Eady

Eady refers primarily to a classical concept in meteorology known as the Eady model, a simplified linear theory of baroclinic instability in a midlatitude atmosphere. Introduced by Eady in 1949, the model analyzes small disturbances in a basic state that features uniform vertical shear and constant static stability, bounded by rigid lids at the top and bottom. By linearizing the governing equations around this basic state, it yields a dispersion relation that can be used to determine growth rates and the most unstable horizontal wavelengths.

The Eady model is used as an educational and theoretical tool to illustrate how energy is transferred from the mean flow to perturbations, leading to the development of atmospheric cyclones. It helps clarify how vertical shear and stratification influence instability while providing analytic insight that more complex models may obscure. Although highly idealized, the model captures essential physics of baroclinic growth and serves as a reference point for understanding midlatitude dynamics and cyclone formation.

Beyond its meteorological application, the name Eady also exists as a surname in English-speaking regions. In scientific and educational contexts, the term “Eady” is often encountered in discussions of atmospheric stability, linear instability analysis, and the historical development of theories of midlatitude weather systems.