Given that the reanalysis data is considered a reliable reconstruction of
the variability of the three regions of analysis, Wilkes Land, Marie Byrd
Land, and the Ross Ice Shelf, composite analysis of these regions can be
viewed as realistic depictions of these regions during ENSO events.
Throughout this section comparisons between indices have been performed,
and effort has gone to understanding whether the change in basis or change
in the time period observed is the source of differences in the observations.
As each index represents a different length of time this is possibly also a
source of discrepancy, and as such effort, has been taken to determine how
the indices agree and disagree. This work has focused on the months
September through February, as these are the months of peak ENSO activity
(Turner 2004). These months also tend to have greater agreement than other
time periods, indicating more robust ENSO events, as opposed to temporary
variations in the various indices. This analysis has been separated by
reanalysis type as they each represent different periods of time.