Log-pressure coordinate ($z=-H\log (p/p_0)$)

A log-pressure coordinate uses atmospheric pressure to define an effective height. Its density weight is proportional to $e^{-z/H}$, and its continuity equation has vertical divergence $e^{z/H}{\partial }_z(e^{-z/H}w)$. Here $H$ is the chosen pressure scale height; the coordinate is not generally identical to geometric altitude.