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Large-Eddy Simulations (LES) have shown the effects of ocean surface gravity waves in enhancing the ocean boundary layer mixing through Langmuir turbulence. Neglecting this Langmuir mixing process may contribute to the common shallow bias in mixed layer depth in regions of the Southern Ocean and the Northern Atlantic in most state-of-the-art climate models. In this study, a third generation wave model, WAVEWATCH III, has been incorporated as a component of the Community Earth System Model, version 1.2 (CESM1.2).

The recent discovery of localised intense magnetic fields in the solar photosphere is one of the major surprises of the past few years. Here we consider the theoretical nature of small amplitude motions in such an intense magnetic flux tube, within which the field strength may reach 2 kG. We give a systematic derivation of the governing 'expansion' equations for a vertical, slender tube, taking into account the dependence upon height of the buoyancy, compressibility and magnetic forces. Several special cases (e.g., the isothermal atmosphere) are considered as well as a more realistic, non-isothermal, solar atmosphere. The expansion procedure is shown to give good results in the special case of a uniform basic-state (in which gravity is negligible) and for which a more exact treatment is possible.The form of both pressure and velocity perturbations within the tube is discussed. The nature of pressure perturbations depends upon a critical 'transition' frequency, top, which in turn is dependent upon depth, field strength, pressure and density in the basic (unperturbed) state of the tube. At a given depth in the tube pressure oscillations are possible only for frequencies greater than tot,; for frequencies below top exponentially decaying (evanescent) pressure modes occur. In a similar fashion the nature of motions within the flux tube depends upon a 'transition' frequency, to,. At a giver~ depth within the tube vertically propagating waves are possible only for frequencies greater than too ; for frequencies below too exponentially decaying (evanscent) motions occur. The dependence of both tot, and to~ on depth is determined for each of the special cases, and for a realistic solar atmosphere. It is found that the use of an isothermal atmosphere, instead of a more realistic temperature profile, may well give misleading results.For the solar atmosphere it is found that toy is zero at about 12 km above optical depth ~'5o0o = 1, thereafter rising to a maximum of 0.04 s -1 at some 600 km above 75o0o = 1. Below 750o0 = 1, in the convection zone, toy has a maximum of 0.013 s -I. The transition frequency, top, for the pressure perturbations, is peaked at 0.1 s -1 just below zsooo = 1, falling to a minimum of 0.02 s -1 at about one scale-height deeper in the tube Solar Physics 56 (1978) 5-35. All Rights Reserved Copyright @~ 1978 by D. Reidel Publishing Company, Dordrecht, Holland * Note that the z-scale refers to the surrounding photosphere, not to the tube's interior. VERTICAL MOTIONS IN AN INTENSE MAGNETIC FLUX TUBE

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