  We study the dynamics of the El Nino phenomenon using the mathematical model
of delayed-action oscillator (DAO). Topics such as the influence of the annual
cycle, global warming, stochastic influences due to weather conditions and even
off-equatorial heat-sinks can all be discussed using only modest analytical and
numerical resources. Thus the DAO allows for a pedagogical introduction to the
science of El Nino and La Nina while at the same time avoiding the need for
large-scale computing resources normally associated with much more
sophisticated coupled atmosphere-ocean general circulation models. It is an
approach which is ideally suited for student projects both at high school and
undergraduate level.
