Static-Stability

Atmospheric static-stability diagnostics from Seinfeld & Pandis (2006) Ch. 16 (Meteorology of the Local Scale). Given the air temperature T and pressure p at a height z, the air temperature T_below one layer below, and the layer spacing delta_z, the component computes the potential temperature theta = T*(p_0/p)^(R_air/c_p) (Eq. 16.14), the actual temperature lapse rate dT_dz = (T - T_below)/delta_z, the potential-temperature gradient dtheta_dz = dT_dz + Gamma_d (Eqs. 16.16-16.18), and the static-stability parameter S = dtheta_dz: S > 0 stable, S = 0 neutral, S < 0 unstable. Four purely-algebraic equations, no time integration. Migrated from AtmosphericDynamics.jl@816cc391 src/local_scale_meteorology.jl:32 (`AtmosphericStability` @component).