Isaac Newton Institute for Mathematical Sciences

A Potential Vorticity Staircase with Semipermeable Barriers

Authors: Noboru Nakamura (University of Chicago), Da Zhu (niversity of Chicago)

Abstract

Examination of potential vorticity (PV) profiles in forced beta-plane turbulence simulations reveals sharp gradients at statistical-mean jets, but they deviate from the idealized PV staircase in some important ways. Most importantly PV is often not completely homogenized between the jet axes but maintains finite gradients.

We will first demonstrate that the PV profile is primarily governed by the permeability of the transport barriers at the jets (the idealized staircase is the impermeable limit). We will then discuss simple parameterization of PV flux across the barrier and use the resultant 1D PV equation to describe the interaction of eddy and jets.