ESS210B
Prof. Jin-Yi Yu
Presentations of EOF – Variance Map
qThere are several ways to present EOFs. The simplest way is to plot the values of EOF itself. This
presentation can not tell you how much the real amplitude this EOF
represents.
qOne way to represent EOF’s amplitude is to take the time series of principal components for an EOF,
normalize this time series to unit variance, and then regress it against the original data set.
qThis map has the shape of the EOF, but the amplitude actually corresponds to the amplitude in the real data with which this structure
is
associated.
qIf we have other variables, we can regress them all on the PC of one EOF and show the structure of
several variables with the correct amplitude relationship, for example, SST and surface vector wind fields can both be regressed on PCs
of SST.