Idealized investigation of mechanisms linking tropical cyclone eye wall vorticity structure to interactions of the inflow and outflow with the environment

Recently Rappin, Morgan and Tripoli (2009) studied mechanisms of how the interaction of hurricane outflow with a jet can impact the internal structure of a tropical cyclone. Results indicated a very strong role of environmental forcing through its impacts on outflow resistance. Here, a series of idealized simulations of a tropical cyclone are performed to study how particular environmental interactions create, maintain or alter the vortical structure of the eye wall and the dynamic and thermodynamic structure of the eye itself. Of particular interest is the manner in which the storm vortical structure interacts with the environment while under the constraints of vorticity and moist entropy conservation. Just as for the general circulation of the planet, the tropical cyclone flow features an overworld, isolated from surface effects that interacts with an underworld, that is intimately connected to surface fluxes. In this sense, the outflow and lower eye wall are underworld features while the upper eye is an overworld feature isolated from the surface. For this study, a physically well-constrained dynamical model is employed and vorticity is viewed as a three-dimensional vector evolving in the two separate worlds and coming together to create the dynamics that we see. At the presentation, these interacting features will be defined and their sensitivity to environmental structure will be discussed.