Low-order models of a sheared convective boundary layer

Mesoscale shallow convection (MSC) results from a complex mix of various processes: convection, vertical shear of horizontal wind, dynamical, thermal, and entrainment instabilities, effects of rotation, etc. As discussed in a recent review by Atkinson and Zhang (Reviews of Geophysics, 1996, pp. 403-431), the roles of these processes in the evolution of MSC remain unclear, thus "a gap exists in our understanding of the dynamics of the PBL".

In the talk, low-order models (LOMs) will be discussed that may help to clarify the roles and interplay of convection and shear in the dynamics of MSC. The LOMs are constructed following a general approach to the development of physically sound LOMs in the form of coupled gyrostats, outlined by Gluhovsky and Tong (Phys. Fluids, 1999, pp. 334-343). The simplest gyrostat is equivalent to the celebrated Lorenz model of Rayleigh - Benard convection.