A new function, CFU_AMO(), has been added to CFU_Rfunc.

CFU_AMO() computes the Atlantic Multidecadal Oscillation (AMO) index based on the
area-averaged North Atlantic (0-60N, 80W-0) SST anomalies minus
the global (60S-60N) SST anomalies.
See the extensive description in the header of the function.