The Application of POM to the Cavity Beneath the Amery Ice Shelf
John Hunter
Antarctic Cooperative Research Centre
University of Tasmania, Australia
The Princeton Ocean Model is presently being applied to the ocean
cavity beneath the Amery Ice Shelf, Antarctica. The cavity covers
an area of about 60000 square km, and has a volume of about
20000 cubic km; it therefore occupies about the same area as Bass
Strait, Australia, but about five times the volume. The cavity
is covered by an ice shelf of average thickness about 600 metres,
which terminates at the ocean with a near-vertical ice cliff which
stretches to about 200m below the sea surface. The circulation is
characterized by buoyancy-driven currents (caused by melting and
re-freezing at the base of the ice shelf) occupying a boundary layer
which may be only tens of meters thick. Such a system can only
be feasibly simulated using a model which involves either sigma-
coordinates (or a variant of them) or isopycnic coordinates.
The presence of the ice cliff at the cavity entrance, and also the
often steeply sloping ice/water interface and sea bed, presents
a strong test of internal pressure errors and of the concept of
hydrostatic consistency in sigma-coordinate models.
The process of adapting POM to include an ice shelf and appropriate
ice/seawater thermodynamics will be described. Preliminary results
for the Amery Ice Shelf will be presented.