  Ultrasound is known to enhance surface bubble growth and removal in catalytic
and microfluidic applications, yet the contributions of rectified diffusion and
microstreaming phenomena towards mass transfer remain unclear. We quantify the
effect of ultrasound on the diffusive growth of a single spherical CO$_2$
bubble growing on a substrate in supersaturated water. The time dependent
bubble size, shape, oscillation amplitude and microstreaming flow field are
resolved. We show and explain how ultrasound can enhance the diffusive growth
of surface bubbles by up to two orders of magnitude during volumetric
resonance. The proximity of the wall forces the bubble to oscillate
non-spherically, thereby generating vigorous streaming during resonance that
results in convection-dominated growth.
