  The coupled atmosphere-ocean variability of the Indo-Pacific on interannual
to multidecadal timescales is investigated in a millennial control run of CCSM4
and in observations using a family of modes recovered in Part~I of this work
from unprocessed SST data through nonlinear Laplacian spectral analysis (NLSA).
It is found that ENSO and combination modes of ENSO with the annual cycle
exhibit a seasonally synchronized southward shift of equatorial surface zonal
winds and thermocline adjustment consistent with terminating El Nino and La
Nina events. The surface wind patterns associated with these modes also
generate teleconnections between the Pacific and Indian Oceans, leading to a
pattern of SST anomalies characteristic of the Indian Ocean dipole. Fundamental
and combination modes representing the tropospheric biennial oscillation (TBO)
in CCSM4 are also found to be consistent with mechanisms for seasonally
synchronized biennial variability of the Asian-Australian monsoon and Walker
circulation. On longer timescales, the leading multidecadal pattern recovered
by NLSA from Indo-Pacific SST data in CCSM4, referred to as west Pacific
multidecadal mode (WPMM), is found to significantly modulate ENSO and TBO
activity with periods of negative SST anomalies in the western tropical Pacific
favoring stronger ENSO and TBO variability. Physically, this behavior is
attributed to the fact that cold WPMM phases feature anomalous decadal
westerlies in the tropical central Pacific and easterlies in the tropical
Indian Ocean, as well as an anomalously deep thermocline in the eastern Pacific
cold tongue. Moreover, despite the relatively low SST variance explained by
this mode, the WPMM is found to correlate significantly with decadal
precipitation over Australia in CCSM4.
