Thursday, 2 May 2002: 9:15 AM
Relationships between anomalous monsoons, meridional oceanic heat transport and the Indian Ocean Dipole in the NCAR CSM
Analyses of the long term control integrations of the NCAR coupled
ocean-atmosphere Climate System Model have been conducted with the aim
of testing the relationships between the atmospheric and oceanic
variability in the Indian Ocean-Monsoon region. It is found that the
strength of the monsoon (determined by the vertical shear of the zonal
winds over South Asia in JJAS) correlates negatively and significantly
with the boreal summer meridional oceanic heat transport in the Indian
Ocean. That is, during strong boreal summer monsoon years, there is
larger quantities of southward (negative) oceanic heat transport, thus
removing heat and reducing the heat content of the north Indian Ocean.
At the same time, the sign and timing of the Indian
Ocean dipole correlates negatively with the strength of the monsoon.
That is, a strong monsoon leads to the formation of a negative dipole
(warm water in the eastern Indian Ocean, warm in the western Indian
Ocean) while a weak monsoon is associated with the opposite phase of the
dipole. It is shown that the NCAR CSM appears to corroborate theories
that suggest that the monsoon is regulated in amplitude by coupled
ocean-atmosphere processes.
Supplementary URL: