1984 till 2008. Moreover, three points in the western, central and eastern parts of the Persian Gulf were selected and the time series of energy extracted from the modeled waves were evaluated at these points. The results show that there are both seasonal and decadal variations in the wave energy trends in all considered points due to the climate variability. There was a reduction in wave power values from 1990 to 2000 in comparison with the previous and following years. Comparison of wind speed and *REVISED Manuscript UNMARKED Click here to view linked References corresponding wave power variations indicates that a small variation in the wind speed can cause a large variation in the wave power. The seasonal oscillations lead to variation of the wave power from the lowest value in summer to the highest value in winter in all considered stations. In addition, the seasonal trend of wave power changed during the decadal variation of wave power. Directional variations of wave power were also assessed during the decadal variations and the results showed that the dominant direction of wave propagation changed in the period of 1990 to 2000 especially in the western station.

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