Altimeter data from the Geosat Exact Repeat Mission (ERM) are analyzed
with the aid of a simulation from an eddy-resolving primitive equatio
n model of the North Pacific basin in the region of the Kuroshio and K
uroshio Extension. The model domain covers the Pacific Ocean north of
20 degrees S and has a resolution of 0.125 degrees latitude and 0.176
degrees longitude. The model is synoptically driven by daily 1000-mbar
winds from the European Centre for Medium-Range Weather Forecasts (EC
MWE) which encompass the Geosat time period. Model output is sampled a
long Geosat ground tracks for the period of the ERM. Additionally, the
model and the Geosat data are compared with climatological hydrograph
y and satellite IR frontal position analyses. Analyses compared includ
e maps of sea surface height (SSH) mean and variability, eddy kinetic
energy (EKE), seasonal transport anomaly, and time-longitude plots of
SSH anomaly. The model simulation provides annual mean SSH fields for
1987 and 1988 which reproduce the four quasi-permanent meanders seen i
n hydrographic climatology (cyclonic at 138 degrees E and anticyclonic
at 144 degrees E, 150 degrees E, and 160 degrees E). These are linked
to the bottom topography. In the model simulation, Geosat altimeter d
ata, and climatology, we observe four peaks in SSH variability associa
ted with meander activity and two peaks in EKE, with the strongest abo
ut 3200 cm(2) s(-2) along the mean Kuroshio path in the Geosat data. T
he local maxima in SSH variability tend to occur where relatively stro
ng, topographically steered meridional abyssal currents intersect the
zonally oriented Kuroshio Extension. Westward propagation of SSH anoma
lies at phase speeds of 2 to 3 cm s(-1) in the region east of 155 degr
ees E is observed in the model simulation and Geosat observations. A l
ate summer maximum in the upper ocean transport anomaly of the Kuroshi
o Extension is inferred from changes in the cross-stream differential
in SSH from the simulation and Geosat observations.