°Empirical orthogonal function (EOF) analysis was used to study spatio-temporal variability of the Moderate Resolution
Imaging Spectroradiometer (MODIS) imagery of sea surface temperature (SST (C)) and chlorophyll (mg m-3) for the
eastern Bering Sea for May, June, July, August, September (MJJAS) for a period of 7 years (2003 - 2009). The EOF
analysis was conducted on SST and chlorophyll monthly composites that were normalized by subtracting the spatial and
temporal means with cloud, ice and land cover masked out. The SST in eastern Bering Sea showed a transition from a
warm period (2003-2005) to cooler period (2006-2009). The first 3 EOF modes of SST were retained as they explained
76.7% of the spatio-temporal variability, with the first SST EOF mode explaining 59.5% of the total variation of SST in
the study area during the study period. For the chlorophyll dataset, the first 3 EOF modes explained greater than 58.5%
of the spatio-temporal variability, with the first chlorophyll EOF explaining 28.14% of total variance in chlorophyll. The
decreasing amplitude of first SST EOF and switching from mostly positive to negative amplitude of the third chlorophyll
EOF mode in 2006 was consistent with the May SST Index, Ice Cover Index and Bering Sea Pressure Index (BSPI).
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