Plane internal gravity wave
= Plane internal gravity wave
{title2=$e^{i(\mathbf k_h\cdot\mathbf x_h+mz-\omega t)}$}
A monochromatic <internal gravity wave> in uniform stratification has a spatially linear phase. In the nonrotating inviscid <Boussinesq approximation>, its <dispersion relation> is $\omega^2=N^2|\mathbf k_h|^2/(|\mathbf k_h|^2+m^2)$. The <wave vector> is normal to its phase planes, while the <group velocity> lies along them.