  High resolution solar observations show the complex structure of the
magnetohydrodynamic (MHD) wave motion. We apply the techniques of POD and DMD
to identify the dominant MHD wave modes in a sunspot using the intensity time
series. The POD technique was used to find modes that are spatially orthogonal,
whereas the DMD technique identifies temporal orthogonality. Here we show that
the combined POD and DMD approaches can successfully identify both sausage and
kink modes in a sunspot umbra with an approximately circular cross-sectional
shape.
