Observations of oppositely directed, monthly mean alongshore currents and wind stress over the continental margin off the Pacific coast of North America motivate the theoretical examination of mean flow generation by topographic lee-wave drag. We formulate a barotropic model for wind-forced shelf-slope flow over variable topography. Our central objective is...
A thermistor chain was towed 1400 km through the eastern North Pacific subtropical frontal zone in
January 1980. The observations resolve surface layer temperature features with horizontal wavelengths of
0.2-200 km and vertical scales of 10-70 m. The dominant features, which have horizontal wavelengths of
10-100 km, amplitudes of 0.2°-1.0°C,...
We formulate analytically and solve numerically a semigeostrophic model for wind-driven thermocline upwelling at a coastal boundary. The model has a variable-density entraining mixed layer and two homogeneous interior layers. All variables are uniform alongshore. The wind stress and surface heating are constant. The system is started from rest, with...
Data from an array of bottom pressure gauges and a string of current meters in the vicinity of 47°N,
139°W, are used to examine the deep-ocean variability forced by ocean surface wind stress curl from
August 1987 to June 1988. Bottom geostrophic currents are computed from the pressure gauge array,...
An approach developed recently to study the dynamics of vorticity defects in homogeneous
shear flow extends naturally to the case of baroclinic, quasi-geostrophic
flow. It is shown that an inviscid geostrophic flow with uniform vertical shear may
be destabilized by introducing a `potential vorticity defect', an arbitrarily small but
sufficiently...
Coastally trapped wind reversals along the U.S. west coast, which are often accompanied by a northward surge of fog or stratus, are an important warm—season forecast problem due to their impact on coastal maritime activities and airport operations. Previous studies identified several possible dynamic mechanisms that could be responsible for...
The dynamics of the growth of linear disturbances
to a chaotic basic state is analyzed in an asymptotic model of
weakly nonlinear, baroclinic wave-mean interaction. In this
model, an ordinary differential equation for the wave amplitude
is coupled to a partial differential equation for the zonal
flow correction. The leading...
The local predictability of the El Nin˜o–Southern Oscillation (ENSO) is examined by the analysis of the
evolution of small disturbances to an unstable 4.3-yr ENSO cycle in the Cane–Zebiak model forced by perpetual
July conditions. The 4.3-yr cycle represents the dominant near-recurrent behavior in this weakly chaotic regime,
so analysis...
The coastal ocean may experience periods of fluctuating
along-shelf wind direction, causing shifts between
upwelling and downwelling conditions with responses that
are not symmetric. We seek to understand these asymmetries
and their implications on the Eulerian and Lagrangian flows.
We use a two-dimensional (variations across-shelf and with
depth; uniformity along-shelf)...