These findings indicate that the IO SST variability plays an important role in the
ENSO-induced anomalies in the Indian monsoon region. A strong SST dipole with
positive anomalies in the east and negative in the west may suppress the effect of ENSO
on the Indian monsoon region. This result is consistent with recent observational
evidence reported by Krishnamurthy and Shukla (2008) in which they showed that in
1997, when the JJAS seasonal mean monsoon was near normal despite being an El Niño
year, the IO dipole signal acted to nullify the impact of the ENSO. Recently, Janakiraman
et al. (2011) pointed out the existence of unrealistic IO dipole events in their CFS
hindcast run. Lau and Nath (2000) also noted that in a coupled system, the ENSOinduced
SST anomalies in the IO could act to reduce the impact of the remote signal.