A Wind and Boundary Driven Circulation Model
of the Ross Sea
V. COMMODARI1 AND S. PlERINI2
i Istituto di Meteorologia e Oceanografia, Istituto Universitario Navale, Via Amm. Acton 38,
80133 Napoli, Italy
2 Dipartimento di Fisica, Université dell’Aquila, Via Vetoio, 67100 Coppito (AQ), Italy
Abstract
The application of a barotropic primitive équation model to the Ross Sea has
allowed to détermine the main features of the vertically integrated transport as
induced locally by the wind and forced by the external action of the East Wind
Drift during the ice-free season. Furthermore, the implémentation of the same
model with higher resolution to a Coastal area including Terra Nova Bay has provided information on the local circulation régime. The circulation model of the
Ross Sea is implemented in a domain including the Ross Sea and an external zone
which allows for the formation of the Ross Sea gyre. A regular grid of 20 km resolution is defïned on a adapted Gauss-Boaga projection which reduces notably
the deformation of the distances. The model is first forced by an idealized wind
System representing schematically the local atmospheric circulation on a global
scale and the runs are carried out up to the steady State. The Ross Sea gyre and an
overall cyclonic circulation in the interior of the Ross Sea locally shaped by the
topography are observed. On the other hand, the response inside the Ross Sea to
the remote effect of a boundary forcing given by the Antarctic Circumpolar
Current and of the East Wind Drift in the absence of winds is found to be very
weak. This puts in evidence that the wind is by far the most energetic forcing of
the local barotropic circulation. These numerical results are found to be in good
agreement with classical observational data and with current meter measurements taken within the Italian P.N.R.A.. The model is then applied to a Coastal
zone around Terra nova Bay with a 2 km resolution. This model is forced by an
idealized wind and nested with the coarse resolution model of the Ross Sea.
Information are thus obtained on the local circulation.
1 Introduction
The Antarctic continent exerts a profound influence on both the global atmospheric circulation and the oceanic thermohaline and dynamic structure, thus
interfering with marine and terrestrial ecosystems. The oceanic circulation surrounding the continent can be roughly represented by two mainly wind-driven
currents, the Antarctic Circumpolar Current (ACC) flowing eastward and a
Coastal countercurrent, the East Wind Drift (EWD), which is strongly influenced
of the Ross Sea
V. COMMODARI1 AND S. PlERINI2
i Istituto di Meteorologia e Oceanografia, Istituto Universitario Navale, Via Amm. Acton 38,
80133 Napoli, Italy
2 Dipartimento di Fisica, Université dell’Aquila, Via Vetoio, 67100 Coppito (AQ), Italy
Abstract
The application of a barotropic primitive équation model to the Ross Sea has
allowed to détermine the main features of the vertically integrated transport as
induced locally by the wind and forced by the external action of the East Wind
Drift during the ice-free season. Furthermore, the implémentation of the same
model with higher resolution to a Coastal area including Terra Nova Bay has provided information on the local circulation régime. The circulation model of the
Ross Sea is implemented in a domain including the Ross Sea and an external zone
which allows for the formation of the Ross Sea gyre. A regular grid of 20 km resolution is defïned on a adapted Gauss-Boaga projection which reduces notably
the deformation of the distances. The model is first forced by an idealized wind
System representing schematically the local atmospheric circulation on a global
scale and the runs are carried out up to the steady State. The Ross Sea gyre and an
overall cyclonic circulation in the interior of the Ross Sea locally shaped by the
topography are observed. On the other hand, the response inside the Ross Sea to
the remote effect of a boundary forcing given by the Antarctic Circumpolar
Current and of the East Wind Drift in the absence of winds is found to be very
weak. This puts in evidence that the wind is by far the most energetic forcing of
the local barotropic circulation. These numerical results are found to be in good
agreement with classical observational data and with current meter measurements taken within the Italian P.N.R.A.. The model is then applied to a Coastal
zone around Terra nova Bay with a 2 km resolution. This model is forced by an
idealized wind and nested with the coarse resolution model of the Ross Sea.
Information are thus obtained on the local circulation.
1 Introduction
The Antarctic continent exerts a profound influence on both the global atmospheric circulation and the oceanic thermohaline and dynamic structure, thus
interfering with marine and terrestrial ecosystems. The oceanic circulation surrounding the continent can be roughly represented by two mainly wind-driven
currents, the Antarctic Circumpolar Current (ACC) flowing eastward and a
Coastal countercurrent, the East Wind Drift (EWD), which is strongly influenced