| Abstract: Part of the
heat transported poleward from the tropics by the ocean is
stored near the energetic western boundary currents. These storage
reservoirs provide a source of interannual-to-decadal climate
fluctuations through their impact on the ocean-to-atmosphere heat
fluxes. Changes in ocean heat storage result from the difference
between surface fluxes and the convergence of oceanic heat transport.
To estimate the heat budget for 26-40N, 140-180E, sea surface
temperature and subsurface temperatures are assimilated into a
one-dimensional model of the upper ocean that is forced by heat fluxes
from the NCEP Reanalysis. Heat transport convergences are inferred as
the residual of the heat budget for the period 1970-2000 using the
``unknown control" from a Kalman filter/smoother technique. The
estimates of heat transport convergence compare qualitatively with direct
estimates from a three-dimensional model that uses geostrophic currents
from the TOPEX/POSEIDON radar altimeter for 1993-1999; this period
contains the largest lateral fluxes and the largest heat loss from the
ocean in the 31-year record. The analysis of the heat budget
demonstrates that, on interannual-to-decadal time scales, the heat
storage rate in the upper ocean is better correlated with lateral heat
transport convergence than with surface fluxes. In addition heat
content and surface flux are negatively correlated, demonstrating the
dominance of oceanic feedback over atmospheric forcing. The close
relationship between heat content and surface fluxes suggests the
possibility of predicting surface flux anomalies: there is a small, but
significant skill in predicting surface flux anomalies up to one year
in advance using heat content. SST has no prediction skill.
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