History of MJO theories. MJO documented ? 1972?Holy Grail\" of Tropical Meteorology (Raymond, 2001)Madden and Julian (1972) discussion:May be associated with Tides!!Some sort of SST feedbackLarge scale waves due to stationary heatingSimilarity to Kelvin wavesMadden and Julian (1993) review:Wave response to slowly moving heat sourcePropagation faster than Kelvin wavesMoist processes (Kelvin-CISK) can slow down the speedCoupled Kelvin-Rossby model ? adequate first order model.