Tropical wave dynamics: from simple models to global simulations

Abstract: 

The tropical atmosphere is characterized by wave-like motions that span a range of scales, from mesoscale convective systems to planetary-scale disturbances like the Madden-Julian and monsoon intraseasonal oscillations. A pivotal step in major discoveries and key understanding of tropical dynamics was the foundational theory of equatorially trapped led by Matsuno in 1966. These waves are central to convectively coupled equatorial waves and MJO theories.

In this talk, I will explore key aspects of tropical wave dynamics using both reduced models based on vertical normal mode decomposition and climate model simulations. I will illustrate how equatorially trapped waves could contribute to tropical extra-tropical interactions, tropical cyclone drift, convectively coupled waves, and convective momentum transport in the dynamics of Kelvin waves and the Madden-Julian oscillation. Additionally, I will discuss how barotropic-baroclinic instability may be associated with easterly waves and tropical depressions through the interaction of baroclinic and barotropic Rossby waves. Furthermore, I will explore how eddy viscosity can facilitate interactions between tropical waves.