The life span of atmospheric anomalies depends on
whether they are coupled, and on the type of interaction
they have, with the underlying ocean anomalies.
The dynamical rule applied to the reanalysis data gives
results consistent with previous studies and with the lag-
correlation between 850mb RV and SST: Ocean drives the
atmosphere in the tropics and the reverse occurs in the
The AMIP run from the NCEP shows fewer long lasting
anomalies than observed. This error is associated with
ignoring the feedback effect of the atmosphere on the ocean.