Fundamental Equations Governing Cloud Processes

This chapter presents equations that govern kinematic and thermodynamic processes in clouds and cloud systems. First a set of state properties are presented, and then equations for conservation of mass, momentum, and energy are provided. Some predictive equations that are commonly used in numerical weather prediction models are also presented and assumptions made for some equation sets are discussed. Conserved variables for moist processes are evaluated in detail with special attention paid to the underlying approximations and assumptions (e.g., reversible or pseudoadiabatic thermodynamics). The chapter concludes by reviewing some concepts that arise from application of the governing equations, including: buoyancy, static stability, lapse rates, and convective available potential energy.