I will discuss two fundamental systems in moist geophysical fluid dynamics: (1) The moist shallow water equations, giving rise to a theory of the MJO, and (2) A idealised system of moist convection, the 'Rainy-Benard Model'.
The tropical climate varies in a wide range of spatial and temporal scales. The tropical climate variability is more complex than the climate of the mid-latitudes because of the important role played by latent heat of condensation. The land-sea contrast theory that was proposed more than 300 years ago has been shown to be inadequate. A new paradigm based on the moist static energy budget has gained currency. I will discuss how this new paradigm provides new insight into the variability of the monsoon and the role land and oceans play in the evolution of tropical climate variability
