Found the coolest paper on ARXIV. This is tangentially related to ENSO in terms of understanding how water will reach an equilibrium shape on a rotating planet.

[The dawning of the theory of equilibrium figures: a brief historical account from the 17th through the 20th century -- Giuseppe Iurato](

What's really interesting is that a Who's Who of scientists and mathematicians have worked on this problem over the centuries:
Newton, Maclauren, Jacobi, Liouville, Dirichlet, Dedekind, Riemann, Roche, Lichtenstein, Poincare, Cartan, Chandresekhar, Lagrange, Legendre, Gauss, Laplace, Lord Kelvin, Poisson, Tchebychev, Lyapunov, Markov, the other Darwin, and others.

Amazing the amount of intellectual effort that has been applied to this topic.