I want to calculate the Madden-Julian Oscillation (MJO) phase by myself using Real-time Multivariate MJO series 1 (RMM1) and 2 (RMM2) from a data file.
The formula for doing so is:
$MJO phase = \arctan\left(\frac{RMM2}{RMM1}\right)$
but that doesn’t get me to an MJO phase of 1 to 8.
I’ve trawled the web extensively but can’t find a solution.
Thanks in advance.