Pip2u0uhh24422

Substitution of the expression h2 = 0.1(p1/p2)1/2Cuwa/|/|, as well as the relation uh = Cuu2 and values of pjp2 = 1.3 x 10~3, Cu = 1.2 x 10~3, ua = 10-15 m/s, |/| = 10"4 s-1, into (4.4.22) yields the estimate e2 « (2.5-5.5) x 10"2 cm2/s3. The typical value of e2 for the upper ocean layer (see Phillips, 1977) has the same order of magnitude. The order of e2 cannot be changed, even considering the fact that only part (40-90%) of the total momentum flux t is consumed to supply the drift current (see Kitaigorodskii, 1970). Not only the magnitude but also the vertical distribution of the turbulent energy dissipation obtained within the framework of Ekman's model of the PBL is in good agreement with experimental data. All this points to the fact that the large production and strong dissipation of the turbulent energy observed in the upper ocean layer are not necessarily connected with the existence of the diffusive turbulent energy flux from the transitional layer. Moreover, this flux can be considered as equal to zero if one assumes, following Stewart and Grant (1962), that all small-scale turbulence appearing in the transitional layer due to wind-wave breaking completely dissipates here.

However, the momentum transfer from wind to waves, and from them (due to breaking) to the drift currents does not always occur locally: such a transfer takes place only in short waves, while long waves can carry their momentum a long distance before dissipating. Because of this the curious situation where two diametrically opposed viewpoints lead to similar results in estimation of turbulent energy dissipation arises.

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