Composite Analysis
	q Compositing analysis (also called superposed epoch analysis) is to sort time series into different categories (or phases) and to compare means in these categories. q For example, how do Pacific SST evolve before, during, and after an El Nino event? In this case, there are three categories (before, during, and after) in the composite analysis. q Compositing is useful when you have many observations of some event and you are looking for responses to that event that are combined with noise from a lot of other influences. q The basic idea of the compositing analysis is that the averaging process will remove noise and keep the signals of interest. q Often compositing will reveal periodic phenomena with fixed phase that cannot be extracted from spectral analysis if the signal is small compared to the noise.