Finite departure from convective quasi-equilibrium: periodic cycle and discharge-recharge mechanism

A simple self–contained theory is proposed for describing life cycles of convective systems as a discharge–recharge process. A closed description is derived for the dynamics of an ensemble of convective plumes based on an energy cycle. The system consists of prognostic equations for the cloud work function and the convective kinetic energy. The system can be closed by intro ducing a functional relationship between the convective kinetic energy and the cloud–base mass flux. The behaviour of this system is considered under a bulk simplification. Previous cloud–resolving mo delling as well as bulk statistical theories for ensemble convective systems suggest that a plausible relationship would be to assume that the convective kinetic energy is linearly proportional to the cloud–base mass flux. As a result, the system reduces to a nonlinear dynamical system with two dependent variables, the cloud–base mass flux and the cloud work function. The fully nonlinear solution of this system always represents a periodic cycle regardless of the initial condition under constant large–scale forcing. Importantly, the inclusion of energy dissipation in this model does not in itself lead the system to an equilibrium.

Introduction: the legacy of Greek political thought

This Introduction offers context for the individual papers by examining the intersections and productive tensions between political thought and classical reception studies. While Plato and Aristotle have long been privileged interlocutors for political philosophers, classical reception studies has pluralised both this ancient canon and given rise to a more complex understanding of the modern heirs of ancient political thought. Similarly, the insights of studying the history of political texts and ideas across a longer tradition calls into question the fixity of concepts such as democracy, empire and political freedom. Indeed, we query the very notion of tradition by emphasising how the past has been repeatedly constructed and reconstructed in divergent modern political discourses and conversely how modern political theories and realities have been shaped and reshaped by an idea of antiquity. The Introduction closes with a brief survey of the collected papers.