Principal Components Analysis (PCA) in S-Mode (correlation between temporal series) was performed on
sea ice monthly anomalies, in order to investigate which are the main temporal patterns, where are the homogenous
areas located and how are they related to the sea surface temperature (SST). This analysis provides 9 patterns (4 in the
Amundsen and Bellingshausen Seas and 5 in the Weddell Sea) that represent the most important temporal features that
dominated sea ice concentration anomalies (SICA) variability in the Weddell, Amundsen and Bellingshausen Seas over
the 1979-2000 period. Monthly Polar Gridded Sea Ice Concentrations data set derived from satellite information
generated by NASA Team algorithm and acquired from the National Snow and Ice Data Center (NSIDC) were used.
Monthly means SST are provided by the National Center for Environmental Prediction reanalysis. The first temporal
pattern series obtained by PCA has its homogeneous area located at the external region of the Weddell and
Bellingshausen Seas and Drake Passage, mostly north of 60°S. The second region is centered in 30°W and located at the
southeast of the Weddell. The third area is localized east of 30°W and north of 60°S. South of the first area, the fourth
PC series has its homogenous region, between 30° and 60°W. The last area is centered at 0° W and south of 60°S.
Correlation charts between the five Principal Components series and SST were performed. Positive correlations over the
Tropical Pacific Ocean were found for the five PCs when SST series preceded SICA PC series. The sign of the
correlation could relate the occurrence of an El Niño/Southern Oscillation (ENSO) warm (cold) event with posterior
positive (negative) anomalies of sea ice concentration over the Weddell Sea.
