A particle-in-cell (PIC) numerical method developed for the study of shallo
w-water dynamics, when the moving fluid layer is laterally confined by the
intersection of its top and bottom surfaces, is described. The effect of am
bient rotation is included for application to geophysical fluids, particula
rly open-ocean buoyant vortices in which the underlying density interface o
utcrops to the surface around the rim of the vortex. Extensions to include
the dynamical effect of a second moving layer (baroclinicity) and the prese
nce of a lateral rigid boundary (sidewall) are also described. Although the
method was developed for oceanographic investigations, applications to oth
er fluid mechanics problems would be straightforward. Copyright (C) 2000 Jo
hn Wiley & Sons, Ltd.