“…It results in number of papers deriving solutions for various geophysical waves, e.g. equatorially-trapped waves [5,6,7,22,25,26], waves in the presence of underlying depth-invariant currents [9,13,20,21,23,33,34,41], and a solution for trapped waves at an arbitrary latitude [16] with an instability analysis of Gerstner-like solutions in [8,29]. The mathematical importance of those solutions is presented in [24,29,31]; cf.…”