  We investigate the scalar, gravitational, and electromagnetic quasinormal
mode spectra of Schwarzschild anti-de Sitter black holes using the numerical
continued fraction method. The spectra have similar, almost linear structures.
With a few exceptions, the low overtone quasinormal modes are consistent with
previously obtained results in the literature that use other numerical
techniques. The intermediate and high overtone quasinormal modes, in comparison
to the Schwarzschild case, converge very quickly to the asymptotic formulas
previously obtained by analytic monodromy techniques. In addition, we find a
connection between the analytic asymptotic formulas and the purely imaginary
modes. In particular, these formulas can be used to predict the bifurcation of
the lowest damped electromagnetic modes. Finally, we find no high overtone
quasinormal modes with high oscillation frequency and low damping, which had
been previously predicted.
