Na. Bray et al., LARGE-SCALE SEA-LEVEL, THERMOCLINE, AND WIND VARIATIONS IN THE INDONESIAN THROUGHFLOW REGION, J GEO RES-O, 101(C5), 1996, pp. 12239-12254
The Indonesian throughflow is presumed to be driven by a sea level gra
dient from the Pacific to the Indian Ocean. Deep throughflow transport
may also be driven by a steric gradient between the two basins. The s
ell level gradient, in turn, is thought to be maintained by the differ
ing wind patterns in the two basins: monsoonal in the Indian Ocean and
trades in the western equatorial Pacific. In the interaction between
sea level, wind stress, and thermocline depth as identified from histo
rical measurements, we find (1) over the Indian, Indonesian, and equat
orial Pacific basins and specifically within the throughflow region, s
ea level and thermocline seasonal variations are negatively correlated
(sea level rise corresponding to thermocline deepening) and sea level
and meridional wind stress are also correlated; (2) the expected stro
ng seasonal gradients in sea level through the eastern throughflow reg
ion (near the island of Timer) are found, though without an accompanyi
ng thermocline depth gradient; (3) seasonal convergence in baroclinic,
upper ocean throughflow transport previously identified [Meyers et al
., 1995] in the Timor Sea is associated with changes in sea level as w
ell as upper ocean dynamic height at annual period but not at semiannu
al; (4) interannual variability explains more of the sea level varianc
e in the eastern throughflow region than is explained by seasonal harm
onics; however, there does not appear to be a strong interannual signa
l in the sea level gradient to drive fluctuations in the upper ocean t
hroughflow. We hypothesize that seasonal variability in the upper laye
r throughflow and interannual variability in the deep throughflow are
the predominant results of the complex interaction of forcing mechanis
ms.