Hurricane inner-core PV mixing: forced simulations using a shallow water model

Dynamic instability of the hurricane eyewall hollow potential vorticity (PV) tower and subsequent PV mixing between the eyewall and eye has been shown to be an important process for structural and intensity variability in observations, as well as in barotropic and three-dimensional idealized primitive equation model simulations. In recently published work on the latter, the PV core in full-physics simulations was explained to a large degree by a simpler dry primitive equation model in an unforced, adiabatic, framework. In a forced context, Rozoff et al. (2009) (J. Atmos. Sci.) has examined the instability and PV mixing process with the effects of diabatic heating parameterized as a forcing term to the nondivergent barotropic vorticity equation. Building on that work, here we examined the hurricane inner-core PV mixing process in the context of a forced shallow water model. Diabatic heating is parameterized by an annular mass sink, and simulations are conducted to assess the vortex structural and intensity change in the presence of this forcing.