The Santa Barbara Channel (SEC) is a coastal basin about 100 km long b
ounded by the Southern California mainland on the north and by a chain
of islands on the south. The SEC is at most 50 km wide and just over
600 m deep. The nature of current and wind variance peaks in the 2-4-d
ay and 4-6-day bands in the channel are analyzed from January to July
1984. For both bands the dominant empirical mode of the currents is hi
ghly coherent with the dominant empirical mode of the winds over this
region. Surface intensification of currents is revealed by measurement
s made between 25 and 300 m. In contrast the deeper currents are chara
cterized by bottom trapping. Evidence for baroclinic bottom-trapped to
pographic Rossby waves is found on the northern shelf at the western m
outh of the channel in both frequency bands. At 30 m the distribution
of phases shows currents at the center of the western mouth leading th
e southern interisland passes by about 0.3 day and the eastern mouth b
y about 0.6 day. In both bands co-and quadrature vectors of currents a
nd winds describe this wind-current system in detail. It is speculated
from spatial and temporal eigenfunctions of currents and winds and fr
om available satellite images that the dominant current mode described
above is a channelwide response to upwelling north of Point Conceptio
n (northwestward of the SEC). The upwelling-related currents cause a n
et inflow of mass into the western end of the channel, which is compen
sated by an outflow passing through both the interisland passes and th
rough the eastern mouth of the channel. As a result of the narrowness
and shallowness of the passes and of the shallowness of the southern s
helf in general, high flow speeds are attained there that, the authors
speculate, seem to force deep high-frequency motions both at the cent
er of the SEC and at the northern half of its western mouth.