There is something that is baffling me. I've been doing composites for Sea-level Pressure Anomalies and exploring the SOI and moreso the Equatorial SOI. La Nina's result in +ESOI values with higher than usual pressure in the eastern Pacific and lower than usual pressure in the western Pacific. Conversely, the opposite is true during EL Nino periods.
In order to produce some illustrations to see this visually, I took the top 5 positive/negative ESOI values for December. The left is during Nina's and the right is during Nino's. I am not seeing an opposite composite. Am I interpreting something wrong? Focusing on the wrong region (I'm focusing on equator, however, it appears there may be a bit of a correlation look closer to 30N):