Surface acoustic energy-to-flux ratio of a pulsating sphere
= Surface acoustic energy-to-flux ratio of a pulsating sphere
At $r=a$,
$$
\frac{c_0\langle K+W\rangle}{|\langle I_r\rangle|}
=1+\frac{c_0^2}{2\omega^2a^2}.
$$
For $\omega a/c_0\gg1$, kinetic and compressional energies are equal and the field is locally radiative. For $\omega a/c_0\ll1$, reactive kinetic energy dominates and the mean radiated flux is small.