SOUTHERN OCEAN SST ANOMALY
Figure 2 illustrates the Southern Ocean SST anomalies from January 1854 to May 2005. The data is raw and smoothed with a 37-month filter. Using the smoothed data as reference, the significant rise in SST from the mid-1960s to the early 1970s is unusual, especially since it’s followed by the precipitous drop that begins January 1997, a few months before the start of the El Nino of the century.
In Figure 3, the time span has been shortened to 30+ years. It’s interesting to note that even though the trend was negative, the late 1990s rise in SST occurred before the 97/98 El Nino and that the later spike happened in September 1999, almost a year and a half after the peak of that El Nino. A Rossby wave maybe?
SOUTHERN OCEAN SST
Figures 4 and 5 are SSTs from January 1854 to May 2008 and from January 1978 to May 2008, for anyone who’s interested.
SEGMENTED SOUTHERN OCEAN SST ANOMALY
In Figure 6, I show how I divided the Southern Ocean for a view of the segmented data.
The SST anomalies of the Southern Ocean segments are then illustrated in Figure 7. The areas are identified by the letters in the legend and the map. All of the curves display a significant drop in SST in recent years. The two unusual curves are those that are east and west of the Antarctic Peninsula, curves A (blue) and B (red).
Figure 8 illustrates the SST anomalies of that portion of the Bellingshausen Sea, that area west of the Antarctic Peninsula. Its data peaked in March 2006.
Sea Surface Temperature Data is Smith and Reynolds Extended Reconstructed SST (ERSST.v2) available through the NOAA National Operational Model Archive & Distribution System (NOMADS).