# Cyclogenesis based on Petterson eqaution

## Peterssen equation
1. Target
Finding the upper-lower level interactoin during cyclogenesis.

2. Equation
$$
\frac{\partial \zeta_l}{\partial t} = -\vec{v}\cdot \nabla\zeta_{500\;mb}-\kappa\nabla^2(\overline{-\vec{v}\cdot\nabla T}+\overline{(\Gamma_d-\Gamma)\omega}+\overline{q}/C_p)
$$

In this equation, if:
$\frac{\partial \zeta_l}{\partial t}>0$: cyclogenesis

3.