I would like to know how to run the EOF analysis of Walker Circulation cell. Since the Method (EOF) involves only one variable but the Walker circulation cell is obtained by using at least two variables (i.e. Zonal mean wind and the pressure vertical velocity). My problem is on how to use these two variables and make them look one ready for EOF analysis? Or is there any other way on how to analyse the EOF of Walker circulation cell? I have seen in some articles, they use meridional stream function (MSF) to run EOF of Hadley circulation. How can this be done to Walker cell?