>The PDO is calculated using a 5 degree by 5 degree grid of North Pacific SST (North of 20N) anomaly data, where the SST residual and EOFs are determined for each. I don’t have the patience or time to run through all those calculations. In an attempt to illustrate what climatologists were up against when calculating the PDO, I’ve divided the Mid-Latitude (20 to 65N) North Pacific SST and SST anomalies into 10 degrees longitude bands. How someone could even consider that an El Nino like signal (the PDO) was hidden within these data sets is beyond me.
Due to the number of segments, I had to divide the data into two portions: 120E to 180 and 120W to 180. The first graph in each portion is SST. The second is SST anomaly.
One of the curves, (120 to 130E), the one farthest east of those I plotted, clearly indicated an El Nino-like oscillation, so I provided comparative graphs with NINO3.4.
120E to 180
120W to 180
ISOLATED 20 to 65N BY 120 to 130E VERSUS NINO3.4
Sea Surface Temperature Data is Smith and Reynolds Extended Reconstructed SST (ERSST.v2) available through the NOAA National Operational Model Archive & Distribution System (NOMADS).