  We present evidence for the nuclear ripples superimposed on the Airy
structure of the nuclear rainbow, which is similar to the meteorological
rainbow. The mechanism of the nuclear ripples is also similar to that of the
meteorological rainbow, which is caused by the interference between the
externally reflective waves and refractive waves. The nuclear ripple structure
was confirmed by analyzing the elastic angular distribution in
$^{16}$O+$^{12}$C rainbow scattering at $E_L$=115.9 MeV using the coupled
channels method by taking account of coupling to the excited states of $^{12}$C
and $^{16}$O with a double folding model derived from a density-dependent
effective nucleon-nucleon force with realistic wave functions for $^{12}$C and
$^{16}$O. The coupling to the excited states plays the role of creating the
external reflection.
