By checking this box you instruct the system to subtrcat the seasonal cycle before doing the computations. For monthly data, this implies that the mean of all January values is composed and subtracted from the individual January values, the mean of all Februaries is subtracted from the February values, etc. For other time scales a similar procedure is followed. The seasonal cycle is not smoothed.

Note: for the EOF function, the Starting Month "together" option is not available.