  In real-world geophysical applications (such as predicting the climate
change), the reduced models of real-world complex multiscale dynamics are used
to predict the response of the actual multiscale climate to changes in various
global atmospheric and oceanic parameters. However, while a reduced model may
be adjusted to match a particular dynamical regime of a multiscale process, it
is unclear why it should respond to external perturbations in the same way as
the underlying multiscale process itself. In the current work, the authors
study the statistical behavior of a reduced model of the linearly coupled
multiscale Lorenz 96 system in the vicinity of a chosen dynamical regime by
perturbing the reduced model via a set of forcing parameters and observing the
response of the reduced model to these external perturbations. Comparisons are
made to the response of the underlying multiscale dynamics to the same set of
perturbations. Additionally, practical viability of linear response
approximation via the Fluctuation-Dissipation theorem is studied for the
reduced model.
