Morlet wavelet
The Morlet wavelet, named after Jean Morlet, is a symmetric and periodic wavelet that results from the superposition of a sine and a Gaussian. In complex notation this can be written as:
Because of its smoothness and periodicity, the Morlet wavelet is a good choice for data that is varying continuously in time and is periodic or quasi-periodic, for example
atmospheric indices, such as the
NAO index.