Freely decaying weak turbulence for sea surface gravity waves
  We study numerically the generation of power laws in the framework of weak turbulence theory for surface gravity waves in deep water. Starting from a random wave field, we let the system evolve numerically according to the nonlinear Euler equations for gravity waves in infinitely deep water. In agreement with the theory of Zakharov and Filonenko, we find the formation of a power spectrum characterized by a power law of the form of $|{\bf k}|^{-2.5}$. 
M. Onorato, A. R. Osborne, D. Resio, A. Pushkarev, V. Zakharov, M.   Serio, C. Brandini