I’ve moved to WordPress. This post can now be found at A Precursor of a Strengthening La Nina?##################
In a November 8, 2008 post Average Subsurface Temperature of the Equatorial Pacific, I discussed a dataset available from the CDC. They call the data Equatorial Upper-Ocean Heat Content Anomalies(1979-present). There they further qualify the data as “Equatorial Heat Content (average temperature in the upper 300 meters, deg C)”. I was disappointed at the time that the data hadn’t been updated since May (last data was for April, 2008), but I returned there and discovered an update that includes December 2008.
Figure 1 is a comparative graph of Average Equatorial Pacific Subsurface Temperature Anomaly and NINO3.4 SST Anomaly from January 2001 to December 2008. The longitudes of the subsurface data [180W-100W] don’t align exactly with NINO3.4 [170W-120W], but as illustrated the two datasets track reasonably well, WITH NINO3.4 LAGGING BY A MONTH OR TWO.
What caught my eye was the December 2008 Equatorial Pacific Subsurface Temperature Anomaly value. It’s presently at -1.44 deg C. If the NINO3.4 SST anomaly follows it, as it tends to do, then the La Nina would strengthen significantly. Unfortunately, tendencies help predictions, but they aren’t always true to form. NINO3.4 SST anomalies don’t always follow the Equatorial Pacific Subsurface Temperature Anomalies, as shown in Figure 2, which is a longer-term comparison. http://i40.tinypic.com/r09jjc.jpg
It’ll be interesting to see what happens.
The source of the Equatorial Pacific Subsurface Temperature Anomaly data is discussed and linked in the opening paragraph.
The Optimally Interpolated Sea Surface Temperature Data (OISST) are available through the NOAA National Operational Model Archive & Distribution System (NOMADS).