Anomaly time series

The scientific meaning is the deviation of a measured quantiy from its mean. Instead of the arithmetic mean, other indicators of locality may also be used, such as the numerically more robust median.

In the atmospheric sciences, the annual cycle is often used as the mean value. Famous atmospheric anomaly time series are for instance the Southern Oscillation Index[?] and the North Atlantic Oscillation[?] index. SOI is the atmospheric component of El Niño, while NAO[?] plays an important role for European weather by modification of the exit of the Atlantic storm track.