Observed frequencies of the ﹩n=0﹩ (solid lines), 1 (dashed line), 2 (dotted line), and 3 (dot‐dashed line) modes as a function of B. We plot ﹩l=2﹩, 4, and 7 for ﹩n=0﹩. The ﹩n> 0﹩ modes are independent of l (at least at these low l‐values). Frequencies with ﹩B> B_{\mathrm{crit}\,}﹩ (shaded region) cannot be trusted if the magnetic field has a nonvertical component. Note that at low B, avoided crossings occur between the trapped ocean Alfvén waves and shear waves.