Group Analysis of Nonlinear Internal Waves in Oceans. II: The symmetries   and rotationally invariant solution
  74J30The maximal group of Lie point symmetries of a system of nonlinear equations used in geophysical fluid dynamics is presented.   The Lie algebra of this group is infinite-dimensional and involves three arbitrary functions of time. The invariant solution under the rotation and dilation is constructed. Qualitative analysis of the invariant solution is provided and the energy of this solution is presented. 
Nail H. Ibragimov, Ranis N. Ibragimov and Vladimir F. Kovalev
math-ph math.MP